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Sample records for phase protein app

  1. The Alzheimer Amyloid Precursor Protein (APP) and Fe65, an APP-Binding Protein, Regulate Cell Movement

    PubMed Central

    Sabo, Shasta L.; Ikin, Annat F.; Buxbaum, Joseph D.; Greengard, Paul

    2001-01-01

    FE65 binds to the Alzheimer amyloid precursor protein (APP), but the function of this interaction has not been identified. Here, we report that APP and FE65 are involved in regulation of cell movement. APP and FE65 colocalize with actin and Mena, an Abl-associated signaling protein thought to regulate actin dynamics, in lamellipodia. APP and FE65 specifically concentrate with β1-integrin in dynamic adhesion sites known as focal complexes, but not in more static adhesion sites known as focal adhesions. Overexpression of APP accelerates cell migration in an MDCK cell wound–healing assay. Coexpression of APP and FE65 dramatically enhances the effect of APP on cell movement, probably by regulating the amount of APP at the cell surface. These data are consistent with a role for FE65 and APP, possibly in a Mena-containing macromolecular complex, in regulation of actin-based motility. PMID:11425871

  2. Alternative splicing regulation of APP exon 7 by RBFox proteins.

    PubMed

    Alam, Shafiul; Suzuki, Hitoshi; Tsukahara, Toshifumi

    2014-12-01

    RBFox proteins are well-known alternative splicing regulators. We have shown previously that during neuronal differentiation of P19 cells induced by all-trans retinoic acid and cell aggregation, RBFox1 shows markedly increased temporal expression. To find its key splicing regulation, we examined the effect of RBFox1 on 33 previously reported and validated neuronal splicing events of P19 cells. We observed that alternative splicing of three genes, specifically, amyloid precursor protein (APP), disks large homolog 3 (DLG3), and G protein, alpha activating activity polypeptide O (GNAO1), was altered by transient RBFox1 expression in HEK293 and HeLa cells. Moreover, an RBFox1 mutant (RBFox1FA) that was unable to bind the target RNA sequence ((U)GCAUG) did not induce these splicing events. APP generates amyloid beta peptides that are involved in the pathology of Alzheimer's disease, and therefore we examined APP alternative splicing regulation by RBFox1 and other splicing regulators. Our results indicated that RBFox proteins promote the skipping of APP exon 7, but not the inclusion of exon 8. We made APP6789 minigenes and observed that two (U)GCAUG sequences, located upstream of exon 7 and in exon 7, functioned to induce skipping of exon 7 by RBFox proteins. Overall, RBFox proteins may shift APP from exon 7 containing isoforms, APP770 and APP751, toward the exon 7 lacking isoform, APP695, which is predominant in neural tissues.

  3. Therapeutic Potential of Secreted Amyloid Precursor Protein APPsα

    PubMed Central

    Mockett, Bruce G.; Richter, Max; Abraham, Wickliffe C.; Müller, Ulrike C.

    2017-01-01

    Cleavage of the amyloid precursor protein (APP) by α-secretase generates an extracellularly released fragment termed secreted APP-alpha (APPsα). Not only is this process of interest due to the cleavage of APP within the amyloid-beta sequence, but APPsα itself has many physiological properties that suggest its great potential as a therapeutic target. For example, APPsα is neurotrophic, neuroprotective, neurogenic, a stimulator of protein synthesis and gene expression, and enhances long-term potentiation (LTP) and memory. While most early studies have been conducted in vitro, effectiveness in animal models is now being confirmed. These studies have revealed that either upregulating α-secretase activity, acutely administering APPsα or chronic delivery of APPsα via a gene therapy approach can effectively treat mouse models of Alzheimer’s disease (AD) and other disorders such as traumatic head injury. Together these findings suggest the need for intensifying research efforts to harness the therapeutic potential of this multifunctional protein. PMID:28223920

  4. The polarity protein Par3 regulates APP trafficking and processing through the endocytic adaptor protein Numb.

    PubMed

    Sun, Miao; Asghar, Suwaiba Z; Zhang, Huaye

    2016-09-01

    The processing of amyloid precursor protein (APP) into β-amyloid peptide (Aβ) is a key step in the pathogenesis of Alzheimer's disease (AD), and trafficking dysregulations of APP and its secretases contribute significantly to altered APP processing. Here we show that the cell polarity protein Par3 plays an important role in APP processing and trafficking. We found that the expression of full length Par3 is significantly decreased in AD patients. Overexpression of Par3 promotes non-amyloidogenic APP processing, while depletion of Par3 induces intracellular accumulation of Aβ. We further show that Par3 functions by regulating APP trafficking. Loss of Par3 decreases surface expression of APP by targeting APP to the late endosome/lysosome pathway. Finally, we show that the effects of Par3 are mediated through the endocytic adaptor protein Numb, and Par3 functions by interfering with the interaction between Numb and APP. Together, our studies show a novel role for Par3 in regulating APP processing and trafficking.

  5. [Acute-phase proteins in inflammation].

    PubMed

    Engler, R

    1995-01-01

    The acute phase proteins (APPs) have been empirically defined as those whose plasma concentration changes following inflammatory reaction. Those proteins whose concentrations increase are referred to as positive APP, while those whose levels decline are termed negative APP. In man, positive APP are: alpha 1 acid glycoprotein, alpha 1 protease inhibitor, alpha 1 antichymotrypsin, haptoglobin, ceruloplasmin, fibrinogen, C-reactive protein, serum amyloid A. Great variability in the APP response between different species is observed. The principal functions of APP, result from the interaction of these proteins with ligands of various origins which give "protein-ligands" complexes. These complexes are cleared by the RES or by the hepatocyte. The results are protease inhibition, neutralization of toxic molecules such as hemoglobin or the superoxide anion, clearance of cell membranes and chromatin. The drop of the plasma concentration of negative APP during an inflammatory reaction carries a rise of free ligands (fatty acids, hormones, vitamins, trace elements). IL6 has been recognized as the principal regulator of most APP genes. The response of the hepatic cell to IL6 is characterized by the enhanced production of type 2 or IL6 specific APPs. The biochemical process of signal transduction is IL6--JAK2--APRF The set of APP genes regulated by IL1 type cytokines (type 1 APPs) is distinct from that regulated by IL6 type cytokine. IL1 and TNF alpha mediated stimulation of type 1 APP genes is synergistically enhanced by IL6 type cytokines. The biochemical process of signal transduction is IL1, IL6--Ras--MAP kinase--NFIL6 The targeted inflammatory proteic profile including the assay of C-reactive protein, haptoglobin and alpha 1 acid glycoprotein produces a "biological tool" to the clinician in order to manage an inflammatory response. IL6, a proteic marker for the future, connected with CRP, will be assayed during early inflammatory reaction.

  6. Biochemical isolation of Argonaute protein complexes by Ago-APP

    PubMed Central

    Hauptmann, Judith; Schraivogel, Daniel; Bruckmann, Astrid; Manickavel, Sudhir; Jakob, Leonhard; Eichner, Norbert; Pfaff, Janina; Urban, Marc; Sprunck, Stefanie; Hafner, Markus; Tuschl, Thomas; Deutzmann, Rainer; Meister, Gunter

    2015-01-01

    During microRNA (miRNA)-guided gene silencing, Argonaute (Ago) proteins interact with a member of the TNRC6/GW protein family. Here we used a short GW protein-derived peptide fused to GST and demonstrate that it binds to Ago proteins with high affinity. This allows for the simultaneous isolation of all Ago protein complexes expressed in diverse species to identify associated proteins, small RNAs, or target mRNAs. We refer to our method as “Ago protein Affinity Purification by Peptides“ (Ago-APP). Furthermore, expression of this peptide competes for endogenous TNRC6 proteins, leading to global inhibition of miRNA function in mammalian cells. PMID:26351695

  7. APP independent and dependent effects on neurite outgrowth are modulated by the receptor associated protein (RAP).

    PubMed

    Billnitzer, Andrew J; Barskaya, Irina; Yin, Cailing; Perez, Ruth G

    2013-01-01

    Amyloid precursor protein (APP) and its secreted form, sAPP, contribute to the development of neurons in hippocampus, a brain region critical for learning and memory. Full-length APP binds the low-density lipoprotein receptor-related protein (LRP), which stimulates APP endocytosis. LRP also contributes to neurite growth. Furthermore, the receptor associated protein (RAP) binds LRP in a manner that blocks APP-LRP interactions. To elucidate APP contributions to neurite growth for full-length APP and sAPP, we cultured wild type (WT) and APP knockout (KO) neurons in sAPPα and/or RAP and measured neurite outgrowth at 1 day in vitro. Our data reveal that WT neurons had less axonal outgrowth including less axon branching. RAP treatment potentiated the inhibitory effects of APP. KO neurons had significantly more outgrowth and branching, especially in response to RAP, effects which were also associated with ERK2 activation. Our results affirm a major inhibitory role by full-length APP on all aspects of axonal and dendritic outgrowth, and show that RAP-LRP binding stimulated axon growth independently of APP. These findings support a major role for APP as an inhibitor of neurite growth and reveal novel signaling functions for LRP that may be disrupted by Alzheimer's pathology or therapies aimed at APP processing.

  8. Amyloid precursor protein (APP) affects global protein synthesis in dividing human cells.

    PubMed

    Sobol, Anna; Galluzzo, Paola; Liang, Shuang; Rambo, Brittany; Skucha, Sylvia; Weber, Megan J; Alani, Sara; Bocchetta, Maurizio

    2015-05-01

    Hypoxic non-small cell lung cancer (NSCLC) is dependent on Notch-1 signaling for survival. Targeting Notch-1 by means of γ-secretase inhibitors (GSI) proved effective in killing hypoxic NSCLC. Post-mortem analysis of GSI-treated, NSCLC-burdened mice suggested enhanced phosphorylation of 4E-BP1 at threonines 37/46 in hypoxic tumor tissues. In vitro dissection of this phenomenon revealed that Amyloid Precursor Protein (APP) inhibition was responsible for a non-canonical 4E-BP1 phosphorylation pattern rearrangement-a process, in part, mediated by APP regulation of the pseudophosphatase Styx. Upon APP depletion we observed modifications of eIF-4F composition indicating increased recruitment of eIF-4A to the mRNA cap. This phenomenon was supported by the observation that cells with depleted APP were partially resistant to silvestrol, an antibiotic that interferes with eIF-4A assembly into eIF-4F complexes. APP downregulation in dividing human cells increased the rate of global protein synthesis, both cap- and IRES-dependent. Such an increase seemed independent of mTOR inhibition. After administration of Torin-1, APP downregulation and Mechanistic Target of Rapamycin Complex 1 (mTORC-1) inhibition affected 4E-BP1 phosphorylation and global protein synthesis in opposite fashions. Additional investigations indicated that APP operates independently of mTORC-1. Key phenomena described in this study were reversed by overexpression of the APP C-terminal domain. The presented data suggest that APP may be a novel regulator of protein synthesis in dividing human cells, both cancerous and primary. Furthermore, APP appears to affect translation initiation using mechanisms seemingly dissimilar to mTORC-1 regulation of cap-dependent protein synthesis.

  9. Acute phase reaction and acute phase proteins*

    PubMed Central

    Gruys, E.; Toussaint, M.J.M.; Niewold, T.A.; Koopmans, S.J.

    2005-01-01

    A review of the systemic acute phase reaction with major cytokines involved, and the hepatic metabolic changes, negative and positive acute phase proteins (APPs) with function and associated pathology is given. It appears that APPs represent appropriate analytes for assessment of animal health. Whereas they represent non-specific markers as biological effect reactants, they can be used for assessing nutritional deficits and reactive processes, especially when positive and negative acute phase variables are combined in an index. When such acute phase index is applied to separate healthy animals from animals with some disease, much better results are obtained than with single analytes and statistically acceptable results for culling individual animals may be reached. Unfortunately at present no cheap, comprehensive and easy to use system is available for assessing various acute phase proteins in serum or blood samples at the same time. Protein microarray or fluid phase microchip technology may satisfy this need; and permit simultaneous analysis of numerous analytes in the same small volume sample and enable integration of information derived from systemic reactivity and nutrition with disease specific variables. Applying such technology may help to solve health problems in various countries not only in animal husbandry but also in human populations. PMID:16252337

  10. Lost region in amyloid precursor protein (APP) through TALEN-mediated genome editing alters mitochondrial morphology.

    PubMed

    Wang, Yajie; Wu, Fengyi; Pan, Haining; Zheng, Wenzhong; Feng, Chi; Wang, Yunfu; Deng, Zixin; Wang, Lianrong; Luo, Jie; Chen, Shi

    2016-02-29

    Alzheimer's disease (AD) is characterized by amyloid-β (Aβ) deposition in the brain. Aβ plaques are produced through sequential β/γ cleavage of amyloid precursor protein (APP), of which there are three main APP isoforms: APP695, APP751 and APP770. KPI-APPs (APP751 and APP770) are known to be elevated in AD, but the reason remains unclear. Transcription activator-like (TAL) effector nucleases (TALENs) induce mutations with high efficiency at specific genomic loci, and it is thus possible to knock out specific regions using TALENs. In this study, we designed and expressed TALENs specific for the C-terminus of APP in HeLa cells, in which KPI-APPs are predominantly expressed. The KPI-APP mutants lack a 12-aa region that encompasses a 5-aa trans-membrane (TM) region and 7-aa juxta-membrane (JM) region. The mutated KPI-APPs exhibited decreased mitochondrial localization. In addition, mitochondrial morphology was altered, resulting in an increase in spherical mitochondria in the mutant cells through the disruption of the balance between fission and fusion. Mitochondrial dysfunction, including decreased ATP levels, disrupted mitochondrial membrane potential, increased ROS generation and impaired mitochondrial dehydrogenase activity, was also found. These results suggest that specific regions of KPI-APPs are important for mitochondrial localization and function.

  11. Expression of APP pathway mRNAs and proteins in Alzheimer's disease.

    PubMed

    Matsui, Toshifumi; Ingelsson, Martin; Fukumoto, Hiroaki; Ramasamy, Karunya; Kowa, Hisatomo; Frosch, Matthew P; Irizarry, Michael C; Hyman, Bradley T

    2007-08-03

    In both trisomy 21 and rare cases of triplication of amyloid precursor protein (APP) Alzheimer's disease (AD) pathological changes are believed to be secondary to increased expression of APP. We hypothesized that sporadic AD may also be associated with changes in transcription of APP or its metabolic partners. To address this issue, temporal neocortex of 27 AD and 21 non-demented control brains was examined to assess mRNA levels of APP isoforms (total APP, APP containing the Kunitz protease inhibitor domain [APP-KPI] and APP770) and APP metabolic enzymatic partners (the APP cleaving enzymes beta-secretase [BACE] and presenilin-1 [PS-1], and putative clearance molecules, low-density lipoprotein receptor protein [LRP] and apolipoprotein E [apoE]). Furthermore, we evaluated how changes in APP at the mRNA level affect the amount of Tris buffer extractable APP protein and Abeta40 and 42 peptides in AD and control brains. As assessed by quantitative PCR, APP-KPI (p=0.007), APP770 (p=0.004), PS-1 (p=0.004), LRP (p=0.003), apoE (p=0.0002) and GFAP (p<0.0001) mRNA levels all increased in AD, and there was a shift from APP695 (a neuronal isoform) towards KPI containing isoforms that are present in glia as well. APP-KPI mRNA levels correlated with soluble APPalpha-KPI protein (sAPPalpha-KPI) levels measured by ELISA (tau=0.33, p=0.015 by Kendall's rank correlation); in turn, soluble APPalpha-KPI protein levels positively correlated with Tris-extractable, soluble Abeta40 (p=0.046) and 42 levels (p=0.007). The ratio of soluble APPalpha-KPI protein levels to total APP protein increased in AD, and also correlated with GFAP protein levels in AD. These results suggest that altered transcription of APP in AD is proportionately associated with Abeta peptide, may occur in the context of gliosis, and may contribute to Abeta deposition in sporadic AD.

  12. Insulin-like growth factor-1 (IGF-1)-induced processing of amyloid-beta precursor protein (APP) and APP-like protein 2 is mediated by different metalloproteinases.

    PubMed

    Jacobsen, Kristin T; Adlerz, Linda; Multhaup, Gerd; Iverfeldt, Kerstin

    2010-04-02

    alpha-Secretase cleavage of the amyloid precursor protein (APP) is of great interest because it prevents the formation of the Alzheimer-linked amyloid-beta peptide. APP belongs to a conserved gene family including the two paralogues APP-like protein (APLP) 1 and 2. Insulin-like growth factor-1 (IGF-1) stimulates the shedding of all three proteins. IGF-1-induced shedding of both APP and APLP1 is dependent on phosphatidylinositol 3-kinase (PI3-K), whereas APLP2 shedding is independent of this signaling pathway. Here, we used human neuroblastoma SH-SY5Y cells to investigate the involvement of protein kinase C (PKC) in the proteolytic processing of endogenously expressed members of the APP family. Processing was induced by IGF-1 or retinoic acid, another known stimulator of APP alpha-secretase shedding. Our results show that stimulation of APP and APLP1 processing involves multiple signaling pathways, whereas APLP2 processing is mainly dependent on PKC. Next, we wanted to investigate whether the difference in the regulation of APLP2 shedding compared with APP shedding could be due to involvement of different processing enzymes. We focused on the two major alpha-secretase candidates ADAM10 and TACE, which both are members of the ADAM (a disintegrin and metalloprotease) family. Shedding was analyzed in the presence of the ADAM10 inhibitor GI254023X, or after transfection with small interfering RNAs targeted against TACE. The results clearly demonstrate that different alpha-secretases are involved in IGF-1-induced processing. APP is mainly cleaved by ADAM10, whereas APLP2 processing is mediated by TACE. Finally, we also show that IGF-1 induces PKC-dependent phosphorylation of TACE.

  13. Insulin-like Growth Factor-1 (IGF-1)-induced Processing of Amyloid-β Precursor Protein (APP) and APP-like Protein 2 Is Mediated by Different Metalloproteinases*

    PubMed Central

    Jacobsen, Kristin T.; Adlerz, Linda; Multhaup, Gerd; Iverfeldt, Kerstin

    2010-01-01

    α-Secretase cleavage of the amyloid precursor protein (APP) is of great interest because it prevents the formation of the Alzheimer-linked amyloid-β peptide. APP belongs to a conserved gene family including the two paralogues APP-like protein (APLP) 1 and 2. Insulin-like growth factor-1 (IGF-1) stimulates the shedding of all three proteins. IGF-1-induced shedding of both APP and APLP1 is dependent on phosphatidylinositol 3-kinase (PI3-K), whereas APLP2 shedding is independent of this signaling pathway. Here, we used human neuroblastoma SH-SY5Y cells to investigate the involvement of protein kinase C (PKC) in the proteolytic processing of endogenously expressed members of the APP family. Processing was induced by IGF-1 or retinoic acid, another known stimulator of APP α-secretase shedding. Our results show that stimulation of APP and APLP1 processing involves multiple signaling pathways, whereas APLP2 processing is mainly dependent on PKC. Next, we wanted to investigate whether the difference in the regulation of APLP2 shedding compared with APP shedding could be due to involvement of different processing enzymes. We focused on the two major α-secretase candidates ADAM10 and TACE, which both are members of the ADAM (a disintegrin and metalloprotease) family. Shedding was analyzed in the presence of the ADAM10 inhibitor GI254023X, or after transfection with small interfering RNAs targeted against TACE. The results clearly demonstrate that different α-secretases are involved in IGF-1-induced processing. APP is mainly cleaved by ADAM10, whereas APLP2 processing is mediated by TACE. Finally, we also show that IGF-1 induces PKC-dependent phosphorylation of TACE. PMID:20139073

  14. Role of APP Interactions with Heterotrimeric G Proteins: Physiological Functions and Pathological Consequences.

    PubMed

    Copenhaver, Philip F; Kögel, Donat

    2017-01-01

    Following the discovery that the amyloid precursor protein (APP) is the source of β-amyloid peptides (Aβ) that accumulate in Alzheimer's disease (AD), structural analyses suggested that the holoprotein resembles a transmembrane receptor. Initial studies using reconstituted membranes demonstrated that APP can directly interact with the heterotrimeric G protein Gαo (but not other G proteins) via an evolutionarily G protein-binding motif in its cytoplasmic domain. Subsequent investigations in cell culture showed that antibodies against the extracellular domain of APP could stimulate Gαo activity, presumably mimicking endogenous APP ligands. In addition, chronically activating wild type APP or overexpressing mutant APP isoforms linked with familial AD could provoke Go-dependent neurotoxic responses, while biochemical assays using human brain samples suggested that the endogenous APP-Go interactions are perturbed in AD patients. More recently, several G protein-dependent pathways have been implicated in the physiological roles of APP, coupled with evidence that APP interacts both physically and functionally with Gαo in a variety of contexts. Work in insect models has demonstrated that the APP ortholog APPL directly interacts with Gαo in motile neurons, whereby APPL-Gαo signaling regulates the response of migratory neurons to ligands encountered in the developing nervous system. Concurrent studies using cultured mammalian neurons and organotypic hippocampal slice preparations have shown that APP signaling transduces the neuroprotective effects of soluble sAPPα fragments via modulation of the PI3K/Akt pathway, providing a mechanism for integrating the stress and survival responses regulated by APP. Notably, this effect was also inhibited by pertussis toxin, indicating an essential role for Gαo/i proteins. Unexpectedly, C-terminal fragments (CTFs) derived from APP have also been found to interact with Gαs, whereby CTF-Gαs signaling can promote neurite outgrowth

  15. Role of APP Interactions with Heterotrimeric G Proteins: Physiological Functions and Pathological Consequences

    PubMed Central

    Copenhaver, Philip F.; Kögel, Donat

    2017-01-01

    Following the discovery that the amyloid precursor protein (APP) is the source of β-amyloid peptides (Aβ) that accumulate in Alzheimer’s disease (AD), structural analyses suggested that the holoprotein resembles a transmembrane receptor. Initial studies using reconstituted membranes demonstrated that APP can directly interact with the heterotrimeric G protein Gαo (but not other G proteins) via an evolutionarily G protein-binding motif in its cytoplasmic domain. Subsequent investigations in cell culture showed that antibodies against the extracellular domain of APP could stimulate Gαo activity, presumably mimicking endogenous APP ligands. In addition, chronically activating wild type APP or overexpressing mutant APP isoforms linked with familial AD could provoke Go-dependent neurotoxic responses, while biochemical assays using human brain samples suggested that the endogenous APP-Go interactions are perturbed in AD patients. More recently, several G protein-dependent pathways have been implicated in the physiological roles of APP, coupled with evidence that APP interacts both physically and functionally with Gαo in a variety of contexts. Work in insect models has demonstrated that the APP ortholog APPL directly interacts with Gαo in motile neurons, whereby APPL-Gαo signaling regulates the response of migratory neurons to ligands encountered in the developing nervous system. Concurrent studies using cultured mammalian neurons and organotypic hippocampal slice preparations have shown that APP signaling transduces the neuroprotective effects of soluble sAPPα fragments via modulation of the PI3K/Akt pathway, providing a mechanism for integrating the stress and survival responses regulated by APP. Notably, this effect was also inhibited by pertussis toxin, indicating an essential role for Gαo/i proteins. Unexpectedly, C-terminal fragments (CTFs) derived from APP have also been found to interact with Gαs, whereby CTF-Gαs signaling can promote neurite

  16. APP overexpression in the absence of NPC1 exacerbates metabolism of amyloidogenic proteins of Alzheimer's disease

    PubMed Central

    Maulik, Mahua; Peake, Kyle; Chung, JiYun; Wang, Yanlin; Vance, Jean E.; Kar, Satyabrata

    2015-01-01

    Amyloid-β (Aβ) peptides originating from β-amyloid precursor protein (APP) are critical in Alzheimer's disease (AD). Cellular cholesterol levels/distribution can regulate production and clearance of Aβ peptides, albeit with contradictory outcomes. To better understand the relationship between cholesterol homeostasis and APP/Aβ metabolism, we have recently generated a bigenic ANPC mouse line overexpressing mutant human APP in the absence of Niemann-Pick type C-1 protein required for intracellular cholesterol transport. Using this unique bigenic ANPC mice and complementary stable N2a cells, we have examined the functional consequences of cellular cholesterol sequestration in the endosomal–lysosomal system, a major site of Aβ production, on APP/Aβ metabolism and its relation to neuronal viability. Levels of APP C-terminal fragments (α-CTF/β-CTF) and Aβ peptides, but not APP mRNA/protein or soluble APPα/APPβ, were increased in ANPC mouse brains and N2a-ANPC cells. These changes were accompanied by reduced clearance of peptides and an increased level/activity of γ-secretase, suggesting that accumulation of APP-CTFs is due to decreased turnover, whereas increased Aβ levels may result from a combination of increased production and decreased turnover. APP-CTFs and Aβ peptides were localized primarily in early-/late-endosomes and to some extent in lysosomes/autophagosomes. Cholesterol sequestration impaired endocytic-autophagic-lysosomal, but not proteasomal, clearance of APP-CTFs/Aβ peptides. Moreover, markers of oxidative stress were increased in vulnerable brain regions of ANPC mice and enhanced β-CTF/Aβ levels increased susceptibility of N2a-ANPC cells to H2O2-induced toxicity. Collectively, our results show that cellular cholesterol sequestration plays a key role in APP/Aβ metabolism and increasing neuronal vulnerability to oxidative stress in AD-related pathology. PMID:26433932

  17. SorCS1 variants and amyloid precursor protein (APP) are co-transported in neurons but only SorCS1c modulates anterograde APP transport.

    PubMed

    Hermey, Guido; Schmidt, Nadine; Bluhm, Björn; Mensching, Daniel; Ostermann, Kristina; Rupp, Carsten; Kuhl, Dietmar; Kins, Stefan

    2015-10-01

    Processing of amyloid precursor protein (APP) into amyloid-β peptide (Aβ) is crucial for the development of Alzheimer's disease (AD). Because this processing is highly dependent on its intracellular itinerary, altered subcellular targeting of APP is thought to directly affect the degree to which Aβ is generated. The sorting receptor SorCS1 has been genetically linked to AD, but the underlying molecular mechanisms are poorly understood. We analyze two SorCS1 variants; one, SorCS1c, conveys internalization of surface-bound ligands whereas the other, SorCS1b, does not. In agreement with previous studies, we demonstrate co-immunoprecipitation and co-localization of both SorCS1 variants with APP. Our results suggest that SorCS1c and APP are internalized independently, although they mostly share a common post-endocytic pathway. We introduce functional Venus-tagged constructs to study SorCS1b and SorCS1c in living cells. Both variants are transported by fast anterograde axonal transport machinery and about 30% of anterograde APP-positive transport vesicles contain SorCS1. Co-expression of SorCS1b caused no change of APP transport kinetics, but SorCS1c reduced the anterograde transport rate of APP and increased the number of APP-positive stationary vesicles. These data suggest that SorCS1 and APP share trafficking pathways and that SorCS1c can retain APP from insertion into anterograde transport vesicles. Altered APP trafficking is thought to modulate its processing. SorCS1 has been suggested to function in APP trafficking. We analyzed if the two SorCS1 variants, SorCS1b and SorCS1c, tie APP to the cell surface or modify its internalization and intracellular targeting. We observed co-localization and vesicular co-transport of APP and SorCS1, but independent internalization and sorting through a common post-endocytic pathway. Co-expression of one variant, SorCS1c, reduced anterograde APP transport. These data demonstrate that SorCS1 and APP share trafficking pathways and

  18. AChE and the amyloid precursor protein (APP) - Cross-talk in Alzheimer's disease.

    PubMed

    Nalivaeva, Natalia N; Turner, Anthony J

    2016-11-25

    The amyloid precursor protein (APP) and acetylcholinesterase (AChE) are multi-faceted proteins with a wide range of vital functions, both crucially linked with the pathogenesis of Alzheimer's disease (AD). APP is the precursor of the Aβ peptide, the pathological agent in AD, while AChE is linked to its pathogenesis either by increasing cholinergic deficit or exacerbating Aβ fibril formation and toxicity. As such, both proteins are the main targets in AD therapeutics with AChE inhibitors being currently the only clinically available AD drugs. In our studies we have demonstrated an important inter-relation in functioning of these proteins. Both can be released from the cell membrane and we have shown that AChE shedding involves a metalloproteinase-mediated mechanism which, like the α-secretase dependent cleavage of APP, is stimulated by cholinergic agonists. Overexpression of the neuronal specific isoform APP695 in neuronal cells substantially decreased levels of the AChE mRNA, protein and catalytic activity accompanied by a similar decrease in mRNA levels of the AChE membrane anchor, PRiMA (proline rich membrane anchor). We further established that this regulation does not involve APP processing and its intracellular domain (AICD) but requires the E1 region of APP, specifically its copper-binding domain. On the contrary, siRNA knock-down of APP in cholinergic SN56 cells resulted in a significant upregulation of AChE mRNA levels. Hence APP may influence AChE physiology while released AChE may regulate amyloidogenesis through multiple mechanisms suggesting novel therapeutic targets.

  19. Upregulation of PGC-1α expression by Alzheimer’s disease-associated pathway: presenilin 1/amyloid precursor protein (APP)/intracellular domain of APP

    PubMed Central

    Robinson, Ari; Grösgen, Sven; Mett, Janine; Zimmer, Valerie C; Haupenthal, Viola J; Hundsdörfer, Benjamin; P Stahlmann, Christoph; Slobodskoy, Yulia; Müller, Ulrike C; Hartmann, Tobias; Stein, Reuven; Grimm, Marcus O W

    2014-01-01

    Cleavage of amyloid precursor protein (APP) by β- and γ-secretase generates amyloid-β (Aβ) and APP intracellular domain (AICD) peptides. Presenilin (PS) 1 or 2 is the catalytic component of the γ-secretase complex. Mitochondrial dysfunction is an established phenomenon in Alzheimer’s disease (AD), but the causes and role of PS1, APP, and APP’s cleavage products in this process are largely unknown. We studied the effect of these AD-associated molecules on mitochondrial features. Using cells deficient in PSs expression, expressing human wild-type PS1, or PS1 familial AD (FAD) mutants, we found that PS1 affects mitochondrial energy metabolism (ATP levels and oxygen consumption) and expression of mitochondrial proteins. These effects were associated with enhanced expression of the mitochondrial master transcriptional coactivator PGC-1α and its target genes. Importantly, PS1-FAD mutations decreased PS1’s ability to enhance PGC-1α mRNA levels. Analyzing the effect of APP and its γ-secretase-derived cleavage products Aβ and AICD on PGC-1α expression showed that APP and AICD increase PGC-1α expression. Accordingly, PGC-1α mRNA levels in cells deficient in APP/APLP2 or expressing APP lacking its last 15 amino acids were lower than in control cells, and treatment with AICD, but not with Aβ, enhanced PGC-1α mRNA levels in these and PSs-deficient cells. In addition, knockdown of the AICD-binding partner Fe65 reduced PGC-1α mRNA levels. Importantly, APP/AICD increases PGC-1α expression also in the mice brain. Our results therefore suggest that APP processing regulates mitochondrial function and that impairments in the newly discovered PS1/APP/AICD/PGC-1α pathway may lead to mitochondrial dysfunction and neurodegeneration. PMID:24304563

  20. Protein expression of BACE1, BACE2 and APP in Down syndrome brains.

    PubMed

    Cheon, M S; Dierssen, M; Kim, S H; Lubec, G

    2008-08-01

    Down syndrome (DS) is the most common human chromosomal abnormality caused by an extra copy of chromosome 21. The phenotype of DS is thought to result from overexpression of a gene or genes located on the triplicated chromosome or chromosome region. Several reports have shown that the neuropathology of DS comprises developmental abnormalities and Alzheimer-like lesions such as senile plaques. A key component of senile plaques is amyloid beta-peptide which is generated from the amyloid precursor protein (APP) by sequential action of beta-secretases (BACE1 and BACE2) and gamma-secretase. While BACE1 maps to chromosome 11, APP and BACE2 are located on chromosome 21. To challenge the gene dosage effect and gain insight into the expressional relation between beta-secretases and APP in DS brain, we evaluated protein expression levels of BACE1, BACE2 and APP in fetal and adult DS brain compared to controls. In fetal brain, protein expression levels of BACE2 and APP were comparable between DS and controls. BACE1 was increased, but did not reach statistical significance. In adult brain, BACE1 and BACE2 were comparable between DS and controls, but APP was significantly increased. We conclude that APP overexpression seems to be absent during the development of DS brain up to 18-19 weeks of gestational age. However, its overexpression in adult DS brain could lead to disturbance of normal function of APP contributing to neurodegeneration. Comparable expression of BACE1 and BACE2 speaks against the hypothesis that increased beta-secretase results in (or even underlies) increased production of amyloidogenic A beta fragments. Furthermore, current data indicate that the DS phenotype cannot be fully explained by simple gene dosage effect.

  1. BECN1/Beclin 1 sorts cell-surface APP/amyloid β precursor protein for lysosomal degradation.

    PubMed

    Swaminathan, Gayathri; Zhu, Wan; Plowey, Edward D

    2016-12-01

    The regulation of plasma membrane (PM)-localized transmembrane protein/receptor trafficking has critical implications for cell signaling, metabolism and survival. In this study, we investigated the role of BECN1 (Beclin 1) in the degradative trafficking of PM-associated APP (amyloid β precursor protein), whose metabolism to amyloid-β, an essential event in Alzheimer disease, is dependent on divergent PM trafficking pathways. We report a novel interaction between PM-associated APP and BECN1 that recruits macroautophagy/endosomal regulatory proteins PIK3C3 and UVRAG. We found that BECN1 promotes surface APP internalization and sorting predominantly to endosomes and endolysosomes. BECN1 also promotes the targeting of a smaller fraction of internalized APP to LC3-positive phagophores, suggesting a role for BECN1-dependent PM macroautophagy in APP degradation. Furthermore, BECN1 facilitates lysosomal degradation of surface APP and reduces the secretion of APP metabolites (soluble ectodomains, sAPP). The association between APP and BECN1 is dependent on the evolutionarily conserved domain (ECD) of BECN1 (amino acids 267-337). Deletion of a BECN1 ECD subregion (amino acids 285-299) did not impair BECN1- PIK3C3 interaction, PtdIns3K function or macroautophagy, but was sufficient to impair the APP-BECN1 interaction and BECN1's effects on surface APP internalization and degradation, resulting in increased secretion of sAPPs. Interestingly, both the BECN1-APP association and BECN1-dependent APP endocytosis and degradative trafficking were negatively regulated by active AKT. Our results further implicate phosphorylation of the BECN1 Ser295 residue in the inhibition of APP degradation by AKT. Our studies reveal a novel function for BECN1 in the sorting of a plasma membrane protein for endolysosomal and macroautophagic degradation.

  2. Deposition of BACE-1 Protein in the Brains of APP/PS1 Double Transgenic Mice

    PubMed Central

    Luo, Gang; Xu, Hongxia; Huang, Yinuo; Mo, Dapeng; Song, Ligang; Jia, Baixue; Wang, Bo; Jin, Zhanqiang; Miao, Zhongrong

    2016-01-01

    The main causes of Alzheimer's disease remain elusive. Previous data have implicated the BACE-1 protein as a central player in the pathogenesis of Alzheimer's disease. However, many inhibitors of BACE-1 have failed during preclinical and clinical trials for AD treatment. Therefore, uncovering the exact role of BACE-1 in AD may have significant impact on the future development of therapeutic agents. Three- and six-month-old female APP/PS1 double transgenic mice were used to study abnormal accumulation of BACE-1 protein in brains of mice here. Immunofluorescence, immunohistochemistry, and western blot were performed to measure the distributing pattern and expression level of BACE-1. We found obvious BACE-1 protein accumulation in 3-month-old APP/PS1 mice, which had increased by the time of 6 months. Coimmunostaining results showed BACE-1 surrounded amyloid plaques in brain sections. The abnormal protein expression might not be attributable to the upregulation of BACE-1 protein, as no significant difference of protein expression was observed between wild-type and APP/PS1 mice. With antibodies against BACE-1 and CD31, we found a high immunoreactive density of BACE-1 protein on the outer layer of brain blood vessels. The aberrant distribution of BACE-1 in APP/PS1 mice suggests BACE-1 may be involved in the microvascular abnormality of AD. PMID:27294139

  3. PTMOracle: A Cytoscape App for Covisualizing and Coanalyzing Post-Translational Modifications in Protein Interaction Networks.

    PubMed

    Tay, Aidan P; Pang, Chi Nam Ignatius; Winter, Daniel L; Wilkins, Marc R

    2017-04-06

    Post-translational modifications of proteins (PTMs) act as key regulators of protein activity and of protein-protein interactions (PPIs). To date, it has been difficult to comprehensively explore functional links between PTMs and PPIs. To address this, we developed PTMOracle, a Cytoscape app for coanalyzing PTMs within PPI networks. PTMOracle also allows extensive data to be integrated and coanalyzed with PPI networks, allowing the role of domains, motifs, and disordered regions to be considered. For proteins of interest, or a whole proteome, PTMOracle can generate network visualizations to reveal complex PTM-associated relationships. This is assisted by OraclePainter for coloring proteins by modifications, OracleTools for network analytics, and OracleResults for exploring tabulated findings. To illustrate the use of PTMOracle, we investigate PTM-associated relationships and their role in PPIs in four case studies. In the yeast interactome and its rich set of PTMs, we construct and explore histone-associated and domain-domain interaction networks and show how integrative approaches can predict kinases involved in phosphodegrons. In the human interactome, a phosphotyrosine-associated network is analyzed but highlights the sparse nature of human PPI networks and lack of PTM-associated data. PTMOracle is open source and available at the Cytoscape app store: http://apps.cytoscape.org/apps/ptmoracle .

  4. Arsenic affects expression and processing of amyloid precursor protein (APP) in primary neuronal cells overexpressing the Swedish mutation of human APP.

    PubMed

    Zarazúa, Sergio; Bürger, Susanne; Delgado, Juan M; Jiménez-Capdeville, Maria E; Schliebs, Reinhard

    2011-06-01

    Arsenic poisoning due to contaminated water and soil, mining waste, glass manufacture, select agrochemicals, as well as sea food, affects millions of people world wide. Recently, an involvement of arsenic in Alzheimer's disease (AD) has been hypothesized (Gong and O'Bryant, 2010). The present study stresses the hypothesis whether sodium arsenite, and its main metabolite, dimethylarsinic acid (DMA), may affect expression and processing of the amyloid precursor protein (APP), using the cholinergic cell line SN56.B5.G4 and primary neuronal cells overexpressing the Swedish mutation of APP, as experimental approaches. Exposure of cholinergic SN56.B5.G4 cells with either sodium arsenite or DMA decreased cell viability in a concentration- and exposure-time dependent manner, and affected the activities of the cholinergic enzymes acetylcholinesterase and choline acetyltransferase. Both sodium arsenite and DMA exposure of SN56.B5.G4 cells resulted in enhanced level of APP, and sAPP in the membrane and cytosolic fractions, respectively. To reveal any effect of arsenic on APP processing, the amounts of APP cleavage products, sAPPβ, and β-amyloid (Aβ) peptides, released into the culture medium of primary neuronal cells derived from transgenic Tg2576 mice, were assessed by ELISA. Following exposure of neuronal cells by sodium arsenite for 12h, the membrane-bound APP level was enhanced, the amount of sAPPβ released into the culture medium was slightly higher, while the levels of Aβ peptides in the culture medium were considerably lower as compared to that assayed in the absence of any drug. The sodium arsenite-induced reduction of Aβ formation suggests an inhibition of the APP γ-cleavage step by arsenite. In contrast, DMA exposure of neuronal cells considerably increased formation of Aβ and sAPPβ, accompanied by enhanced membrane APP level. The DMA-induced changes in APP processing may be the result of the enhanced APP expression. Alternatively, increased Aβ production

  5. Y682G Mutation of Amyloid Precursor Protein Promotes Endo-Lysosomal Dysfunction by Disrupting APP-SorLA Interaction.

    PubMed

    La Rosa, Luca Rosario; Perrone, Lorena; Nielsen, Morten Schallburg; Calissano, Pietro; Andersen, Olav Michael; Matrone, Carmela

    2015-01-01

    The intracellular transport and localization of amyloid precursor protein (APP) are critical determinants of APP processing and β-amyloid peptide production, thus crucially important for the pathophysiology of Alzheimer's disease (AD). Notably, the C-terminal Y682ENPTY687 domain of APP binds to specific adaptors controlling APP trafficking and sorting in neurons. Mutation on the Y682 residue to glycine (Y682G) leads to altered APP sorting in hippocampal neurons that favors its accumulation in intracellular compartments and the release of soluble APPα. Such alterations induce premature aging and learning and cognitive deficits in APP Y682G mutant mice (APP (YG/YG) ). Here, we report that Y682G mutation affects formation of the APP complex with sortilin-related receptor (SorLA), resulting in endo-lysosomal dysfunctions and neuronal degeneration. Moreover, disruption of the APP/SorLA complex changes the trafficking pathway of SorLA, with its consequent increase in secretion outside neurons. Mutations in the SorLA gene are a prognostic factor in AD, and changes in SorLA levels in cerebrospinal fluid are predictive of AD in humans. These results might open new possibilities in comprehending the role played by SorLA in its interaction with APP and in the progression of neuronal degeneration. In addition, they further underline the crucial role played by Y682 residue in controlling APP trafficking in neurons.

  6. The roles of amyloid precursor protein (APP) in neurogenesis: Implications to pathogenesis and therapy of Alzheimer disease.

    PubMed

    Zhou, Zhi-dong; Chan, Christine Hui-shan; Ma, Quan-hong; Xu, Xiao-hong; Xiao, Zhi-cheng; Tan, Eng-king

    2011-01-01

    The amyloid-beta (Aβ) peptide is the derivative of amyloid precursor protein (APP) generated through sequential proteolytic processing by β- and γ-secretases. Excessive accumulation of Aβ, the main constituent of amyloid plaques, has been implicated in the etiology of Alzheimer's disease (AD). It was found recently that the impairments of neurogenesis in brain were associated with the pathogenesis of AD. Furthermore recent findings implicated that APP could function to influence proliferation of neural progenitor cells (NPC) and might regulate transcriptional activity of various genes. Studies demonstrated that influence of neurogenesis by APP is conferred differently via its two separate domains, soluble secreted APPs (sAPPs, mainly sAPPα) and APP intracellular domain (AICD). The sAPPα was shown to be neuroprotective and important to neurogenesis, whereas AICD was found to negatively modulate neurogenesis. Furthermore, it was demonstrated recently that microRNA could function to regulate APP expression, APP processing, Aβ accumulation and subsequently influence neurotoxicity and neurogenesis related to APP, which was implicated to AD pathogenesis, especially for sporadic AD. Based on data accumulated, secretase balances were proposed. These secretase balances could influence the downstream balance related to regulation of neurogenesis by AICD and sAPPα as well as balance related to influence of neuron viability by Aβ and sAPPα. Disruption of these secretase balances could be culprits to AD onset.

  7. Opposite Dysregulation of Fragile-X Mental Retardation Protein and Heteronuclear Ribonucleoprotein C Protein Associates with Enhanced APP Translation in Alzheimer Disease.

    PubMed

    Borreca, Antonella; Gironi, Katia; Amadoro, Giusy; Ammassari-Teule, Martine

    2016-07-01

    Amyloid precursor protein (APP) is overexpressed in familiar and sporadic Alzheimer Disease (AD) patients suggesting that, in addition to abnormalities in APP cleavage, enhanced levels of APP full length might contribute to the pathology. Based on data showing that the two RNA binding proteins (RBPs), Fragile-X Mental Retardation Protein (FMRP) and heteronuclear Ribonucleoprotein C (hnRNP C), exert an opposite control on APP translation, we have analyzed whether expression and translation of these two RBPs vary in relation to changes in APP protein and mRNA levels in the AD brain at 1, 3, and 6 months of age. Here, we show that, as expected, human APP is overexpressed in hippocampal total extract from Tg2576 mice at all age points. APP overexpression, however, is not stable over time but reaches its maximal level in 1-month-old mutants in association with the stronger (i) reduction of FMRP and (ii) augmentation of hnRNP C. APP levels then decrease progressively as a function of age in close relationship with the gradual normalization of FMRP and hnRNP C levels. Consistent with the mouse data, expression of FMRP and hnRNP C are, respectively, decreased and increased in hippocampal synaptosomes from sporadic AD patients. Our findings identify two RBP targets that might be manipulated for reducing abnormally elevated levels of APP in the AD brain, with the hypothesis that acting upstream of amyloidogenic processing might contribute to attenuate the amyloid burden.

  8. Neuronal ELAVL proteins utilize AUF-1 as a co-partner to induce neuron-specific alternative splicing of APP

    PubMed Central

    Fragkouli, Apostolia; Koukouraki, Pelagia; Vlachos, Ioannis S.; Paraskevopoulou, Maria D.; Hatzigeorgiou, Artemis G.; Doxakis, Epaminondas

    2017-01-01

    Aβ peptide that accumulates in Alzheimer’s disease brain, derives from proteolytic processing of the amyloid precursor protein (APP) that exists in three main isoforms derived by alternative splicing. The isoform APP695, lacking exons 7 and 8, is predominately expressed in neurons and abnormal neuronal splicing of APP has been observed in the brain of patients with Alzheimer’s disease. Herein, we demonstrate that expression of the neuronal members of the ELAVL protein family (nELAVLs) correlate with APP695 levels in vitro and in vivo. Moreover, we provide evidence that nELAVLs regulate the production of APP695; by using a series of reporters we show that concurrent binding of nELAVLs to sequences located both upstream and downstream of exon 7 is required for its skipping, whereas nELAVL-binding to a highly conserved U-rich sequence upstream of exon 8, is sufficient for its exclusion. Finally, we report that nELAVLs block APP exon 7 or 8 definition by reducing the binding of the essential splicing factor U2AF65, an effect facilitated by the concurrent binding of AUF-1. Our study provides new insights into the regulation of APP pre-mRNA processing, supports the role for nELAVLs as neuron-specific splicing regulators and reveals a novel function of AUF1 in alternative splicing. PMID:28291226

  9. ApoER2 expression increases Aβ production while decreasing Amyloid Precursor Protein (APP) endocytosis: Possible role in the partitioning of APP into lipid rafts and in the regulation of γ-secretase activity

    PubMed Central

    Fuentealba, Rodrigo A; Barría, Maria Ines; Lee, Jiyeon; Cam, Judy; Araya, Claudia; Escudero, Claudia A; Inestrosa, Nibaldo C; Bronfman, Francisca C; Bu, Guojun; Marzolo, Maria-Paz

    2007-01-01

    Background The generation of the amyloid-β peptide (Aβ) through the proteolytic processing of the amyloid precursor protein (APP) is a central event in the pathogenesis of Alzheimer's disease (AD). Recent studies highlight APP endocytosis and localization to lipid rafts as important events favoring amyloidogenic processing. However, the precise mechanisms underlying these events are poorly understood. ApoER2 is a member of the low density lipoprotein receptor (LDL-R) family exhibiting slow endocytosis rate and a significant association with lipid rafts. Despite the important neurophysiological roles described for ApoER2, little is known regarding how ApoER2 regulates APP trafficking and processing. Results Here, we demonstrate that ApoER2 physically interacts and co-localizes with APP. Remarkably, we found that ApoER2 increases cell surface APP levels and APP association with lipid rafts. The increase of cell surface APP requires the presence of ApoER2 cytoplasmic domain and is a result of decreased APP internalization rate. Unexpectedly, ApoER2 expression correlated with a significant increase in Aβ production and reduced levels of APP-CTFs. The increased Aβ production was dependent on the integrity of the NPxY endocytosis motif of ApoER2. We also found that expression of ApoER2 increased APP association with lipid rafts and increased γ-secretase activity, both of which might contribute to increased Aβ production. Conclusion These findings show that ApoER2 negatively affects APP internalization. However, ApoER2 expression stimulates Aβ production by shifting the proportion of APP from the non-rafts to the raft membrane domains, thereby promoting β-secretase and γ-secretase mediated amyloidogenic processing and also by incrementing the activity of γ-secretase. PMID:17620134

  10. Two different immunostaining patterns of beta-amyloid precursor protein (APP) may distinguish traumatic from nontraumatic axonal injury.

    PubMed

    Hayashi, Takahito; Ago, Kazutoshi; Nakamae, Takuma; Higo, Eri; Ogata, Mamoru

    2015-09-01

    Immunostaining for beta-amyloid precursor protein (APP) is recognized as an effective tool for detecting traumatic axonal injury, but it also detects axonal injury due to ischemic or other metabolic causes. Previously, we reported two different patterns of APP staining: labeled axons oriented along with white matter bundles (pattern 1) and labeled axons scattered irregularly (pattern 2) (Hayashi et al. (Leg Med (Tokyo) 11:S171-173, 2009). In this study, we investigated whether these two patterns are consistent with patterns of trauma and hypoxic brain damage, respectively. Sections of the corpus callosum from 44 cases of blunt head injury and equivalent control tissue were immunostained for APP. APP was detected in injured axons such as axonal bulbs and varicose axons in 24 of the 44 cases of head injuries that also survived for three or more hours after injury. In 21 of the 24 APP-positive cases, pattern 1 alone was observed in 14 cases, pattern 2 alone was not observed in any cases, and both patterns 1 and 2 were detected in 7 cases. APP-labeled injured axons were detected in 3 of the 44 control cases, all of which were pattern 2. These results suggest that pattern 1 indicates traumatic axonal injury, while pattern 2 results from hypoxic insult. These patterns may be useful to differentiate between traumatic and nontraumatic axonal injuries.

  11. The kunitz protease inhibitor form of the amyloid precursor protein (KPI/APP) inhibits the proneuropeptide processing enzyme prohormone thiol protease (PTP). Colocalization of KPI/APP and PTP in secretory vesicles.

    PubMed

    Hook, V Y; Sei, C; Yasothornsrikul, S; Toneff, T; Kang, Y H; Efthimiopoulos, S; Robakis, N K; Van Nostrand, W

    1999-01-29

    Proteolytic processing of proenkephalin and proneuropeptides is required for the production of active neurotransmitters and peptide hormones. Variations in the extent of proenkephalin processing in vivo suggest involvement of endogenous protease inhibitors. This study demonstrates that "protease nexin 2 (PN2)," the secreted form of the kunitz protease inhibitor (KPI) of the amyloid precursor protein (APP), potently inhibited the proenkephalin processing enzyme known as prohormone thiol protease (PTP), with a Ki,app of 400 nM. Moreover, PTP and PN2 formed SDS-stable complexes that are typical of kunitz protease inhibitor interactions with target proteases. In vivo, KPI/APP (120 kDa), as well as a truncated form of KPI/APP that resembles PN2 in apparent molecular mass (110 kDa), were colocalized with PTP and (Met)enkephalin in secretory vesicles of adrenal medulla (chromaffin granules). KPI/APP (110-120 kDa) was also detected in pituitary secretory vesicles that contain PTP. In chromaffin cells, calcium-dependent secretion of KPI/APP with PTP and (Met)enkephalin demonstrated the colocalization of these components in functional secretory vesicles. These results suggest a role for KPI/APP inhibition of PTP in regulated secretory vesicles. In addition, these results are the first to identify an endogenous protease target of KPI/APP, which is developmentally regulated in aging and Alzheimer's disease.

  12. A Synthetic Peptide with the Putative Iron Binding Motif of Amyloid Precursor Protein (APP) Does Not Catalytically Oxidize Iron

    PubMed Central

    Ebrahimi, Kourosh Honarmand; Hagedoorn, Peter-Leon; Hagen, Wilfred R.

    2012-01-01

    The β-amyloid precursor protein (APP), which is a key player in Alzheimer's disease, was recently reported to possess an Fe(II) binding site within its E2 domain which exhibits ferroxidase activity [Duce et al. 2010, Cell 142: 857]. The putative ligands of this site were compared to those in the ferroxidase site of ferritin. The activity was indirectly measured using transferrin, which scavenges the Fe(III) product of the reaction. A 22-residue synthetic peptide, named FD1, with the putative ferroxidase site of APP, and the E2 domain of APP were each reported to exhibit 40% of the ferroxidase activity of APP and of ceruloplasmin. It was also claimed that the ferroxidase activity of APP is inhibited by Zn(II) just as in ferritin. We measured the ferroxidase activity indirectly (i) by the incorporation of the Fe(III) product of the ferroxidase reaction into transferrin and directly (ii) by monitoring consumption of the substrate molecular oxygen. The results with the FD1 peptide were compared to the established ferroxidase activities of human H-chain ferritin and of ceruloplasmin. For FD1 we observed no activity above the background of non-enzymatic Fe(II) oxidation by molecular oxygen. Zn(II) binds to transferrin and diminishes its Fe(III) incorporation capacity and rate but it does not specifically bind to a putative ferroxidase site of FD1. Based on these results, and on comparison of the putative ligands of the ferroxidase site of APP with those of ferritin, we conclude that the previously reported results for ferroxidase activity of FD1 and – by implication – of APP should be re-evaluated. PMID:22916096

  13. The APP-Interacting Protein FE65 is Required for Hippocampus-Dependent Learning and Long-Term Potentiation

    ERIC Educational Resources Information Center

    Wang, Yan; Zhang, Ming; Moon, Changjong; Hu, Qubai; Wang, Baiping; Martin, George; Sun, Zhongsheng; Wang, Hongbing

    2009-01-01

    FE65 is expressed predominantly in the brain and interacts with the C-terminal domain of [beta]-amyloid precursor protein (APP). We examined hippocampus-dependent memory and in vivo long-term potentiation (LTP) at the CA1 synapses with isoform-specific FE65 knockout (p97FE65[superscript -/-]) mice. When examined using the Morris water maze,…

  14. Age and gene overexpression interact to abolish nesting behavior in Tg2576 amyloid precursor protein (APP) mice.

    PubMed

    Wesson, Daniel W; Wilson, Donald A

    2011-01-01

    Elucidating the modulators of social behavioral is important in understanding the neural basis of behavior and in developing methods to enhance behavior in cases of disorder. The work here stems from the observation that the Alzheimer's disease mouse model Tg2576, overexpressing human mutations of the amyloid-β precursor protein (APP), fails to construct nests when supplied paper towels in their home cages. Experiments using commercially available cotton nesting material found similar results. Additional experiments revealed that the genotype effect is progressively modulated by age in APP mice but not their WT counterparts. There was no effect of sex on nesting behavior in any group. Finally, this effect was independent of ambient temperature - even when subjected to a cold environment, APP mice fail to build nests whereas WT mice do. These results suggest that the APP gene plays a role in affiliative behaviors and are discussed in relation to disorders characteristic of mutations in the APP gene and in affective dysfunction, including Alzheimer's disease.

  15. Holo-APP and G-protein-mediated signaling are required for sAPPα-induced activation of the Akt survival pathway

    PubMed Central

    Milosch, N; Tanriöver, G; Kundu, A; Rami, A; François, J-C; Baumkötter, F; Weyer, S W; Samanta, A; Jäschke, A; Brod, F; Buchholz, C J; Kins, S; Behl, C; Müller, U C; Kögel, D

    2014-01-01

    Accumulating evidence indicates that loss of physiologic amyloid precursor protein (APP) function leads to reduced neuronal plasticity, diminished synaptic signaling and enhanced susceptibility of neurons to cellular stress during brain aging. Here we investigated the neuroprotective function of the soluble APP ectodomain sAPPα (soluble APPα), which is generated by cleavage of APP by α-secretase along the non-amyloidogenic pathway. Recombinant sAPPα protected primary hippocampal neurons and SH-SY5Y neuroblastoma cells from cell death induced by trophic factor deprivation. We show that this protective effect is abrogated in neurons from APP-knockout animals and APP-depleted SH-SY5Y cells, but not in APP-like protein 1- and 2- (APLP1 and APLP2) depleted cells, indicating that expression of membrane-bound holo-APP is required for sAPPα-dependent neuroprotection. Trophic factor deprivation diminished the activity of the Akt survival pathway. Strikingly, both recombinant sAPPα and the APP-E1 domain were able to stimulate Akt activity in wild-type (wt) fibroblasts, SH-SY5Y cells and neurons, but failed to rescue in APP-deficient neurons or fibroblasts. The ADAM10 (a disintegrin and metalloproteinase domain-containing protein 10) inhibitor GI254023X exacerbated neuron death in organotypic (hippocampal) slice cultures of wt mice subjected to trophic factor and glucose deprivation. This cell death-enhancing effect of GI254023X could be completely rescued by applying exogenous sAPPα. Interestingly, sAPPα-dependent Akt induction was unaffected in neurons of APP-ΔCT15 mice that lack the C-terminal YENPTY motif of the APP intracellular region. In contrast, sAPPα-dependent rescue of Akt activation was completely abolished in APP mutant cells lacking the G-protein interaction motif located in the APP C-terminus and by blocking G-protein-dependent signaling with pertussis toxin. Collectively, our data provide new mechanistic insights into the physiologic role of APP in

  16. Holo-APP and G-protein-mediated signaling are required for sAPPα-induced activation of the Akt survival pathway.

    PubMed

    Milosch, N; Tanriöver, G; Kundu, A; Rami, A; François, J-C; Baumkötter, F; Weyer, S W; Samanta, A; Jäschke, A; Brod, F; Buchholz, C J; Kins, S; Behl, C; Müller, U C; Kögel, D

    2014-08-28

    Accumulating evidence indicates that loss of physiologic amyloid precursor protein (APP) function leads to reduced neuronal plasticity, diminished synaptic signaling and enhanced susceptibility of neurons to cellular stress during brain aging. Here we investigated the neuroprotective function of the soluble APP ectodomain sAPPα (soluble APPα), which is generated by cleavage of APP by α-secretase along the non-amyloidogenic pathway. Recombinant sAPPα protected primary hippocampal neurons and SH-SY5Y neuroblastoma cells from cell death induced by trophic factor deprivation. We show that this protective effect is abrogated in neurons from APP-knockout animals and APP-depleted SH-SY5Y cells, but not in APP-like protein 1- and 2- (APLP1 and APLP2) depleted cells, indicating that expression of membrane-bound holo-APP is required for sAPPα-dependent neuroprotection. Trophic factor deprivation diminished the activity of the Akt survival pathway. Strikingly, both recombinant sAPPα and the APP-E1 domain were able to stimulate Akt activity in wild-type (wt) fibroblasts, SH-SY5Y cells and neurons, but failed to rescue in APP-deficient neurons or fibroblasts. The ADAM10 (a disintegrin and metalloproteinase domain-containing protein 10) inhibitor GI254023X exacerbated neuron death in organotypic (hippocampal) slice cultures of wt mice subjected to trophic factor and glucose deprivation. This cell death-enhancing effect of GI254023X could be completely rescued by applying exogenous sAPPα. Interestingly, sAPPα-dependent Akt induction was unaffected in neurons of APP-ΔCT15 mice that lack the C-terminal YENPTY motif of the APP intracellular region. In contrast, sAPPα-dependent rescue of Akt activation was completely abolished in APP mutant cells lacking the G-protein interaction motif located in the APP C-terminus and by blocking G-protein-dependent signaling with pertussis toxin. Collectively, our data provide new mechanistic insights into the physiologic role of APP in

  17. Fuzzy logic for personalized healthcare and diagnostics: FuzzyApp--a fuzzy logic based allergen-protein predictor.

    PubMed

    Saravanan, Vijayakumar; Lakshmi, P T V

    2014-09-01

    The path to personalized medicine demands the use of new and customized biopharmaceutical products containing modified proteins. Hence, assessment of these products for allergenicity becomes mandatory before they are introduced as therapeutics. Despite the availability of different tools to predict the allergenicity of proteins, it remains challenging to predict the allergens and nonallergens, when they share significant sequence similarity with known nonallergens and allergens, respectively. Hence, we propose "FuzzyApp," a novel fuzzy rule based system to evaluate the quality of the query protein to be an allergen. It measures the allergenicity of the protein based on the fuzzy IF-THEN rules derived from five different modules. On various datasets, FuzzyApp outperformed other existing methods and retained balance between sensitivity and specificity, with positive Mathew's correlation coefficient. The high specificity of allergen-like putative nonallergens (APN) revealed the FuzzyApp's capability in distinguishing the APN from allergens. In addition, the error analysis and whole proteome dataset analysis suggest the efficiency and consistency of the proposed method. Further, FuzzyApp predicted the Tropomyosin from various allergenic and nonallergenic sources accurately. The web service created allows batch sequence submission, and outputs the result as readable sentences rather than values alone, which assists the user in understanding why and what features are responsible for the prediction. FuzzyApp is implemented using PERL CGI and is freely accessible at http://fuzzyapp.bicpu.edu.in/predict.php . We suggest the use of Fuzzy logic has much potential in biomarker and personalized medicine research to enhance predictive capabilities of post-genomics diagnostics.

  18. Duplication of amyloid precursor protein (APP), but not prion protein (PRNP) gene is a significant cause of early onset dementia in a large UK series

    PubMed Central

    McNaughton, Daniel; Knight, William; Guerreiro, Rita; Ryan, Natalie; Lowe, Jessica; Poulter, Mark; Nicholl, David J.; Hardy, John; Revesz, Tamas; Lowe, James; Rossor, Martin; Collinge, John; Mead, Simon

    2012-01-01

    Amyloid precursor protein gene (APP) duplications have been identified in screens of selected probands with early onset familial Alzheimer's disease (FAD). A causal role for copy number variation (CNV) in the prion protein gene (PRNP) in prion dementias is not known. We aimed to determine the prevalence of copy number variation in APP and PRNP in a large referral series, test a screening method for detection of the same, and expand knowledge of clinical phenotype. We used a 3-tiered screening assay for APP and PRNP duplication (exonic real-time quantitative polymerase chain reaction [exon-qPCR], fluorescent microsatellite quantitative PCR [fm-q-PCR], and Illumina array [Illumina Inc., San Diego, CA, USA]) for analysis of a heterogeneous referral series comprising 1531 probands. Five of 1531 probands screened showed APP duplication, a similar prevalence to APP missense mutation. Real-time quantitative PCR and fluorescent microsatellite quantitative PCR were similar individually but are theoretically complementary; we used Illumina arrays as our reference assay. Two of 5 probands were from an autosomal dominant early onset Alzheimer's disease (familial Alzheimer's disease) pedigree. One extensive, noncontiguous duplication on chromosome 21 was consistent with an unbalanced translocation not including the Down's syndrome critical region. Seizures were prominent in the other typical APP duplications. A range of imaging, neuropsychological, cerebrospinal fluid, and pathological findings are reported that extend the known phenotype. APP but not PRNP duplication is a significant cause of early onset dementia in the UK. The recognized phenotype may be expanded to include the possibility of early seizures and apparently sporadic disease which, in part, may be due to different mutational mechanisms. The pros and cons of our screening method are discussed. PMID:21193246

  19. A macromolecular complex involving the amyloid precursor protein (APP) and the cytosolic adapter FE65 is a negative regulator of axon branching

    PubMed Central

    Ikin, Annat F.; Sabo, Shasta L.; Lanier, Lorene M.; Buxbaum, Joseph D.

    2011-01-01

    Several studies suggest a role for the amyloid precursor protein (APP) in neurite outgrowth and synaptogenesis, but the downstream interactions that mediate the function of APP during neuron development are unknown. By introducing interaction-deficient FE65 into cultured hippocampal neurons using adenovirus, we show that a complex including APP, FE65 and an additional protein is involved in neurite outgrowth at early stages of neuronal development. Both FE65 that is unable to interact with APP (PID2 mutants) or a WW mutant increased axon branching. Although the FE65 mutants did not affect total neurite output, both mutants decreased axon segment length, consistent with an overall slowing of axonal growth cones. FE65 mutants did not alter the localization of either APP or FE65 in axonal growth cones, suggesting that the effects on neurite outgrowth are achieved by alterations in local complex formation within the axonal growth cone. PMID:17383198

  20. Genomic mosaicism with increased amyloid precursor protein (APP) gene copy number in single neurons from sporadic Alzheimer's disease brains

    PubMed Central

    Bushman, Diane M; Kaeser, Gwendolyn E; Siddoway, Benjamin; Westra, Jurgen W; Rivera, Richard R; Rehen, Stevens K; Yung, Yun C; Chun, Jerold

    2015-01-01

    Previous reports have shown that individual neurons of the brain can display somatic genomic mosaicism of unknown function. In this study, we report altered genomic mosaicism in single, sporadic Alzheimer's disease (AD) neurons characterized by increases in DNA content and amyloid precursor protein (APP) gene copy number. AD cortical nuclei displayed large variability with average DNA content increases of ∼8% over non-diseased controls that were unrelated to trisomy 21. Two independent single-cell copy number analyses identified amplifications at the APP locus. The use of single-cell qPCR identified up to 12 copies of APP in sampled neurons. Peptide nucleic acid (PNA) probes targeting APP, combined with super-resolution microscopy detected primarily single fluorescent signals of variable intensity that paralleled single-cell qPCR analyses. These data identify somatic genomic changes in single neurons, affecting known and unknown loci, which are increased in sporadic AD, and further indicate functionality for genomic mosaicism in the CNS. DOI: http://dx.doi.org/10.7554/eLife.05116.001 PMID:25650802

  1. Phosphorylation of APP-CTF-AICD domains and interaction with adaptor proteins: signal transduction and/or transcriptional role--relevance for Alzheimer pathology.

    PubMed

    Schettini, Gennaro; Govoni, Stefano; Racchi, Marco; Rodriguez, Guido

    2010-12-01

    In recent decades, the study of the amyloid precursor protein (APP) and of its proteolytic products carboxy terminal fragment (CTF), APP intracellular C-terminal domain (AICD) and amyloid beta has been mostly focussed on the role of APP as a producer of the toxic amyloid beta peptide. Here, we reconsider the role of APP suggesting, in a provocative way, the protein as a central player in a putative signalling pathway. We highlight the presence in the cytosolic tail of APP of the YENPTY motif which is typical of tyrosine kinase receptors, the phosphorylation of the tyrosine, serine and threonine residues, the kinases involved and the interaction with intracellular adaptor proteins. In particular, we examine the interaction with Shc and Grb2 regulators, which through the activation of Ras proteins elicit downstream signalling events such as the MAPK pathway. The review also addresses the interaction of APP, CTFs and AICD with other adaptor proteins and in particular with Fe65 for nuclear transcriptional activity and the importance of phosphorylation for sorting the secretases involved in the amyloidogenic or non-amyloidogenic pathways. We provide a novel perspective on Alzheimer's disease pathogenesis, focussing on the perturbation of the physiological activities of APP-CTFs and AICD as an alternative perspective from that which normally focuses on the accumulation of neurotoxic proteolytic fragments.

  2. Phase retrieval in protein crystallography.

    PubMed

    Liu, Zhong Chuan; Xu, Rui; Dong, Yu Hui

    2012-03-01

    Solution of the phase problem is central to crystallographic structure determination. An oversampling method is proposed, based on the hybrid input-output algorithm (HIO) [Fienup (1982). Appl. Opt. 21, 2758-2769], to retrieve the phases of reflections in crystallography. This method can extend low-resolution structures to higher resolution for structure determination of proteins without additional sample preparation. The method requires an envelope of the protein which divides a unit cell into the density region where the proteins are located and the non-density region occupied by solvents. After a few hundred to a few thousand iterations, the correct phases and density maps are recovered. The method has been used successfully in several cases to retrieve the phases from the experimental X-ray diffraction data and the envelopes of proteins constructed from structure files downloaded from the Protein Data Bank. It is hoped that this method will greatly facilitate the ab initio structure determination of proteins.

  3. Alternative Selection of β-Site APP-Cleaving Enzyme 1 (BACE1) Cleavage Sites in Amyloid β-Protein Precursor (APP) Harboring Protective and Pathogenic Mutations within the Aβ Sequence.

    PubMed

    Kimura, Ayano; Hata, Saori; Suzuki, Toshiharu

    2016-11-11

    β-Site APP-cleaving enzyme 1 (BACE1) cleaves amyloid β-protein precursor (APP) at the bond between Met(671) and Asp(672) (β-site) to generate the carboxyl-terminal fragment (CTFβ/C99). BACE1 also cleaves APP at another bond between Thr(681) and Gln(682) (β'-site), yielding CTFβ'/C89. Cleavage of CTFβ/C99 by γ-secretase generates Aβ(1-XX), whereas cleavage of CTFβ'/C89 generates Aβ(11-XX). Thus, β'-site cleavage by BACE1 is amyloidolytic rather than amyloidogenic. β' cleavage of mouse APP is more common than the corresponding cleavage of human APP. We found that the H684R substitution within human Aβ, which replaces the histidine in the human protein with the arginine found at the corresponding position in mouse, facilitated β' cleavage irrespective of the species origin of BACE1, thereby significantly increasing the level of Aβ(11-XX) and decreasing the level of Aβ(1-XX). Thus, amino acid substitutions within the Aβ sequence influenced the selectivity of alternative β- or β'-site cleavage of APP by BACE1. In familial Alzheimer's disease (FAD), the APP gene harbors pathogenic variations such as the Swedish (K670N/M671L), Leuven (E682K), and A673V mutations, all of which decrease Aβ(11-40) generation, whereas the protective Icelandic mutation (A673T) increases generation of Aβ(11-40). Thus, A673T promotes β' cleavage of APP and protects subjects against AD. In addition, CTFβ/C99 was cleaved by excess BACE1 activity to generate CTFβ'/C89, followed by Aβ(11-40), even if APP harbored pathogenic mutations. The resultant Aβ(11-40) was more metabolically labile in vivo than Aβ(1-40). Our analysis suggests that some FAD mutations in APP are amyloidogenic and/or amyloidolytic via selection of alternative BACE1 cleavage sites.

  4. Nucleofection of Rat Pheochromocytoma PC-12 Cells with Human Mutated Beta-Amyloid Precursor Protein Gene (APP-sw) Leads to Reduced Viability, Autophagy-Like Process, and Increased Expression and Secretion of Beta Amyloid

    PubMed Central

    Pająk, Beata; Kania, Elżbieta

    2015-01-01

    Pheochromocytoma PC-12 cells are immune to physiological stimuli directed to evoke programmed cell death. Besides, metabolic inhibitors are incapable of sensitizing PC-12 cells to extrinsic or intrinsic apoptosis unless they are used in toxic concentrations. Surprisingly, these cells become receptive to cell deletion after human APP-sw gene expression. We observed reduced cell viability in GFP vector + APP-sw-nucleofected cells (drop by 36%) but not in GFP vector − or GFP vector + APP-wt-nucleofected cells. Lower viability was accompanied by higher expression of Aβ 1-16 and elevated secretion of Aβ 1-40 (in average 53.58 pg/mL). At the ultrastructural level autophagy-like process was demonstrated to occur in APP-sw-nucleofected cells with numerous autophagosomes and multivesicular bodies but without autolysosomes. Human APP-sw gene is harmful to PC-12 cells and cells are additionally driven to incomplete autophagy-like process. When stimulated by TRAIL or nystatin, CLU protein expression accompanies early phase of autophagy. PMID:25821818

  5. Mitochondrial dysfunction in a transgenic mouse model expressing human amyloid precursor protein (APP) with the Arctic mutation.

    PubMed

    Rönnbäck, Annica; Pavlov, Pavel F; Mansory, Mansorah; Gonze, Prisca; Marlière, Nicolas; Winblad, Bengt; Graff, Caroline; Behbahani, Homira

    2016-02-01

    Accumulation of amyloid β-peptide (Aβ) in the brain is an important event in the pathogenesis of Alzheimer disease. We have used a transgenic mouse model expressing human amyloid precursor protein (APP) with the Arctic mutation to investigate whether Aβ deposition is correlated with mitochondrial functions in these animals. We found evidence of mitochondrial dysfunction (i.e., decreased mitochondrial membrane potential, increased production of reactive oxygen species and oxidative DNA damage) at 6 months of age, when the mice showed very mild Aβ deposition. More pronounced mitochondrial abnormalities were present in 24-month-old TgAPParc mice with more extensive Aβ pathology. This study demonstrates for the first time mitochondrial dysfunction in transgenic mice with a mutation within the Aβ peptide (the Arctic APP mutation), and confirms previous studies suggesting that mitochondrial dysfunction and oxidative stress is an early event in the pathogenesis of Alzheimer disease. This study demonstrates mitochondrial dysfunction in transgenic mice with a mutation within the amyloid beta (Aβ) peptide (the Arctic amyloid precursor protein (APP) mutation). We found evidence of mitochondrial dysfunction (i.e. decreased mitochondrial membrane potential (MMP), increased production of reactive oxygen species (ROS) and oxidative DNA damage) at 6 months of age, when very mild Aβ deposition is present in the mice. Also, the cytochrome c (COX) activity was significantly decreased in mitochondria from transgenic mice at 24 months of age.

  6. Impaired theta-gamma coupling in APP-deficient mice

    PubMed Central

    Zhang, Xiaomin; Zhong, Wewei; Brankačk, Jurij; Weyer, Sascha W.; Müller, Ulrike C.; Tort, Adriano B. L.; Draguhn, Andreas

    2016-01-01

    Amyloid precursor protein (APP) is critically involved in the pathophysiology of Alzheimer’s disease, but its physiological functions remain elusive. Importantly, APP knockout (APP-KO) mice exhibit cognitive deficits, suggesting that APP plays a role at the neuronal network level. To investigate this possibility, we recorded local field potentials (LFPs) from the posterior parietal cortex, dorsal hippocampus and lateral prefrontal cortex of freely moving APP-KO mice. Spectral analyses showed that network oscillations within the theta- and gamma-frequency bands were not different between APP-KO and wild-type mice. Surprisingly, however, while gamma amplitude coupled to theta phase in all recorded regions of wild-type animals, in APP-KO mice theta-gamma coupling was strongly diminished in recordings from the parietal cortex and hippocampus, but not in LFPs recorded from the prefrontal cortex. Thus, lack of APP reduces oscillatory coupling in LFP recordings from specific brain regions, despite not affecting the amplitude of the oscillations. Together, our findings reveal reduced cross-frequency coupling as a functional marker of APP deficiency at the network level. PMID:26905287

  7. Ablation of Prion Protein in Wild Type Human Amyloid Precursor Protein (APP) Transgenic Mice Does Not Alter The Proteolysis of APP, Levels of Amyloid-β or Pathologic Phenotype

    PubMed Central

    Baybutt, Herbert; Diack, Abigail B.; Kellett, Katherine A. B.; Piccardo, Pedro; Manson, Jean C.

    2016-01-01

    The cellular prion protein (PrPC) has been proposed to play an important role in the pathogenesis of Alzheimer’s disease. In cellular models PrPC inhibited the action of the β-secretase BACE1 on wild type amyloid precursor protein resulting in a reduction in amyloid-β (Aβ) peptides. Here we have assessed the effect of genetic ablation of PrPC in transgenic mice expressing human wild type amyloid precursor protein (line I5). Deletion of PrPC had no effect on the α- and β-secretase proteolysis of the amyloid precursor protein (APP) nor on the amount of Aβ38, Aβ40 or Aβ42 in the brains of the mice. In addition, ablation of PrPC did not alter Aβ deposition or histopathology phenotype in this transgenic model. Thus using this transgenic model we could not provide evidence to support the hypothesis that PrPC regulates Aβ production. PMID:27447728

  8. c-Jun N-terminal Kinase (JNK) induces phosphorylation of amyloid precursor protein (APP) at Thr668, in okadaic acid-induced neurodegeneration

    PubMed Central

    Ahn, Ji-Hwan; So, Sang-Pil; Kim, Na-Young; Kim, Hyun-Ju; Yoon, Seung-Yong; Kim, Dong-Hou

    2016-01-01

    Several lines of evidence have revealed that phosphorylation of amyloid precursor protein (APP) at Thr668 is involved in the pathogenesis of Alzheimer’s disease (AD). Okadaic acid (OA), a protein phosphatase-2A inhibitor, has been used in AD research models to increase tau phosphorylation and induce neuronal death. We previously showed that OA increased levels of APP and induced accumulation of APP in axonal swellings. In this study, we found that in OA-treated neurons, phosphorylation of APP at Thr668 increased and accumulated in axonal swellings by c-jun N-terminal kinase (JNK), and not by Cdk5 or ERK/MAPK. These results suggest that JNK may be one of therapeutic targets for the treatment of AD. [BMB Reports 2016; 49(7): 376-381] PMID:26839154

  9. Neurons generated from APP/APLP1/APLP2 triple knockout embryonic stem cells behave normally in vitro and in vivo: lack of evidence for a cell autonomous role of the amyloid precursor protein in neuronal differentiation.

    PubMed

    Bergmans, Bruno A; Shariati, S Ali M; Habets, Ron L P; Verstreken, Patrik; Schoonjans, Luc; Müller, Ulrike; Dotti, Carlos G; De Strooper, Bart

    2010-03-31

    Alzheimer's disease amyloid precursor protein (APP) has been implicated in many neurobiologic processes, but supporting evidence remains indirect. Studies are confounded by the existence of two partially redundant APP homologues, APLP1 and APLP2. APP/APLP1/APLP2 triple knockout (APP tKO) mice display cobblestone lissencephaly and are perinatally lethal. To circumvent this problem, we generated APP triple knockout embryonic stem (ES) cells and differentiated these to APP triple knockout neurons in vitro and in vivo. In comparison with wild-type (WT) ES cell-derived neurons, APP tKO neurons formed equally pure neuronal cultures, had unaltered in vitro migratory capacities, had a similar acquisition of polarity, and were capable of extending long neurites and forming active excitatory synapses. These data were confirmed in vivo in chimeric mice with APP tKO neurons expressing the enhanced green fluorescent protein (eGFP) present in a WT background brain. The results suggest that the loss of the APP family of proteins has no major effect on these critical neuronal processes and that the apparent multitude of functions in which APP has been implicated might be characterized by molecular redundancy. Our stem cell culture provides an excellent tool to circumvent the problem of lack of viability of APP/APLP triple knockout mice and will help to explore the function of this intriguing protein further in vitro and in vivo.

  10. Palmitoylated APP Forms Dimers, Cleaved by BACE1.

    PubMed

    Bhattacharyya, Raja; Fenn, Rebecca H; Barren, Cory; Tanzi, Rudolph E; Kovacs, Dora M

    2016-01-01

    A major rate-limiting step for Aβ generation and deposition in Alzheimer's disease brains is BACE1-mediated cleavage (β-cleavage) of the amyloid precursor protein (APP). We previously reported that APP undergoes palmitoylation at two cysteine residues (Cys186 and Cys187) in the E1-ectodomain. 8-10% of total APP is palmitoylated in vitro and in vivo. Palmitoylated APP (palAPP) shows greater preference for β-cleavage than total APP in detergent resistant lipid rafts. Protein palmitoylation is known to promote protein dimerization. Since dimerization of APP at its E1-ectodomain results in elevated BACE1-mediated cleavage of APP, we have now investigated whether palmitoylation of APP affects its dimerization and whether this leads to elevated β-cleavage of the protein. Here we report that over 90% of palAPP is dimerized while only ~20% of total APP forms dimers. PalAPP-dimers are predominantly cis-oriented while total APP dimerizes in both cis- and trans-orientation. PalAPP forms dimers 4.5-times more efficiently than total APP. Overexpression of the palmitoylating enzymes DHHC7 and DHHC21 that increase palAPP levels and Aβ release, also increased APP dimerization in cells. Conversely, inhibition of APP palmitoylation by pharmacological inhibitors reduced APP-dimerization in coimmunoprecipitation and FLIM/FRET assays. Finally, in vitro BACE1-activity assays demonstrate that palmitoylation-dependent dimerization of APP promotes β-cleavage of APP in lipid-rich detergent resistant cell membranes (DRMs), when compared to total APP. Most importantly, generation of sAPPβ-sAPPβ dimers is dependent on APP-palmitoylation while total sAPPβ generation is not. Since BACE1 shows preference for palAPP dimers over total APP, palAPP dimers may serve as novel targets for effective β-cleavage inhibitors of APP as opposed to BACE1 inhibitors.

  11. Palmitoylated APP Forms Dimers, Cleaved by BACE1

    PubMed Central

    Fenn, Rebecca H.; Barren, Cory; Tanzi, Rudolph E.; Kovacs, Dora M.

    2016-01-01

    A major rate-limiting step for Aβ generation and deposition in Alzheimer’s disease brains is BACE1-mediated cleavage (β-cleavage) of the amyloid precursor protein (APP). We previously reported that APP undergoes palmitoylation at two cysteine residues (Cys186 and Cys187) in the E1-ectodomain. 8–10% of total APP is palmitoylated in vitro and in vivo. Palmitoylated APP (palAPP) shows greater preference for β-cleavage than total APP in detergent resistant lipid rafts. Protein palmitoylation is known to promote protein dimerization. Since dimerization of APP at its E1-ectodomain results in elevated BACE1-mediated cleavage of APP, we have now investigated whether palmitoylation of APP affects its dimerization and whether this leads to elevated β-cleavage of the protein. Here we report that over 90% of palAPP is dimerized while only ~20% of total APP forms dimers. PalAPP-dimers are predominantly cis-oriented while total APP dimerizes in both cis- and trans-orientation. PalAPP forms dimers 4.5-times more efficiently than total APP. Overexpression of the palmitoylating enzymes DHHC7 and DHHC21 that increase palAPP levels and Aβ release, also increased APP dimerization in cells. Conversely, inhibition of APP palmitoylation by pharmacological inhibitors reduced APP-dimerization in coimmunoprecipitation and FLIM/FRET assays. Finally, in vitro BACE1-activity assays demonstrate that palmitoylation-dependent dimerization of APP promotes β-cleavage of APP in lipid-rich detergent resistant cell membranes (DRMs), when compared to total APP. Most importantly, generation of sAPPβ-sAPPβ dimers is dependent on APP-palmitoylation while total sAPPβ generation is not. Since BACE1 shows preference for palAPP dimers over total APP, palAPP dimers may serve as novel targets for effective β-cleavage inhibitors of APP as opposed to BACE1 inhibitors. PMID:27875558

  12. Amyloid Precursor Protein (APP) May Act as a Substrate and a Recognition Unit for CRL4CRBN and Stub1 E3 Ligases Facilitating Ubiquitination of Proteins Involved in Presynaptic Functions and Neurodegeneration.

    PubMed

    Del Prete, Dolores; Rice, Richard C; Rajadhyaksha, Anjali M; D'Adamio, Luciano

    2016-08-12

    The amyloid precursor protein (APP), whose mutations cause Alzheimer disease, plays an important in vivo role and facilitates transmitter release. Because the APP cytosolic region (ACR) is essential for these functions, we have characterized its brain interactome. We found that the ACR interacts with proteins that regulate the ubiquitin-proteasome system, predominantly with the E3 ubiquitin-protein ligases Stub1, which binds the NH2 terminus of the ACR, and CRL4(CRBN), which is formed by Cul4a/b, Ddb1, and Crbn, and interacts with the COOH terminus of the ACR via Crbn. APP shares essential functions with APP-like protein-2 (APLP2) but not APP-like protein-1 (APLP1). Noteworthy, APLP2, but not APLP1, interacts with Stub1 and CRL4(CRBN), pointing to a functional pathway shared only by APP and APLP2. In vitro ubiquitination/ubiquitome analysis indicates that these E3 ligases are enzymatically active and ubiquitinate the ACR residues Lys(649/650/651/676/688) Deletion of Crbn reduces ubiquitination of Lys(676) suggesting that Lys(676) is physiologically ubiquitinated by CRL4(CRBN) The ACR facilitated in vitro ubiquitination of presynaptic proteins that regulate exocytosis, suggesting a mechanism by which APP tunes transmitter release. Other dementia-related proteins, namely Tau and apoE, interact with and are ubiquitinated via the ACR in vitro This, and the evidence that CRBN and CUL4B are linked to intellectual disability, prompts us to hypothesize a pathogenic mechanism, in which APP acts as a modulator of E3 ubiquitin-protein ligase(s), shared by distinct neuronal disorders. The well described accumulation of ubiquitinated protein inclusions in neurodegenerative diseases and the link between the ubiquitin-proteasome system and neurodegeneration make this concept plausible.

  13. Breaking the phase ambiguities arising from anomalous scattering technique by the direct method - applied to a known protein structure

    NASA Astrophysics Data System (ADS)

    Fan, Hai-fu; Gu, Yuan-xin; Han, Fu-son

    1985-01-01

    The method proposed by Fan et al. has been applied to the discrimination of phase doublets arising from the experimental OAS (one-wave-length anomalous scattering) data of the Hg-derivative of APP. Encouraging result was obtained which showed that the method is hopeful to be an important tool in the structure analysis of protein crystals.

  14. The N-terminal fragment of the β-amyloid precursor protein of Alzheimer's disease (N-APP) binds to phosphoinositide-rich domains on the surface of hippocampal neurons.

    PubMed

    Dawkins, Edgar; Gasperini, Robert; Hu, Yanling; Cui, Hao; Vincent, Adele J; Bolós, Marta; Young, Kaylene M; Foa, Lisa; Small, David H

    2014-11-01

    The function of the β-amyloid precursor protein (APP) of Alzheimer's disease is poorly understood. The secreted ectodomain fragment of APP (sAPPα) can be readily cleaved to produce a small N-terminal fragment (N-APP) that contains heparin-binding and metal-binding domains and that has been found to have biological activity. In the present study, we examined whether N-APP can bind to lipids. We found that N-APP binds selectively to phosphoinositides (PIPs) but poorly to most other lipids. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 )-rich microdomains were identified on the extracellular surface of neurons and glia in primary hippocampal cultures. N-APP bound to neurons and colocalized with PIPs on the cell surface. Furthermore, the binding of N-APP to neurons increased the level of cell-surface PI(4,5)P2 and phosphatidylinositol 3,4,5-trisphosphate. However, PIPs were not the principal cell-surface binding site for N-APP, because N-APP binding to neurons was not inhibited by a short-acyl-chain PIP analogue, and N-APP did not bind to glial cells which also possessed PI(4,5)P2 on the cell surface. The data are explained by a model in which N-APP binds to two distinct components on neurons, one of which is an unidentified receptor and the second of which is a PIP lipid, which binds more weakly to a distinct site within N-APP. Our data provide further support for the idea that N-APP may be an important mediator of APP's biological activity.

  15. RCSB PDB Mobile: iOS and Android mobile apps to provide data access and visualization to the RCSB Protein Data Bank

    PubMed Central

    Quinn, Gregory B.; Bi, Chunxiao; Christie, Cole H.; Pang, Kyle; Prlić, Andreas; Nakane, Takanori; Zardecki, Christine; Voigt, Maria; Berman, Helen M.; Rose, Peter W.

    2015-01-01

    Summary: The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) resource provides tools for query, analysis and visualization of the 3D structures in the PDB archive. As the mobile Web is starting to surpass desktop and laptop usage, scientists and educators are beginning to integrate mobile devices into their research and teaching. In response, we have developed the RCSB PDB Mobile app for the iOS and Android mobile platforms to enable fast and convenient access to RCSB PDB data and services. Using the app, users from the general public to expert researchers can quickly search and visualize biomolecules, and add personal annotations via the RCSB PDB’s integrated MyPDB service. Availability and implementation: RCSB PDB Mobile is freely available from the Apple App Store and Google Play (http://www.rcsb.org). Contact: pwrose@ucsd.edu PMID:25183487

  16. Biochemical studies in Normal Pressure Hydrocephalus (NPH) patients: change in CSF levels of amyloid precursor protein (APP), amyloid-beta (Aβ) peptide and phospho-tau.

    PubMed

    Ray, Balmiki; Reyes, Patricio F; Lahiri, Debomoy K

    2011-04-01

    Normal Pressure Hydrocephalus (NPH) is one of the causes of dementia of the elderly characterized by impaired mental function, gait difficulties and urinary incontinence. Previously, it was proposed that some of the NPH patients may develop Alzheimer's disease (AD) like pathology. Aim of this study was to compare levels of different CSF biomarkers, including total secreted β-amyloid precursor protein (sAPP), sAPP-alpha form (sAPPα), amyloid-beta (Aβ) peptide, total-tau protein and hyperphosphorylated-tau protein in subjects from NPH and Non-NPH Control (NNC). CSF was collected from 23 NPH patients and 13 Non-NPH controls by lumber puncture. Western blot analysis was performed to measure levels of sAPP-total. ELISA was used separately to determine levels of sAPPα, Aβ peptide, total-tau and phospho-tau proteins. We found a significant decrease in levels of total secreted APP, sAPPα and Aβ (1-42) in the CSF sample of NPH patients vs. NNC. We did not observe any change in levels of total-tau or phospho-tau in NPH vs. NNC subjects. Notably, phospho-tau level was significantly increased in the NPH patients, who were suffering from the disease for more than one year, vs. NNC. Among five biomarkers studied, decreased sAPP, sAPPα and Aβ (1-42) levels in CSF can be molecular markers to distinguish NPH cases from NNC. Disease severity can also be assessed by increased levels of CSF phospho-tau protein and the ratio of phospho-tau to Aβ (1-42), which might be a useful tool for predicting conversion of NPH individuals to other neurodegenerative disorders including Alzheimer's disease (AD).

  17. Bacterial and cell-free production of APP671-726 containing amyloid precursor protein transmembrane and metal-binding domains.

    PubMed

    Bocharova, O V; Urban, A S; Nadezhdin, K D; Bocharov, E V; Arseniev, A S

    2013-11-01

    More than half of the mutations associated with familiar Alzheimer's disease have been found in the transmembrane domain of amyloid precursor protein (APP). These pathogenic mutations presumably influence the APP transmembrane domain structural and dynamic properties and result in its conformational change or/and lateral dimerization. Despite much data about the pathogenesis of Alzheimer's disease, the initial steps of the pathogenesis remain unclear so far. For the investigation of the molecular basis of Alzheimer's disease, we selected amyloid precursor protein fragment APP671-726 containing the transmembrane and metal-binding domains. This fragment is the substrate of the γ-secretase complex whose abnormal activity leads to the formation of amyloidogenic Aβ42 peptides. This work for the first time describes a highly effective cell-free APP671-726 production method and improved method of bacterial synthesis. Both methods yield milligram quantities of isotope-labeled protein for structural study by high resolution NMR spectroscopy in membrane mimicking milieus.

  18. Safety, Acceptability, and Use of a Smartphone App, BlueIce, for Young People Who Self-Harm: Protocol for an Open Phase I Trial

    PubMed Central

    2016-01-01

    Background Up to 18% of adolescents will engage in an act of self-harm before young adulthood, with the majority of acts occurring in private. Mobile apps may offer a way of providing support for young people at times of distress to prevent self-harm. Objective This is a proof-of-concept study designed to explore the safety, acceptability, feasibility, and usability of a smartphone app, BlueIce, with young people who are self-harming. Methods In this phase I open trial we will evaluate BlueIce, a smartphone app developed and coproduced with young people with lived experience of self-harm. BlueIce includes a mood-monitoring diary, selection of mood-lifting techniques based on cognitive behavior therapy and dialectical behavior therapy, and direct access to emergency telephone numbers. We will recruit young people (n=50) attending specialist child and adolescent mental health services with a current or past history of self-harm to trial BlueIce as an adjunct to their usual care. Questionnaires and interviews will be completed at baseline, postfamiliarization (2 weeks), and at follow-up (12 weeks after baseline) to assess safety, app use, and acceptability. Interviews will be undertaken with clinicians to assess the feasibility of BlueIce within a clinical setting. Results Recruitment occurred between May and November 2016. The recruitment target was 50, and by the beginning of November 54 young people had been referred. Conclusions This study is the first to evaluate an app specifically developed with young people for young people (under the age of 18 years) who self-harm. It will determine whether BlueIce is acceptable, how often it is used, and whether it is safe and does not have any unintentional adverse effects. This information will determine whether a feasibility trial to test recruitment, randomization, retention, and appropriate outcome measures should be pursued. PMID:27852560

  19. The onset of the progression of acute phase response mechanisms induced by extreme impacts can be followed by the decrease in blood levels of positive acute phase proteins.

    NASA Astrophysics Data System (ADS)

    Larina, Olga; Bekker, Anna

    Studies performed at space flights and earth-based simulation models detected the plasma indices of acute phase reaction (APR), i.e. the increase of APR cytokine mediators and alterations in the production of blood acute phase proteins (APP) at the initial stages of adaptation to altered gravity conditions. Acute phase response is the principal constituent of the functional activity of innate immunity system. Changes in plasma APPs contents are considered to serve the restoration of homeostasis state. According to trends of their concentration shifts at the evolving of acute phase reaction APPs are denoted as positive, neutral, or negative. Plasma concentrations of positive acute phase proteins α1-acid glycoprotein (α1-AGP), α1-antitrypsin (α1-AT), and neutral α2-macroglobulin (α2-M) were measured in human study at 12-hour antiorthostatic position (AOP) with 15° head down tilt and hypoxia experiments at 14% oxygen in pressure chamber. Both of these impacts were shown to produce alterations in the APP levels indicative for acute phase response. Nevertheless, in AOP experiment noticeable decrease in α1-AGP concentration occurred by hour 12, and even more pronounced decline of α1-AGP and α1-AT were found on hypoxia hours 12 and 36. Acute phase proteins α1-AGP and α2-M possess the features of proteinase inhibitors. This function is implemented by the formation of complexes with the molecules of proteolytic enzymes which subsequently are removed from the blood flow. Transient decrease in plasma concentrations of protease inhibitors on early phases of APR development was reported to result from the growth of plasma protease activity due to cathepsin release from activated leukocytes, which had not yet been compensated by enhanced APP synthesis. Being a carrier protein for positively charged and neutral substances, α1-AGP shows pronounced elevation in its blood content during APR development. As assumed, it is required for the transportation of the increased

  20. Increases in the serum acute phase proteins after ozone exposure are associated with induction of genes in the lung but not liver

    EPA Science Inventory

    Acute Phase Response (APR), a systemic reaction to infection, trauma, and inflammation, is characterized by increases and decreases in plasma levels of positive and negative acute phase proteins (APP), respectively. Although the liver has been shown to contribute to APR in variou...

  1. Potential of acute phase proteins as predictor of postpartum uterine infections during transition period and its regulatory mechanism in dairy cattle

    PubMed Central

    Manimaran, A.; Kumaresan, A.; Jeyakumar, S.; Mohanty, T. K.; Sejian, V.; Kumar, Narender; Sreela, L.; Prakash, M. Arul; Mooventhan, P.; Anantharaj, A.; Das, D. N.

    2016-01-01

    Among the various systemic reactions against infection or injury, the acute phase response is the cascade of reaction and mostly coordinated by cytokines-mediated acute phase proteins (APPs) production. Since APPs are sensitive innate immune molecules, they are useful for early detection of inflammation in bovines and believed to be better discriminators than routine hematological parameters. Therefore, the possibility of using APPs as a diagnostic and prognostic marker of inflammation in major bovine health disorders including postpartum uterine infection has been explored by many workers. In this review, we discussed specifically importance of postpartum uterine infection, the role of energy balance in uterine infections and potential of APPs as a predictor of postpartum uterine infections during the transition period and its regulatory mechanism in dairy cattle. PMID:27051191

  2. Pan-neuronal expression of APL-1, an APP-related protein, disrupts olfactory, gustatory, and touch plasticity in Caenorhabditis elegans.

    PubMed

    Ewald, Collin Y; Cheng, Ruby; Tolen, Lana; Shah, Vishal; Gillani, Aneela; Nasrin, Afsana; Li, Chris

    2012-07-25

    Patients with Alzheimer's disease show age-related cognitive decline. Postmortem autopsy of their brains shows the presence of large numbers of senile plaques, whose major component is the β-amyloid peptide. The β-amyloid peptide is a cleavage product of the amyloid precursor protein (APP). In addition to the neurodegeneration associated with β-amyloid aggregation in Alzheimer's disease patients, mutations in APP in mammalian model organisms have also been shown to disrupt several behaviors independent of visible amyloid plaque formation. However, the pathways in which APP function are unknown and difficult to unravel in mammals. Here we show that pan-neuronal expression of APL-1, the Caenorhabditis elegans ortholog of APP, disrupts several behaviors, such as olfactory and gustatory learning behavior and touch habituation. These behaviors are mediated by distinct neural circuits, suggesting a broad impact of APL-1 on sensory plasticity in C. elegans. Furthermore, we found that disruption of these three behaviors requires activity of the TGFβ pathway and reduced activity of the insulin pathway. These results suggest pathways and molecular components that may underlie behavioral plasticity in mammals and in patients with Alzheimer's disease.

  3. Pan-Neuronal Expression of APL-1, an APP-Related Protein, Disrupts Olfactory, Gustatory, and Touch Plasticity in Caenorhabditis elegans

    PubMed Central

    Ewald, Collin Y.; Cheng, Ruby; Tolen, Lana; Shah, Vishal; Gillani, Aneela; Nasrin, Afsana

    2012-01-01

    Patients with Alzheimer's disease show age-related cognitive decline. Postmortem autopsy of their brains shows the presence of large numbers of senile plaques, whose major component is the β-amyloid peptide. The β-amyloid peptide is a cleavage product of the amyloid precursor protein (APP). In addition to the neurodegeneration associated with β-amyloid aggregation in Alzheimer's disease patients, mutations in APP in mammalian model organisms have also been shown to disrupt several behaviors independent of visible amyloid plaque formation. However, the pathways in which APP function are unknown and difficult to unravel in mammals. Here we show that pan-neuronal expression of APL-1, the Caenorhabditis elegans ortholog of APP, disrupts several behaviors, such as olfactory and gustatory learning behavior and touch habituation. These behaviors are mediated by distinct neural circuits, suggesting a broad impact of APL-1 on sensory plasticity in C. elegans. Furthermore, we found that disruption of these three behaviors requires activity of the TGFβ pathway and reduced activity of the insulin pathway. These results suggest pathways and molecular components that may underlie behavioral plasticity in mammals and in patients with Alzheimer's disease. PMID:22836251

  4. Focally Elevated Creatine Detected in Amyloid Precursor Protein (APP) Transgenic Mice and Alzheimer Disease Brain Tissue

    SciTech Connect

    Gallant,M.; Rak, M.; Szeghalmi, A.; Del Bigio, M.; Westaway, D.; Yang, J.; Julian, R.; Gough, K.

    2006-01-01

    The creatine/phosphocreatine system, regulated by creatine kinase, plays an important role in maintaining energy balance in the brain. Energy metabolism and the function of creatine kinase are known to be affected in Alzheimer diseased brain and in cells exposed to the {beta}-amyloid peptide. We used infrared microspectroscopy to examine hippocampal, cortical, and caudal tissue from 21-89-week-old transgenic mice expressing doubly mutant (K670N/M671L and V717F) amyloid precursor protein and displaying robust pathology from an early age. Microcrystalline deposits of creatine, suggestive of perturbed energetic status, were detected by infrared microspectroscopy in all animals with advanced plaque pathology. Relatively large creatine deposits were also found in hippocampal sections from post-mortem Alzheimer diseased human brain, compared with hippocampus from non-demented brain. We therefore speculate that this molecule is a marker of the disease process.

  5. RCSB PDB Mobile: iOS and Android mobile apps to provide data access and visualization to the RCSB Protein Data Bank

    SciTech Connect

    Quinn, Gregory B.; Bi, Chunxiao; Christie, Cole H.; Pang, Kyle; Prlic, Andreas; Nakane, Takanori; Zardecki, Christine; Voigt, Maria; Berman, Helen M.; Bourne, Philip E.; Rose, Peter W.

    2014-09-02

    The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) resource provides tools for query, analysis and visualization of the 3D structures in the PDB archive. As the mobile Web is starting to surpass desktop and laptop usage, scientists and educators are beginning to integrate mobile devices into their research and teaching. In response, we have developed the RCSB PDB Mobile app for the iOS and Android mobile platforms to enable fast and convenient access to RCSB PDB data and services. Lastly, using the app, users from the general public to expert researchers can quickly search and visualize biomolecules, and add personal annotations via the RCSB PDB's integrated MyPDB service.

  6. RCSB PDB Mobile: iOS and Android mobile apps to provide data access and visualization to the RCSB Protein Data Bank

    DOE PAGES

    Quinn, Gregory B.; Bi, Chunxiao; Christie, Cole H.; ...

    2014-09-02

    The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) resource provides tools for query, analysis and visualization of the 3D structures in the PDB archive. As the mobile Web is starting to surpass desktop and laptop usage, scientists and educators are beginning to integrate mobile devices into their research and teaching. In response, we have developed the RCSB PDB Mobile app for the iOS and Android mobile platforms to enable fast and convenient access to RCSB PDB data and services. Lastly, using the app, users from the general public to expert researchers can quickly search and visualize biomolecules,more » and add personal annotations via the RCSB PDB's integrated MyPDB service.« less

  7. Formation of Protein Condensed Phases: Nucleation Mechanisms.

    PubMed

    Vekilov, Peter G

    2012-04-04

    Proteins in solution form a number of condensed phases. Even omitting the amyloid structures formed after partial protein unfolding, these phases include crystals, polymers, and other solid aggregates, as well as dense liquids and gels. Some of these condensed phases underlie pathological conditions, others play a crucial role in the biological function of the respective protein or are an essential part of its laboratory or industrial processing. In this review, we summarize the fundamentals and recent findings on the kinetics of nucleation of dense liquid droplets and crystals. We define the transition from nucleation to spinodal decomposition for these two phase transitions. We review the two-step mechanism of protein crystal nucleation, in which mesoscopic metastable protein clusters serve as precursors to the ordered crystal nuclei. The concepts and mechanisms reviewed here provide powerful tools for control of the nucleation process by varying the solution thermodynamic parameters.

  8. A rapid solid-phase protein microsequencer.

    PubMed Central

    Walker, J E; Fearnley, I M; Blows, R A

    1986-01-01

    A solid-phase protein microsequencer is described that has been designed to determine protein sequences with subnanomolar quantities of protein. Its utility has been demonstrated by the determination of many sequences in subunits of mitochondrial F1-ATPase, in a protein isolated from mouse gap junctions and in the mitochondrial phosphate-transporter protein. It has a number of advantages over liquid- and gas-phase sequencers. Firstly, the degradation cycle takes 24 min, more than twice as fast as any other sequencer. This helps to reduce exposure of proteins to inimical reagents and increases throughput of samples. Secondly, polar amino acids such as phosphoserine, and polar derivatives formed by active-site photoaffinity labelling with 8-azido-ATP, are recovered quantitatively from the reaction column and can be positively identified. In other types of sequencer these polar derivatives, being somewhat insoluble in butyl chloride, tend to remain in the reaction chamber of the instrument and so are more difficult to identify. The solid-phase protein sequencer is also more suited than the liquid-phase instrument for analysis of proteolipids from membranes. These hydrophobic proteins tend to dissolve in organic solvents during washing steps in the liquid-phase instrument and are lost. Covalent attachment as used in the solid-phase instrument solves this problem. PMID:3800890

  9. APP Causes Hyperexcitability in Fragile X Mice.

    PubMed

    Westmark, Cara J; Chuang, Shih-Chieh; Hays, Seth A; Filon, Mikolaj J; Ray, Brian C; Westmark, Pamela R; Gibson, Jay R; Huber, Kimberly M; Wong, Robert K S

    2016-01-01

    Amyloid-beta protein precursor (APP) and metabolite levels are altered in fragile X syndrome (FXS) patients and in the mouse model of the disorder, Fmr1(KO) mice. Normalization of APP levels in Fmr1(KO) mice (Fmr1(KO) /APP(HET) mice) rescues many disease phenotypes. Thus, APP is a potential biomarker as well as therapeutic target for FXS. Hyperexcitability is a key phenotype of FXS. Herein, we determine the effects of APP levels on hyperexcitability in Fmr1(KO) brain slices. Fmr1(KO) /APP(HET) slices exhibit complete rescue of UP states in a neocortical hyperexcitability model and reduced duration of ictal discharges in a CA3 hippocampal model. These data demonstrate that APP plays a pivotal role in maintaining an appropriate balance of excitation and inhibition (E/I) in neural circuits. A model is proposed whereby APP acts as a rheostat in a molecular circuit that modulates hyperexcitability through mGluR5 and FMRP. Both over- and under-expression of APP in the context of the Fmr1(KO) increases seizure propensity suggesting that an APP rheostat maintains appropriate E/I levels but is overloaded by mGluR5-mediated excitation in the absence of FMRP. These findings are discussed in relation to novel treatment approaches to restore APP homeostasis in FXS.

  10. Ab-initio phasing in protein crystallography

    NASA Astrophysics Data System (ADS)

    van der Plas, J. L.; Millane, Rick P.

    2000-11-01

    The central problem in the determination of protein structures form x-ray diffraction dada (x-ray crystallography) corresponds to a phase retrieval problem with undersampled amplitude data. Algorithms for this problem that have an increased radius of convergence have the potential for reducing the amount of experimental work, and cost, involved in determining protein structures. We describe such an algorithm. Application of the algorithm to a simulated crystallographic problem shows that it converges to the correct solution, with no initial phase information, where currently used algorithms fail. The results lend support to the possibility of ab initio phasing in protein crystallography.

  11. Acute Phase Proteins in Cerebrospinal Fluid from Dogs with Naturally-Occurring Spinal Cord Injury

    PubMed Central

    Anderson, Kimberly M.; Welsh, C. Jane; Young, Colin; Levine, Gwendolyn J.; Kerwin, Sharon C.; Boudreau, C. Elizabeth; Reyes, Ismael; Mondragon, Armando; Griffin, John F.; Cohen, Noah D.

    2015-01-01

    Abstract Spinal cord injury (SCI) affects thousands of people each year and there are no treatments that dramatically improve clinical outcome. Canine intervertebral disc herniation is a naturally-occurring SCI that has similarities to human injury and can be used as a translational model for evaluating therapeutic interventions. Here, we characterized cerebrospinal fluid (CSF) acute phase proteins (APPs) that have altered expression across a spectrum of neurological disorders, using this canine model system. The concentrations of C-reactive protein (CRP), haptoglobin (Hp), alpha-1-glycoprotein, and serum amyloid A were determined in the CSF of 42 acutely injured dogs, compared with 21 healthy control dogs. Concentrations of APPs also were examined with respect to initial injury severity and motor outcome 42 d post-injury. Hp concentration was significantly higher (p<0.0001) in the CSF of affected dogs, compared with healthy control dogs. Additionally, the concentrations of CRP and Hp were significantly (p=0.0001 and p=0.0079, respectively) and positively associated with CSF total protein concentration. The concentrations of CRP and Hp were significantly higher (p=0.0071 and p=0.0197, respectively) in dogs with severe injury, compared with those with mild-to-moderate SCI, but there was no significant correlation between assessed CSF APP concentrations and 42 d motor outcome. This study demonstrated that CSF APPs were dysregulated in dogs with naturally-occurring SCI and could be used as markers for SCI severity. As Hp was increased following severe SCI and is neuroprotective across a number of model systems, it may represent a viable therapeutic target. PMID:26186466

  12. Coexistence of Phases in a Protein Heterodimer

    PubMed Central

    Krokhotin, Andrey; Liwo, Adam; Niemi, Antti J.; Scheraga, Harold A.

    2012-01-01

    A heterodimer consisting of two or more different kinds of proteins can display an enormous number of distinct molecular architectures. The conformational entropy is an essential ingredient in the Helmholtz free energy and, consequently, these heterodimers can have a very complex phase structure. Here, it is proposed that there is a state of proteins, in which the different components of a heterodimer exist in different phases. For this purpose, the structures in the protein data bank (PDB) have been analyzed, with radius of gyration as the order parameter. Two major classes of heterodimers with their protein components coexisting in different phases have been identified. An example is the PDB structure 3DXC. This is a transcriptionally active dimer. One of the components is an isoform of the intra-cellular domain of the Alzheimer-disease related amyloid precursor protein (AICD), and the other is a nuclear multidomain adaptor protein in the Fe65 family. It is concluded from the radius of gyration that neither of the two components in this dimer is in its own collapsed phase, corresponding to a biologically active protein. The UNRES energy function has been utilized to confirm that, if the two components are separated from each other, each of them collapses. The results presented in this work show that heterodimers whose protein components coexist in different phases, can have intriguing physical properties with potentially important biological consequences. PMID:22830730

  13. Apps Developed by Academics

    ERIC Educational Resources Information Center

    Shing, Sophia; Yuan, Benjamin

    2016-01-01

    In the days of the digital Wild West, developers from all backgrounds have joined in the gold rush trying to profit from the almost unbridled spending of well-to-do parents on educational products. In 2016, the Apple App Store had over 80,000 educational apps. The proliferation of educational apps has happened at a furious pace and more apps are…

  14. Involvement of activated leukocytes in the regulation of plasma levels of acute phase proteins in microgravity simulation experiments

    NASA Astrophysics Data System (ADS)

    Larina, Olga; Bekker, Anna; Turin-Kuzmin, Alexey

    2016-07-01

    Earth-based studies of microgravity effects showed the induction of the mechanisms of acute phase reaction (APR). APR comprises the transition of stress-sensitive protein kinases of macrophages and other responsive cells into the active state and the phosphorylation of transcription factors which in turn stimulate the production of acute-phase reaction cytokines. Leukocyte activation is accompanied by the acceleration of the formation of oxygen radicals which can serve a functional indice of leukocyte cell state. The series of events at acute phase response result in selective changes in the synthesis of a number of secretory blood proteins (acute phase proteins, APPs) in liver cells thus contributing the recovery of homeostasis state in the organism. Earlier experiment with head-down tilt showed the increase in plasma concentrations of two cytokine mediators of acute phase response, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) being the outcome of the activation of producer cells, foremost, leukocytes. In experiment with 4-day dry immersion chemiluminescent (ChL) reply of the whole blood samples to a test stimulus were studied along with the measurements of plasma levels of APPs, namely, alpha1-antitrypsin (alpha1-AT), alpha1-acid glycoprotein (alpha1-AGP), alpha2-macroglobulin (alpha2-M), ceruloplasmin (Cer), haptoglobin (Hp), C3-complement component (C3), C-reactive protein (CRP). Eight individuals aged 21.2 ± 3.2 years were the test subjects in the investigation. Protein studies showed a noticeable increase in the mean plasma levels of all APPs measured in experiment thus producing the evidence of the activation of acute phase response mechanisms while individual patterns revealed variability during the immersion period. The overall trends were similar to these in the previous immersion series. The augment in the strength of signal in stimulated light emission tests was higher after 1- and 2-day of immersion exposure than before the

  15. Detection of β-amyloid peptide (1-16) and amyloid precursor protein (APP770) using spectroscopic ellipsometry and QCM techniques: a step forward towards Alzheimers disease diagnostics.

    PubMed

    Mustafa, M K; Nabok, A; Parkinson, D; Tothill, I E; Salam, F; Tsargorodskaya, A

    2010-12-15

    A highly sensitive method of spectroscopic ellipsometry in total internal reflection mode (TIRE) was exploited for detecting β-amyloid peptide (Aβ(1-16)) in the direct immune reaction with monoclonal DE2 antibodies (raised against Aβ(1-16)) electrostatically immobilised on the surface of gold. A rapid detection of Aβ(1-16) in a wide range of concentrations from 5 μg/ml down to 0.05 ng/ml was achieved using a cost-effective and label-free direct immunoassay format. TIRE dynamic spectral measurements proved that the immune reaction between DE2 monoclonal antibodies and Aβ(1-16) is highly specific with the affinity constant K(D)=1.46×10(-8) mol/l. The same DE2 antibodies were utilised for detection of amyloid precursor protein APP(770), a larger protein containing Aβ(1-16) domain, using the quartz crystal microbalance (QCM) measurements in liquid. A combination of QCM and TIRE kinetics results allowed the evaluation of the originally unknown concentration of APP(770) in complete medium solution containing other proteins, salts, and amino acids.

  16. Determination of ceruloplasmin, some other acute phase proteins, and biochemical parameters in cows with endometritis

    PubMed Central

    Kaya, S.; Merhan, O.; Kacar, C.; Colak, A.; Bozukluhan, K.

    2016-01-01

    Aim: The aim of this study is to determine serum ceruloplasmin levels in cows with endometritis of varying degrees of severity and to establish whether or not there is a correlation between acute phase protein (APP) levels and biochemical parameters. Material and Methods: The study was conducted with 100 Brown Swiss cows (3-8 years of age) on days 28-32 postpartum. Cows were divided into endometritis (mild, moderate, and severe endometriosis) and healthy groups based on ultrasonography, vaginoscopy, and cytological examination. Blood samples were collected from all cows. Levels of haptoglobin (Hp), serum amyloid A (SAA), ceruloplasmin, albumin, and some biochemical parameters were analyzed. Results: Hp, SAA, and ceruloplasmin levels were higher in cows with endometritis than in healthy cows (p=0.001), and the levels of these APPs increased as endometritis became more severe (p=0.001). Some significant correlations were found between APPs and the biochemical parameters that were analyzed. In conclusion, it was determined that ceruloplasmin levels increase significantly in the presence of endometritis and proportionate to the severity of endometritis. A significant correlation was found between ceruloplasmin levels and Hp and SAA levels. Conclusion: It was concluded that ceruloplasmin levels can be used in the diagnosis of endometritis as an alternative to Hp and SAA levels. PMID:27847413

  17. APP physiological and pathophysiological functions: insights from animal models.

    PubMed

    Guo, Qinxi; Wang, Zilai; Li, Hongmei; Wiese, Mary; Zheng, Hui

    2012-01-01

    The amyloid precursor protein (APP) has been under intensive study in recent years, mainly due to its critical role in the pathogenesis of Alzheimer's disease (AD). β-Amyloid (Aβ) peptides generated from APP proteolytic cleavage can aggregate, leading to plaque formation in human AD brains. Point mutations of APP affecting Aβ production are found to be causal for hereditary early onset familial AD. It is very likely that elucidating the physiological properties of APP will greatly facilitate the understanding of its role in AD pathogenesis. A number of APP loss- and gain-of-function models have been established in model organisms including Caenorhabditis elegans, Drosophila, zebrafish and mouse. These in vivo models provide us valuable insights into APP physiological functions. In addition, several knock-in mouse models expressing mutant APP at a physiological level are available to allow us to study AD pathogenesis without APP overexpression. This article will review the current physiological and pathophysiological animal models of APP.

  18. Smartphone apps for urolithiasis.

    PubMed

    Stevens, D J; McKenzie, K; Cui, H W; Noble, J G; Turney, B W

    2015-02-01

    There are an increasing number of healthcare smartphone applications ('apps') available. Urolithiasis presents a major healthcare burden. Patients are increasingly keen to educate themselves regarding the diagnosis and management of their condition. There is no formal regulation of healthcare apps, including a large number of apps relating to urolithiasis. This review aims to examine the range of apps available, and the prevalence of healthcare professional input. Four international smartphone app stores were searched: Apple's App Store, Google Play (Android), BlackBerry App World and the Windows Phone App store. A total of 42 unique apps were downloaded and analysed. Recorded data included the cost (£/$), publisher information, number of ratings, average rating and any documentation of medical professional involvement. Twenty-one (50%) apps required payment for download. The mean cost was £3.58 ($6.04) with range £0.61-£34.90 ($1.03-$58.87). Thirty-three (79%) of the 42 apps were designed to be used by patients. Fifteen (36%) of the 42 apps had clear input from health professionals. Twenty-two apps offered patient information, including dietary advice on lowering calcium intake, which is contrary to current evidence-based practice. We conclude that urolithiasis apps have future potential to inform both patients and healthcare professionals on stone management. However, inaccuracies in the recommendations made by some apps can be misleading or even harmful due to a lack of specialist involvement. We recommend improving the usefulness of these apps by seeking a 'quality stamp' from recognised urological organisations and greater clinician involvement in future app development.

  19. APP Causes Hyperexcitability in Fragile X Mice

    PubMed Central

    Westmark, Cara J.; Chuang, Shih-Chieh; Hays, Seth A.; Filon, Mikolaj J.; Ray, Brian C.; Westmark, Pamela R.; Gibson, Jay R.; Huber, Kimberly M.; Wong, Robert K. S.

    2016-01-01

    Amyloid-beta protein precursor (APP) and metabolite levels are altered in fragile X syndrome (FXS) patients and in the mouse model of the disorder, Fmr1KO mice. Normalization of APP levels in Fmr1KO mice (Fmr1KO/APPHET mice) rescues many disease phenotypes. Thus, APP is a potential biomarker as well as therapeutic target for FXS. Hyperexcitability is a key phenotype of FXS. Herein, we determine the effects of APP levels on hyperexcitability in Fmr1KO brain slices. Fmr1KO/APPHET slices exhibit complete rescue of UP states in a neocortical hyperexcitability model and reduced duration of ictal discharges in a CA3 hippocampal model. These data demonstrate that APP plays a pivotal role in maintaining an appropriate balance of excitation and inhibition (E/I) in neural circuits. A model is proposed whereby APP acts as a rheostat in a molecular circuit that modulates hyperexcitability through mGluR5 and FMRP. Both over- and under-expression of APP in the context of the Fmr1KO increases seizure propensity suggesting that an APP rheostat maintains appropriate E/I levels but is overloaded by mGluR5-mediated excitation in the absence of FMRP. These findings are discussed in relation to novel treatment approaches to restore APP homeostasis in FXS. PMID:28018172

  20. Acute phase protein concentrations after limited distance and long distance endurance rides in horses.

    PubMed

    Cywińska, Anna; Szarska, Ewa; Górecka, Renata; Witkowski, Lucjan; Hecold, Mateusz; Bereznowski, Andrzej; Schollenberger, Antoni; Winnicka, Anna

    2012-12-01

    Acute phase proteins (APP) have been described as useful for assessing health in human and animal patients, as they closely reflect the acute phase reaction (APR). In humans and dogs a reaction analogous to APR has also been described after prolonged or strenuous exercise. The aim of this study was to determine, if similar reactions occur in endurance horses after limited and long distance rides. Seventeen horses that successfully completed various distance competitions were tested. Routine haematological and biochemical tests were performed and the concentrations of serum amyloid A (SAA), C-reactive protein (CRP) and haptoglobin were measured. Typical endurance exercise-induced haematological and biochemical changes were observed in all horses, regardless the distance. After long distance rides, the level of SAA markedly increased, but CRP and haptoglobin concentrations remained unchanged. After limited distance rides no changes in the levels of APPs were noted. Exercise-induced APR in horses occurred only after prolonged, strenuous exertion, and differed from APR in inflammation in that only SAA concentration was increased.

  1. Acute phase proteins increase with sarcoptic mange status and severity in Iberian ibex (Capra pyrenaica, Schinz 1838).

    PubMed

    Ráez-Bravo, Arián; Granados, José Enrique; Cerón, José Joaquín; Cano-Manuel, Francisco Javier; Fandos, Paulino; Pérez, Jesús María; Espinosa, José; Soriguer, Ramón Casimiro; López-Olvera, Jorge Ramón

    2015-11-01

    Sarcoptic mange is a contagious skin disease caused by Sarcoptes scabiei, affecting both domestic and wild mammals, including the Iberian ibex (Capra pyrenaica), a medium-sized mountain ungulate almost endemic to the Iberian Peninsula. Acute phase proteins (APPs) could be an indicator of sarcoptic mange disease and severity in Iberian ibex. Serum samples from 131 healthy and sarcoptic mange-affected Iberian ibexes were collected from 2005 to 2012 in Sierra Nevada Natural Space in southern Spain. Serum alpha-1-acid glycoprotein (AGP), serum amyloid A (SAA) and haptoglobin (Hp) concentrations were quantified, and statistically significant differences according to sarcoptic mange disease and severity were assessed. Both AGP and SAA were significantly higher in the sarcoptic mange-affected ibexes than in the healthy ones as well as in the severely affected ibexes as compared to those with less than 50 % of the body surface affected. For the first time, changes in APP are reported in relation to sarcoptic mange in Iberian ibex. It is also reported for the first time that the intensity of APP increase depends on the severity of sarcoptic mange, which could be related with the pathological secondary amyloidosis, leading to organ dysfunction in severely mange-affected animals. Species and population differences in the increase of APP in response to sarcoptic mange could indicate individual and population differences in the immune capability of each population to deal with mange, population prevalence and mortality being the last indicators of such sensitivity.

  2. Alcadein cleavages by amyloid beta-precursor protein (APP) alpha- and gamma-secretases generate small peptides, p3-Alcs, indicating Alzheimer disease-related gamma-secretase dysfunction.

    PubMed

    Hata, Saori; Fujishige, Sayaka; Araki, Yoichi; Kato, Naoko; Araseki, Masahiko; Nishimura, Masaki; Hartmann, Dieter; Saftig, Paul; Fahrenholz, Falk; Taniguchi, Miyako; Urakami, Katsuya; Akatsu, Hiroyasu; Martins, Ralph N; Yamamoto, Kazuo; Maeda, Masahiro; Yamamoto, Tohru; Nakaya, Tadashi; Gandy, Sam; Suzuki, Toshiharu

    2009-12-25

    Alcadeins (Alcs) constitute a family of neuronal type I membrane proteins, designated Alc(alpha), Alc(beta), and Alc(gamma). The Alcs express in neurons dominantly and largely colocalize with the Alzheimer amyloid precursor protein (APP) in the brain. Alcs and APP show an identical function as a cargo receptor of kinesin-1. Moreover, proteolytic processing of Alc proteins appears highly similar to that of APP. We found that APP alpha-secretases ADAM 10 and ADAM 17 primarily cleave Alc proteins and trigger the subsequent secondary intramembranous cleavage of Alc C-terminal fragments by a presenilin-dependent gamma-secretase complex, thereby generating "APP p3-like" and non-aggregative Alc peptides (p3-Alcs). We determined the complete amino acid sequence of p3-Alc(alpha), p3-Alc(beta), and p3-Alc(gamma), whose major species comprise 35, 37, and 31 amino acids, respectively, in human cerebrospinal fluid. We demonstrate here that variant p3-Alc C termini are modulated by FAD-linked presenilin 1 mutations increasing minor beta-amyloid species Abeta42, and these mutations alter the level of minor p3-Alc species. However, the magnitudes of C-terminal alteration of p3-Alc(alpha), p3-Alc(beta), and p3-Alc(gamma) were not equivalent, suggesting that one type of gamma-secretase dysfunction does not appear in the phenotype equivalently in the cleavage of type I membrane proteins. Because these C-terminal alterations are detectable in human cerebrospinal fluid, the use of a substrate panel, including Alcs and APP, may be effective to detect gamma-secretase dysfunction in the prepathogenic state of Alzheimer disease subjects.

  3. Age-dependent cognitive decline in the APP23 model precedes amyloid deposition.

    PubMed

    Van Dam, Debby; D'Hooge, Rudi; Staufenbiel, Matthias; Van Ginneken, Chris; Van Meir, Frans; De Deyn, Peter P

    2003-01-01

    Heterozygous APP23 mice, expressing human amyloid-precursor protein with the Swedish double mutation and control littermates, were subjected to behavioral and neuromotor tasks at the age of 6-8 weeks, 3 and 6 months. A hidden-platform Morris-type water maze showed an age-dependent decline of spatial memory capacities in the APP23 model. From the age of 3 months onwards, the APP23 mice displayed major learning and memory deficits as demonstrated by severely impaired learning curves during acquisition and impaired probe trial performance. In addition to the cognitive deficit, APP23 mice displayed disturbed activity patterns. Overnight cage-activity recording showed hyperactivity in the transgenics for the three age groups tested. However, a short 2-h recording during dusk phase demonstrated lower activity levels in 6-month-old APP23 mice as compared to controls. Moreover, at this age, APP23 mice differed from control littermates in exploration and activity levels in the open-field paradigm. These findings are reminiscent of disturbances in circadian rhythms and activity observed in Alzheimer patients. Determination of plaque-associated human amyloid-beta 1-42 peptides in brain revealed a fivefold increase in heterozygous APP23 mice at 6 months as compared to younger transgenics. This increase coincided with the first appearance of plaques in hippocampus and neocortex. Spatial memory deficits preceded plaque formation and increase in plaque-associated amyloid-beta 1-42 peptides, but probe trial performance did correlate negatively with soluble amyloid-beta brain concentration in 3-month-old APP23 mutants. Detectable plaque formation is not the (only) causal factor contributing to memory defects in the APP23 model.

  4. Surface Trafficking of APP and BACE in Live Cells.

    PubMed

    Bauereiss, Anna; Welzel, Oliver; Jung, Jasmin; Grosse-Holz, Simon; Lelental, Natalia; Lewczuk, Piotr; Wenzel, Eva M; Kornhuber, Johannes; Groemer, Teja W

    2015-06-01

    Amyloid-β (Aβ)-peptide, the major constituent of the plaques that develop during Alzheimer's disease, is generated via the cleavage of Aβ precursor protein (APP) by β-site APP-cleaving enzyme (BACE). Using live-cell imaging of APP and BACE labeled with pH-sensitive proteins, we could detect the release events of APP and BACE and their distinct kinetics. We provide kinetic evidence for the cleavage of APP by α-secretase on the cellular surface after exocytosis. Furthermore, simultaneous dual-color evanescent field illumination revealed that the two proteins are trafficked to the surface in separate compartments. Perturbing the membrane lipid composition resulted in a reduced frequency of exocytosis and affected BACE more strongly than APP. We propose that surface fusion frequency is a key factor regulating the aggregation of APP and BACE in the same membrane compartment and that this process can be modulated via pharmacological intervention.

  5. APP processing and the APP-KPI domain involvement in the amyloid cascade.

    PubMed

    Menéndez-González, M; Pérez-Pinera, P; Martínez-Rivera, M; Calatayud, M T; Blázquez Menes, B

    2005-01-01

    Alternative APP mRNA splicing can generate isoforms of APP containing a Kunitz protease inhibitor (KPI) domain. KPI is one of the main serine protease inhibitors. Protein and mRNA KPI(+)APP levels are elevated in Alzheimer's disease (AD) brain and are associated with increased amyloid beta deposition. In the last years increasing evidence on multiple points in the amyloid cascade where KPI(+)APP is involved has been accumulated, admitting an outstanding position in the pathogenesis of AD to the KPI domain. This review focuses on the APP processing, the molecular activity of KPI and its physiological and pathological roles and the KPI involvement in the amyloid cascade through the nerve growth factor, the lipoprotein receptor-related protein, the tumor necrosis factor-alpha converting enzyme and the Notch1 protein.

  6. Protein-targeted corona phase molecular recognition

    PubMed Central

    Bisker, Gili; Dong, Juyao; Park, Hoyoung D.; Iverson, Nicole M.; Ahn, Jiyoung; Nelson, Justin T.; Landry, Markita P.; Kruss, Sebastian; Strano, Michael S.

    2016-01-01

    Corona phase molecular recognition (CoPhMoRe) uses a heteropolymer adsorbed onto and templated by a nanoparticle surface to recognize a specific target analyte. This method has not yet been extended to macromolecular analytes, including proteins. Herein we develop a variant of a CoPhMoRe screening procedure of single-walled carbon nanotubes (SWCNT) and use it against a panel of human blood proteins, revealing a specific corona phase that recognizes fibrinogen with high selectivity. In response to fibrinogen binding, SWCNT fluorescence decreases by >80% at saturation. Sequential binding of the three fibrinogen nodules is suggested by selective fluorescence quenching by isolated sub-domains and validated by the quenching kinetics. The fibrinogen recognition also occurs in serum environment, at the clinically relevant fibrinogen concentrations in the human blood. These results open new avenues for synthetic, non-biological antibody analogues that recognize biological macromolecules, and hold great promise for medical and clinical applications. PMID:26742890

  7. Protein-targeted corona phase molecular recognition.

    PubMed

    Bisker, Gili; Dong, Juyao; Park, Hoyoung D; Iverson, Nicole M; Ahn, Jiyoung; Nelson, Justin T; Landry, Markita P; Kruss, Sebastian; Strano, Michael S

    2016-01-08

    Corona phase molecular recognition (CoPhMoRe) uses a heteropolymer adsorbed onto and templated by a nanoparticle surface to recognize a specific target analyte. This method has not yet been extended to macromolecular analytes, including proteins. Herein we develop a variant of a CoPhMoRe screening procedure of single-walled carbon nanotubes (SWCNT) and use it against a panel of human blood proteins, revealing a specific corona phase that recognizes fibrinogen with high selectivity. In response to fibrinogen binding, SWCNT fluorescence decreases by >80% at saturation. Sequential binding of the three fibrinogen nodules is suggested by selective fluorescence quenching by isolated sub-domains and validated by the quenching kinetics. The fibrinogen recognition also occurs in serum environment, at the clinically relevant fibrinogen concentrations in the human blood. These results open new avenues for synthetic, non-biological antibody analogues that recognize biological macromolecules, and hold great promise for medical and clinical applications.

  8. Protein-targeted corona phase molecular recognition

    NASA Astrophysics Data System (ADS)

    Bisker, Gili; Dong, Juyao; Park, Hoyoung D.; Iverson, Nicole M.; Ahn, Jiyoung; Nelson, Justin T.; Landry, Markita P.; Kruss, Sebastian; Strano, Michael S.

    2016-01-01

    Corona phase molecular recognition (CoPhMoRe) uses a heteropolymer adsorbed onto and templated by a nanoparticle surface to recognize a specific target analyte. This method has not yet been extended to macromolecular analytes, including proteins. Herein we develop a variant of a CoPhMoRe screening procedure of single-walled carbon nanotubes (SWCNT) and use it against a panel of human blood proteins, revealing a specific corona phase that recognizes fibrinogen with high selectivity. In response to fibrinogen binding, SWCNT fluorescence decreases by >80% at saturation. Sequential binding of the three fibrinogen nodules is suggested by selective fluorescence quenching by isolated sub-domains and validated by the quenching kinetics. The fibrinogen recognition also occurs in serum environment, at the clinically relevant fibrinogen concentrations in the human blood. These results open new avenues for synthetic, non-biological antibody analogues that recognize biological macromolecules, and hold great promise for medical and clinical applications.

  9. Similarities in acute phase protein response during hibernation in black bears and major depression in humans: A response to underlying metabolic depression?

    USGS Publications Warehouse

    Tsiouris, J.A.; Chauhan, V.P.S.; Sheikh, A.M.; Chauhan, A.; Malik, M.; Vaughan, M.R.

    2004-01-01

    This study investigated the effects of hibernation with mild hypothermia and the stress of captivity on levels of six acute-phase proteins (APPs) in serial samples of serum from 11 wild and 6 captive black bears (Ursus americanus Pallas, 1780) during active and hibernating states. We hypothesize that during hibernation with mild hypothermia, bears would show an APP response similar to that observed in major depression. Enzyme-linked immunoabsorbent assay was used to measure alpha2-macroglobulin and C-reactive protein, and a nephelometer to measure alpha1-antitrypsin, haptoglobin, ceruloplasmin, and transferrin. Levels of all other proteins except ceruloplasmin were significantly elevated during hibernation in both wild and captive bears at the p < 0.05 to p < 0.001 level. Alpha 2-macroglobulin and C-reactive-protein levels were increased in captive versus wild bears in both active and hibernating states at the p < 0.01 to p < 0.0001 level. During hibernation with mild hypothermia, black bears do not show immunosuppression, but show an increased APP response similar to that in patients with major depression. This APP response is explained as an adaptive response to the underlying metabolic depression in both conditions. Metabolic depression in hibernating bears is suggested as a natural model for research to explain the neurobiology of depression.

  10. C-reactive protein, haptoglobin and Pig-Major acute phase protein profiles of pigs infected experimentally by different isolates of porcine reproductive and respiratory syndrome virus.

    PubMed

    Saco, Y; Martínez-Lobo, F; Cortey, M; Pato, R; Peña, R; Segalés, J; Prieto, C; Bassols, A

    2016-02-01

    Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) is the etiologic agent of PRRS, one of the most important diseases in swine worldwide. In the present work, the effects of different PRRSV strains were tested on a piglet experimental model to study the induced acute phase response. For this purpose, pigs (n=15 for each group) were intranasally inoculated with one of five PRRSV strains (isolates EU10, 12, 17, 18 from genotype 1 and isolate JA-142 from genotype 2). The acute phase response was monitored by measuring acute phase proteins (APPs). Specifically, the serum concentration of haptoglobin (Hp), C-reactive protein (CRP) and Pig-Major Acute Protein (Pig-MAP) was determined at 0, 3, 6, 9, 12, 15, 18 and 21 days p.i. Clinical signs and growth performance were also monitored during the experiment. All animals became viremic after inoculation during the study period. The APP response was heterogeneous and dependent on the strain, being strains EU10, EU 18 and JA-142 those that induced the highest response and the strongest clinical signs. In general, Hp was the most sensitive biomarker for PRRSV infection, CRP behaved as moderate and Pig-MAP was the less responsive during the course of PRRSV experimental infection. Hp and CRP were significantly discriminatory between infected and control pigs, but not Pig-MAP.

  11. Gas-Phase Photoionization Of A Protein

    NASA Astrophysics Data System (ADS)

    Milosavljevic, A. R.; Giuliani, A.; Nicolas, C.; Gil, J.-F.; Lemaire, J.; Refregiers, M.; Nahon, L.

    2010-07-01

    We present preliminary results on gas phase photoionization of electrosprayproduced multiply protonated cytochrome c protein (104 amino acids; ˜12.4 kDa), which has been achieved with a newly developed experimental system for spectroscopy of electrosprayed ions in a linear quadrupole ion trap using a monochromatized vacuum ultraviolet (VUV) synchrotron radiation and tandem mass spectrometry method. The investigation of proteins in the gas phase, where they are free of the influence of counterions and solvent molecules, offer a possibility to understand their intrinsic molecular properties. However, due to limited both ion densities and available number of photons, the use of synchrotron radiation for the trapped ions spectroscopy is a rather challenging task. The feasibility of coupling a Fourier transform ion cyclotron resonance ion trap with soft x-ray synchrotron beamline and the first successful use of synchrotron radiation for spectroscopy of electrosprayed negative ions stored in a three-dimensional quadrupole ion trap have been demonstrated only recently (R. Thissen et al., 2008, Phys. Rev. Lett., 100, 223001; A. Giulliani et al., Proc. 57th ASMS Conf., Philadelphia, 2009). The present results are the first reported on photoionization of kDa species in the gas phase and are valuable regarding both a fundamental interest of accessing physical properties of large biological ions isolated in vacuo and potential development of a new technique for proteomics.

  12. The role and importance of glycosylation of acute phase proteins with focus on alpha-1 antitrypsin in acute and chronic inflammatory conditions.

    PubMed

    McCarthy, Cormac; Saldova, Radka; Wormald, Mark R; Rudd, Pauline M; McElvaney, Noel G; Reeves, Emer P

    2014-07-03

    Acute phase proteins (APPs) are a group of circulating plasma proteins which undergo changes quantitatively or qualitatively at the time of inflammation. Many of these APPs are glycosylated, and it has been shown that alterations in glycosylation may occur in inflammatory and malignant conditions. Changes in glycosylation have been studied as potential biomarkers in cancer and also in chronic inflammatory conditions and have been shown to correlate with disease severity in certain conditions. Serine protease inhibitors (serpins), many of which are also APPs, are proteins involved in the control of proteases in numerous pathways. Alpha-1 Antitrypsin (AAT) is the most abundant serpin within the circulation and is an APP which has been shown to increase in response to inflammation. The primary role of AAT is maintaining the protease/antiprotease balance in the lung, but it also possesses important anti-inflammatory and immune-modulating properties. Several glycoforms of AAT exist, and they possess differing properties in regard to plasma half-life and stability. Glycosylation may also be important in determining the immune modulatory properties of AAT. The review will focus on the role and importance of glycosylation in acute phase proteins with particular attention to AAT and its use as a biomarker of disease. The review describes the processes involved in glycosylation, how glycosylation changes in differing disease states, and the alterations that occur to glycans of APPs with disease and inflammation. Finally, the review explores the importance of changes in glycosylation of AAT at times of inflammation and in malignant conditions and how this may impact upon the functions of AAT.

  13. NGF controls APP cleavage by downregulating APP phosphorylation at Thr668: relevance for Alzheimer's disease.

    PubMed

    Triaca, Viviana; Sposato, Valentina; Bolasco, Giulia; Ciotti, Maria Teresa; Pelicci, Piergiuseppe; Bruni, Amalia C; Cupidi, Chiara; Maletta, Raffaele; Feligioni, Marco; Nisticò, Robert; Canu, Nadia; Calissano, Pietro

    2016-08-01

    NGF has been implicated in forebrain neuroprotection from amyloidogenesis and Alzheimer's disease (AD). However, the underlying molecular mechanisms are still poorly understood. Here, we investigated the role of NGF signalling in the metabolism of amyloid precursor protein (APP) in forebrain neurons using primary cultures of septal neurons and acute septo-hippocampal brain slices. In this study, we show that NGF controls the basal level of APP phosphorylation at Thr668 (T668) by downregulating the activity of the Ser/Thr kinase JNK(p54) through the Tyr kinase signalling adaptor SH2-containing sequence C (ShcC). We also found that the specific NGF receptor, Tyr kinase A (TrkA), which is known to bind to APP, fails to interact with the fraction of APP molecules phosphorylated at T668 (APP(pT668) ). Accordingly, the amount of TrkA bound to APP is significantly reduced in the hippocampus of ShcC KO mice and of patients with AD in which elevated APP(pT668) levels are detected. NGF promotes TrkA binding to APP and APP trafficking to the Golgi, where APP-BACE interaction is hindered, finally resulting in reduced generation of sAPPβ, CTFβ and amyloid-beta (1-42). These results demonstrate that NGF signalling directly controls basal APP phosphorylation, subcellular localization and BACE cleavage, and pave the way for novel approaches specifically targeting ShcC signalling and/or the APP-TrkA interaction in AD therapy.

  14. Proteasome-mediated degradation of the C-terminus of the Alzheimer's disease beta-amyloid protein precursor: effect of C-terminal truncation on production of beta-amyloid protein.

    PubMed

    Nunan, Janelle; Williamson, Nicholas A; Hill, Andrew F; Sernee, M Fleur; Masters, Colin L; Small, David H

    2003-11-01

    The beta-amyloid protein (Abeta) is derived by proteolytic processing of the amyloid protein precursor (APP). Cleavage of APP by beta-secretase generates a C-terminal fragment (APP-CTFbeta), which is subsequently cleaved by gamma-secretase to produce Abeta. Our previous studies have shown that the proteasome can cleave the C-terminal cytoplasmic domain of APP. To identify proteasome cleavage sites in APP, two peptides homologous to the C-terminus of APP were incubated with recombinant 20S proteasome. Cleavage of the peptides was monitored by reversed phase high-performance liquid chromatography and mass spectrometry. Proteasome cleaved the APP C-terminal peptides at several sites, including a region around the sequence YENPTY that interacts with several APP-binding proteins. To examine the effect of this cleavage on Abeta production, APP-CTFbeta and mutant forms of APP-CTFbeta terminating on either side of the YENPTY sequence were expressed in CHO cells. Truncation of APP-CTFbeta on the N-terminal side of the YENPTY sequence at residue 677 significantly decreased the amount of Abeta produced, whereas truncation on the C-terminal side of residue 690 had little effect. The results suggest that proteasomal cleavage of the cytosolic domain of APP at the YENPTY sequence decreases gamma-secretase processing, and consequently inhibits Abeta production. Therefore, the proteasome-dependent trafficking pathway of APP may be a valid therapeutic target for altering Abeta production in the Alzheimer's disease brain.

  15. Apps for Ancient Civilizations

    ERIC Educational Resources Information Center

    Thompson, Stephanie

    2011-01-01

    This project incorporates technology and a historical emphasis on science drawn from ancient civilizations to promote a greater understanding of conceptual science. In the Apps for Ancient Civilizations project, students investigate an ancient culture to discover how people might have used science and math smartphone apps to make their lives…

  16. Mobile Apps for Librarians

    ERIC Educational Resources Information Center

    Power, June L.

    2013-01-01

    In an increasing mobile environment, library and reading-related activities often take place on a phone or tablet device. Not only does this mean that library Web sites must keep mobile navigability in mind, but also develop and utilize apps that allow patrons to interact with information and with libraries. While apps do not serve every purpose,…

  17. Acute-phase proteins, oxidative stress biomarkers, proinflammatory cytokines, and cardiac troponin in Arabian mares affected with pyometra.

    PubMed

    El-Bahr, S M; El-Deeb, W M

    2016-09-01

    New biomarkers are essential for diagnosis of pyometra in mares. In this context, 12 subfertile Arabian mares suffered from pyometra were admitted to the Veterinary Teaching Hospital. The basis for diagnosis of pyometra was positive findings of clinical examination and rectal palpation. Blood samples were collected from diseased animals and from five Arabian healthy mares, which were considered as control group. Acute-phase proteins (APP), oxidative stress biomarkers, proinflammatory cytokines, and cardiac troponin I were estimated in the harvested sera of both groups. Clinical examination revealed purulent yellowish fluid discharged from vagina of affected animals and rectal palpation of the reproductive tract revealed uterine distention. The biochemical analysis of the serum revealed significant increase in cardiac troponin I, creatin kinase, alkaline phosphatase, malondialdehyde, tumor necrosis factor α, interleukins 6, prostaglandin F2α, haptoglobin, and serum amyloid A and significant decrease in reduced glutathione, superoxide dismutase (SOD), total antioxidant capacity, and nitric oxide (NO) of mares affected with pyometra compare to control. Cardiac troponin I was positively correlated with aspartate aminotransferase, creatin kinase, malondialdehyde, alkaline phosphatase, tumor necrosis factor α, interleukins 6, prostaglandin F2α, haptoglobin and serum amyloid A and negatively correlated with glutathione, superoxide dismutase, total antioxidant capacity and nitric oxide in serum of mares affected with pyometra. Moreover, there was high positive correlation between proinflammatory cytokines and APP in serum of mares affected with pyometra. The present study suggests cardiac troponin I together with APP, proinflammatory cytokines, and oxidative stress parameters as biomarkers for pyometra in Arabian mares.

  18. Acute phase protein response during subclinical infection of pigs with H1N1 swine influenza virus.

    PubMed

    Pomorska-Mól, Małgorzata; Markowska-Daniel, Iwona; Pejsak, Zygmunt

    2012-10-12

    In the present study acute phase proteins (APPs) responses in pigs after subclinical infection with H1N1 swine influenza virus (SwH1N1) were evaluated. Fourteen 5 weeks old, seronegative piglets, both sexes were used. Ten of them were infected intranasally with SwH1N1. C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA) and pig major acute phase protein (Pig-MAP) concentrations in serum were measured using commercial ELISAs. No significant clinical signs were observed in any of the infected pigs, however, all infected animals developed specific antibodies against SwH1N1 and viral shedding was observed from 2 to 5 dpi. Only concentrations of Hp and SAA were significantly induced after infection, with mean maximum levels from days 1 to 2 post infection (dpi). The concentrations of CRP and Pig-MAP remained generally unchanged, however in half of infected pigs the concentration of CRP tended to increase at 1 dpi (but without statistical significance). The results of our study confirmed that monitoring of APPs may be useful for detection of subclinically infected pigs. The use of SAA or Hp and Pig-MAP may be a valuable in combination [i.e. Hp (increased concentration) and Pig-MAP (unchanged concentration)] to detect subclinically SIV infected pigs, or to identify pigs actually producing a large amount of virus. Additional studies need to be done in order to confirm these findings.

  19. SLiMScape 3.x: a Cytoscape 3 app for discovery of Short Linear Motifs in protein interaction networks.

    PubMed

    Olorin, Emily; O'Brien, Kevin T; Palopoli, Nicolas; Pérez-Bercoff, Åsa; Shields, Denis C; Edwards, Richard J

    2015-01-01

    Short linear motifs (SLiMs) are small protein sequence patterns that mediate a large number of critical protein-protein interactions, involved in processes such as complex formation, signal transduction, localisation and stabilisation. SLiMs show rapid evolutionary dynamics and are frequently the targets of molecular mimicry by pathogens. Identifying enriched sequence patterns due to convergent evolution in non-homologous proteins has proven to be a successful strategy for computational SLiM prediction. Tools of the SLiMSuite package use this strategy, using a statistical model to identify SLiM enrichment based on the evolutionary relationships, amino acid composition and predicted disorder of the input proteins. The quality of input data is critical for successful SLiM prediction. Cytoscape provides a user-friendly, interactive environment to explore interaction networks and select proteins based on common features, such as shared interaction partners. SLiMScape embeds tools of the SLiMSuite package for de novo SLiM discovery (SLiMFinder and QSLiMFinder) and identifying occurrences/enrichment of known SLiMs (SLiMProb) within this interactive framework. SLiMScape makes it easier to (1) generate high quality hypothesis-driven datasets for these tools, and (2) visualise predicted SLiM occurrences within the context of the network. To generate new predictions, users can select nodes from a protein network or provide a set of Uniprot identifiers. SLiMProb also requires additional query motif input. Jobs are then run remotely on the SLiMSuite server ( http://rest.slimsuite.unsw.edu.au) for subsequent retrieval and visualisation. SLiMScape can also be used to retrieve and visualise results from jobs run directly on the server. SLiMScape and SLiMSuite are open source and freely available via GitHub under GNU licenses.

  20. Systemic acute phase proteins response in calves experimentally infected with Eimeria zuernii.

    PubMed

    Lassen, Brian; Bangoura, Berit; Lepik, Triin; Orro, Toomas

    2015-09-15

    Acute phase proteins (APPs) have been demonstrated to be useful in evaluating general health stress and diseases in cattle. Serum amyloid A (SAA) and haptoglobin (Hp) are APPs that are produced during inflammation, and likely play a role in host immunological defence against Eimeria infection and the associated intestinal tissue damage. We investigated the involvement of SAA and HP in an experimental study, including three groups of calves: a control group (group 0, n=11), and two groups infected with either 150,000 or 250,000 Eimeria zuernii oocysts (group 1 (n=11) and group 2 (n=12), respectively). The calves were monitored for 28 days and data was collected on oocyst excretion, faecal score, animal weight, and SAA and Hp serum concentrations. Generalized linear mixed models showed that the clinical symptoms, indicated by an increase in the number of oocysts in the faeces and severe diarrhoea, manifested at patency for group 1 and 2. Serum Hp and SAA levels also increased during this period. Hp appeared to be a more sensitive marker than SAA, and differences between groups 1 and 2 were observed only for Hp. Linear regression models showed a negative association between weight gain and Hp concentrations, calculated as the area under the curve (AUC) during the overall experimental period and the patency period. A similar result was seen for SAA only during the patency period. This result supports the assumption that reduced weight gain due to E. zuernii infection is an immunologically driven process that involves an increase in APPs. A random intercept regression model of oocyst shedding groups showed that calves shedding 1-500 oocysts had reduced concentrations of Hp, indicating that a different immunological reaction occurs during mild shedding of E. zuernii oocysts than during more intensive shedding. A similar model was used to examine associations between faecal scores and Hp concentrations for each group. Group 2 calves with haemorrhagic diarrhoea displayed

  1. APP as a Protective Factor in Acute Neuronal Insults

    PubMed Central

    Hefter, Dimitri; Draguhn, Andreas

    2017-01-01

    Despite its key role in the molecular pathology of Alzheimer’s disease (AD), the physiological function of amyloid precursor protein (APP) is unknown. Increasing evidence, however, points towards a neuroprotective role of this membrane protein in situations of metabolic stress. A key observation is the up-regulation of APP following acute (stroke, cardiac arrest) or chronic (cerebrovascular disease) hypoxic-ischemic conditions. While this mechanism may increase the risk or severity of AD, APP by itself or its soluble extracellular fragment APPsα can promote neuronal survival. Indeed, different animal models of acute hypoxia-ischemia, traumatic brain injury (TBI) and excitotoxicity have revealed protective effects of APP or APPsα. The underlying mechanisms involve APP-mediated regulation of calcium homeostasis via NMDA receptors (NMDAR), voltage-gated calcium channels (VGCC) or internal calcium stores. In addition, APP affects the expression of survival- or apoptosis-related genes as well as neurotrophic factors. In this review, we summarize the current understanding of the neuroprotective role of APP and APPsα and possible implications for future research and new therapeutic strategies. PMID:28210211

  2. International Space Apps Challenge

    NASA Video Gallery

    During the 2013 Space Apps Challenge, space enthusiasts with diverse backgrounds gathered April 20-21 for a collaborative, global problem-solving effort. Held at Kennedy Space Center Visitor Comple...

  3. APP Function and Lipids: A Bidirectional Link

    PubMed Central

    Grimm, Marcus O. W.; Mett, Janine; Grimm, Heike S.; Hartmann, Tobias

    2017-01-01

    Extracellular neuritic plaques, composed of aggregated amyloid-β (Aβ) peptides, are one of the major histopathological hallmarks of Alzheimer’s disease (AD), a progressive, irreversible neurodegenerative disorder and the most common cause of dementia in the elderly. One of the most prominent risk factor for sporadic AD, carrying one or two aberrant copies of the apolipoprotein E (ApoE) ε4 alleles, closely links AD to lipids. Further, several lipid classes and fatty acids have been reported to be changed in the brain of AD-affected individuals. Interestingly, the observed lipid changes in the brain seem not only to be a consequence of the disease but also modulate Aβ generation. In line with these observations, protective lipids being able to decrease Aβ generation and also potential negative lipids in respect to AD were identified. Mechanistically, Aβ peptides are generated by sequential proteolytic processing of the amyloid precursor protein (APP) by β- and γ-secretase. The α-secretase appears to compete with β-secretase for the initial cleavage of APP, preventing Aβ production. All APP-cleaving secretases as well as APP are transmembrane proteins, further illustrating the impact of lipids on Aβ generation. Beside the pathological impact of Aβ, accumulating evidence suggests that Aβ and the APP intracellular domain (AICD) play an important role in regulating lipid homeostasis, either by direct effects or by affecting gene expression or protein stability of enzymes involved in the de novo synthesis of different lipid classes. This review summarizes the current literature addressing the complex bidirectional link between lipids and AD and APP processing including lipid alterations found in AD post mortem brains, lipids that alter APP processing and the physiological functions of Aβ and AICD in the regulation of several lipid metabolism pathways. PMID:28344547

  4. Apps I Have Loved

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2011-01-01

    According to a March estimate from Distimo, there were 653,614 apps in the iPhone, Android, iPad, BlackBerry, and Windows Mobile stores alone. So, is it any wonder that these busy people have found a few that come in handy on the job? Mobile apps are as indispensable to district IT executives as they are becoming in the classroom--for professional…

  5. Endogenous APP accumulates in synapses after BACE1 inhibition.

    PubMed

    Nigam, Saket Milind; Xu, Shaohua; Ackermann, Frauke; Gregory, Joshua A; Lundkvist, Johan; Lendahl, Urban; Brodin, Lennart

    2016-08-01

    BACE1-mediated cleavage of APP is a pivotal step in the production of the Alzheimer related Aβ peptide and inhibitors of BACE1 are currently in clinical development for the treatment of Alzheimer disease (AD). While processing and trafficking of APP has been extensively studied in non-neuronal cells, the fate of APP at neuronal synapses and in response to reduced BACE1 activity has not been fully elucidated. Here we examined the consequence of reduced BACE1 activity on endogenous synaptic APP by monitoring N- and C-terminal APP epitopes by immunocytochemistry. In control rodent primary hippocampal neuron cultures, labeling with antibodies directed to N-terminal APP epitopes showed a significant overlap with synaptic vesicle markers (SV2 or synaptotagmin). In contrast, labeling with antibodies directed to C-terminal epitopes of APP showed only a limited overlap with these proteins. In neurons derived from BACE1-deficient mice, and in control neurons treated with a BACE1 inhibitor, both the N-terminal and the C-terminal APP labeling overlapped significantly with synaptic vesicle markers. Moreover, BACE1 inhibition increased the proximity between the APP C-terminus and SV2 as shown by a proximity ligation assay. These results, together with biochemical observations, indicate that BACE1 can regulate the levels of full-length APP at neuronal synapses.

  6. APP-BP1 inhibits Aβ42 levels by interacting with Presenilin-1

    PubMed Central

    Chen, Yuzhi; Bodles, Angela M; McPhie, Donna L; Neve, Rachael L; Mrak, Robert E; Griffin, W Sue T

    2007-01-01

    Background The β-amyloid precursor protein (APP) is sequentially cleaved by the β- and then γ-secretase to generate the amyloid β-peptides Aβ40 and Aβ42. Increased Aβ42/Aβ40 ratios trigger amyloid plaque formations in Alzheimer's disease (AD). APP binds to APP-BP1, but the biological consequence is not well understood. Results We report that when the endogenous APP-BP1 was suppressed by small interfering RNAs (siRNAs), cell-associated Aβ42 was dramatically increased in APP695 expressing primary neurons. The accumulation of Aβ42 was accompanied by significant increases in APP and APP-CTF in APP-BP1 siRNA expressing neurons. In contrast, APP-BP1 overexpression in primary neurons significantly decreased the levels of Aβ and endogenous APP but not APLPs. We also investigated the potential mechanism of APP-BP1-mediated APP processing. APP-BP1 co-precipitated with Presenilin-1 (PS1) in native rat brain extracts, co-migrated with the γ-secretase components in brain membrane extracts in glycerol gradient centrifugation, and colocalized in primary neurons. Further, the endogenous PS1-CTF was significantly downregulated by APP-BP1 expression. Conclusion Our data suggest that APP-BP1 may inhibit Aβ42 production by interacting with PS1 under physiological conditions. PMID:17286867

  7. Local Crystalline Structure in an Amorphous Protein Dense Phase.

    PubMed

    Greene, Daniel G; Modla, Shannon; Wagner, Norman J; Sandler, Stanley I; Lenhoff, Abraham M

    2015-10-20

    Proteins exhibit a variety of dense phases ranging from gels, aggregates, and precipitates to crystalline phases and dense liquids. Although the structure of the crystalline phase is known in atomistic detail, little attention has been paid to noncrystalline protein dense phases, and in many cases the structures of these phases are assumed to be fully amorphous. In this work, we used small-angle neutron scattering, electron microscopy, and electron tomography to measure the structure of ovalbumin precipitate particles salted out with ammonium sulfate. We found that the ovalbumin phase-separates into core-shell particles with a core radius of ∼2 μm and shell thickness of ∼0.5 μm. Within this shell region, nanostructures comprised of crystallites of ovalbumin self-assemble into a well-defined bicontinuous network with branches ∼12 nm thick. These results demonstrate that the protein gel is comprised in part of nanocrystalline protein.

  8. Local Crystalline Structure in an Amorphous Protein Dense Phase

    PubMed Central

    Greene, Daniel G.; Modla, Shannon; Wagner, Norman J.; Sandler, Stanley I.; Lenhoff, Abraham M.

    2015-01-01

    Proteins exhibit a variety of dense phases ranging from gels, aggregates, and precipitates to crystalline phases and dense liquids. Although the structure of the crystalline phase is known in atomistic detail, little attention has been paid to noncrystalline protein dense phases, and in many cases the structures of these phases are assumed to be fully amorphous. In this work, we used small-angle neutron scattering, electron microscopy, and electron tomography to measure the structure of ovalbumin precipitate particles salted out with ammonium sulfate. We found that the ovalbumin phase-separates into core-shell particles with a core radius of ∼2 μm and shell thickness of ∼0.5 μm. Within this shell region, nanostructures comprised of crystallites of ovalbumin self-assemble into a well-defined bicontinuous network with branches ∼12 nm thick. These results demonstrate that the protein gel is comprised in part of nanocrystalline protein. PMID:26488663

  9. Phase separation in the isolation and purification of membrane proteins.

    PubMed

    Arnold, Thomas; Linke, Dirk

    2007-10-01

    Phase separation is a simple, efficient, and cheap method to purify and concentrate detergent-solubilized membrane proteins. In spite of this, phase separation is not widely used or even known among membrane protein scientists, and ready-to-use protocols are available for only relatively few detergent/membrane protein combinations. Here, we summarize the physical and chemical parameters that influence the phase separation behavior of detergents commonly used for membrane protein studies. Examples for the successful purification of membrane proteins using this method with different classes of detergents are provided. As the choice of the detergent is critical in many downstream applications (e.g., membrane protein crystallization or functional assays), we discuss how new phase separation protocols can be developed for a given detergent buffer system.

  10. Diet and Physical Activity Apps: Perceived Effectiveness by App Users

    PubMed Central

    Egelandsdal, Bjørg; Amdam, Gro V; Almli, Valerie L; Oostindjer, Marije

    2016-01-01

    Background Diet and physical activity apps are two types of health apps that aim to promote healthy eating and energy expenditure through monitoring of dietary intake and physical activity. No clear evidence showing the effectiveness of using these apps to promote healthy eating and physical activity has been previously reported. Objective This study aimed to identify how diet and physical activity (PA) apps affected their users. It also investigated if using apps was associated with changes in diet and PA. Methods First, 3 semi-structured focus group discussions concerning app usability were conducted (15 app users and 8 nonusers; mean age 24.2 years, SD 6.4), including outcome measures such as motivations, experiences, opinions, and adherence. Results from the discussions were used to develop a questionnaire. The questionnaire, which contained questions about behavior changes, app usage, perceived effectiveness, and opinions of app usability, was answered by 500 Norwegians, with a mean age of 25.8 years (SD 5.1). Results App users found diet and PA apps effective in promoting healthy eating and exercising. These apps affected their actions, health consciousness, and self-education about nutrition and PA; and were also a part of their social lives. Over half of the users perceived that apps were effective in assisting them to eat healthily and to exercise more. Diet apps were more effective when they were frequently used and over a long period of time, compared to infrequent or short-term use (P=.01 and P=.02, respectively). Users who used diet and PA apps, perceived apps as more effective than users who only used one type of app (all P<.05). App users were better at maintaining diet and PA behaviors than nonusers (all P<.05). Young adults found apps fun to use, but sometimes time consuming. They wanted apps to be designed to meet their personal expectations. Conclusions App usage influenced action, consciousness, self-education about nutrition and PA, and social

  11. Regulation of global gene expression and cell proliferation by APP

    PubMed Central

    Wu, Yili; Zhang, Si; Xu, Qin; Zou, Haiyan; Zhou, Weihui; Cai, Fang; Li, Tingyu; Song, Weihong

    2016-01-01

    Down syndrome (DS), caused by trisomy of chromosome 21, is one of the most common genetic disorders. Patients with DS display growth retardation and inevitably develop characteristic Alzheimer’s disease (AD) neuropathology, including neurofibrillary tangles and neuritic plaques. The expression of amyloid precursor protein (APP) is increased in both DS and AD patients. To reveal the function of APP and elucidate the pathogenic role of increased APP expression in DS and AD, we performed gene expression profiling using microarray method in human cells overexpressing APP. A set of genes are significantly altered, which are involved in cell cycle, cell proliferation and p53 signaling. We found that overexpression of APP inhibits cell proliferation. Furthermore, we confirmed that the downregulation of two validated genes, PSMA5 and PSMB7, inhibits cell proliferation, suggesting that the downregulation of PSMA5 and PSMB7 is involved in APP-induced cell proliferation impairment. Taken together, this study suggests that APP regulates global gene expression and increased APP expression inhibits cell proliferation. Our study provides a novel insight that APP overexpression may contribute to the growth impairment in DS patients and promote AD pathogenesis by inhibiting cell proliferation including neural stem cell proliferation and neurogenesis. PMID:26936520

  12. Regulation of global gene expression and cell proliferation by APP.

    PubMed

    Wu, Yili; Zhang, Si; Xu, Qin; Zou, Haiyan; Zhou, Weihui; Cai, Fang; Li, Tingyu; Song, Weihong

    2016-03-03

    Down syndrome (DS), caused by trisomy of chromosome 21, is one of the most common genetic disorders. Patients with DS display growth retardation and inevitably develop characteristic Alzheimer's disease (AD) neuropathology, including neurofibrillary tangles and neuritic plaques. The expression of amyloid precursor protein (APP) is increased in both DS and AD patients. To reveal the function of APP and elucidate the pathogenic role of increased APP expression in DS and AD, we performed gene expression profiling using microarray method in human cells overexpressing APP. A set of genes are significantly altered, which are involved in cell cycle, cell proliferation and p53 signaling. We found that overexpression of APP inhibits cell proliferation. Furthermore, we confirmed that the downregulation of two validated genes, PSMA5 and PSMB7, inhibits cell proliferation, suggesting that the downregulation of PSMA5 and PSMB7 is involved in APP-induced cell proliferation impairment. Taken together, this study suggests that APP regulates global gene expression and increased APP expression inhibits cell proliferation. Our study provides a novel insight that APP overexpression may contribute to the growth impairment in DS patients and promote AD pathogenesis by inhibiting cell proliferation including neural stem cell proliferation and neurogenesis.

  13. Quantifying App Store Dynamics: Longitudinal Tracking of Mental Health Apps

    PubMed Central

    Nicholas, Jennifer; Christensen, Helen

    2016-01-01

    Background For many mental health conditions, mobile health apps offer the ability to deliver information, support, and intervention outside the clinical setting. However, there are difficulties with the use of a commercial app store to distribute health care resources, including turnover of apps, irrelevance of apps, and discordance with evidence-based practice. Objective The primary aim of this study was to quantify the longevity and rate of turnover of mental health apps within the official Android and iOS app stores. The secondary aim was to quantify the proportion of apps that were clinically relevant and assess whether the longevity of these apps differed from clinically nonrelevant apps. The tertiary aim was to establish the proportion of clinically relevant apps that included claims of clinical effectiveness. We performed additional subgroup analyses using additional data from the app stores, including search result ranking, user ratings, and number of downloads. Methods We searched iTunes (iOS) and the Google Play (Android) app stores each day over a 9-month period for apps related to depression, bipolar disorder, and suicide. We performed additional app-specific searches if an app no longer appeared within the main search Results On the Android platform, 50% of the search results changed after 130 days (depression), 195 days (bipolar disorder), and 115 days (suicide). Search results were more stable on the iOS platform, with 50% of the search results remaining at the end of the study period. Approximately 75% of Android and 90% of iOS apps were still available to download at the end of the study. We identified only 35.3% (347/982) of apps as being clinically relevant for depression, of which 9 (2.6%) claimed clinical effectiveness. Only 3 included a full citation to a published study. Conclusions The mental health app environment is volatile, with a clinically relevant app for depression becoming unavailable to download every 2.9 days. This poses

  14. Effects of competition on acute phase proteins and lymphocyte subpopulations - oxidative stress markers in eventing horses.

    PubMed

    Valle, E; Zanatta, R; Odetti, P; Traverso, N; Furfaro, A; Bergero, D; Badino, P; Girardi, C; Miniscalco, B; Bergagna, S; Tarantola, M; Intorre, L; Odore, R

    2015-10-01

    The aim of the study was to evaluate markers of the acute phase response (APR) in eventing horses by measuring acute phase proteins (APP) (haptoglobin, Hp, and serum amyloid A, SAA), lysozyme, protein adducts such as pentosidine-like adducts (PENT), malondialdehyde adducts (MDA), hydroxynonenal adducts (HNE) and total advanced glycation/glycoxidation end products (AGEs), complete blood count and lymphocyte subpopulations (CD4+, CD8+ and CD21+) both at rest and at the end of an eventing competition. Blood samples were collected from eight Warmblood horses (medium age 10 ± 3) during an official national 2-day event competition at rest (R) and 10 min after the arrival of the cross-country test on the second day. Exercise caused a significant increase in red blood cell number, haemoglobin, packed cell volume, neutrophils, white blood cell and lymphocyte number; however, these values remained within the normal range. The CD4+ and CD8+ cells significantly increased, whereas the CD21+ lymphocytes decreased; a significant increase in serum SAA, lysozyme and protein carbonyl derivates was also observed. Two-day event causes significant changes in APR markers such as lysozyme, protein carbonyl derivates (HNE, AGEs, PENT) and lymphocyte subpopulations. The data support the hypothesis that 2-day event may alter significantly APR markers. Limitations of the study were the relatively small sample size and sampling time conditioned by the official regulations of the event. Therefore, further studies are needed to investigate the time required for recovery to basal values in order to define the possible effects on the immune function of the athlete horse.

  15. Serum acute phase proteins as biomarkers of pleuritis and cranio-ventral pulmonary consolidation in slaughter-aged pigs.

    PubMed

    Saco, Yolanda; Fraile, Lorenzo; Giménez, Mercè; Alegre, Ana; López-Jimenez, Rosa; Cortey, Martí; Segalés, Joaquim; Bassols, Anna

    2011-08-01

    The purpose of this study was to investigate the relationship between the existence of lung lesions in pigs at slaughter and the concentration of the serum acute phase proteins (APP), haptoglobin (Hp), pig-major acute protein (Pig-MAP) and C-reactive protein (CRP). A total of 24 pig farms were selected out of a larger farm database previously screened to study risk factors associated with pleuritis and cranio-ventral pulmonary consolidation (CVPC) lesions at slaughter-aged pigs in Spain. The farms were classified as "pleuritis negative (P-) or positive (P+)" and as "CVPC negative (M-) or positive (M+)" and divided into four groups according to a 2X2 factorial design (P-M-, P-M+, P+M-, P+M+). Also at slaughter, blood from 20 randomly selected pigs from each farm was collected. Obtained serum samples were used to measure acute phase proteins. All APP concentrations were significantly higher for M+ farms than for M- ones. However, only Hp and Pig-MAP showed significantly higher concentrations for P+ farms than for P- ones. Pig-MAP was the most sensitive biomarker since it was able to clearly discriminate between P-/P+ and M-/M+ groups (p<0.001 in both cases). Hp was an excellent marker for pleuritis and good for CVPC lesions. CRP was able to discriminate for CVPC lesions but not for pleuritis. The present results indicate that Pig-MAP and, possibly Hp, may be used as potential markers to characterise and discriminate respiratory lesions in swine herds at slaughter.

  16. There's an App for that!

    ERIC Educational Resources Information Center

    Dutton, Gail

    2011-01-01

    Important as training the sales force is, mobile training apps are being used for much more. Visual Eyes Inc., for example, has developed training apps for the U.S. military's combat medical teams that detail specific medical procedures, such as controlling hemorrhaging. Other apps, developed for corporations and government agencies, pass along…

  17. Efficiently, Effectively Detecting Mobile App Bugs with AppDoctor

    DTIC Science & Technology

    2014-04-01

    leading to the failure. Once AppDoctor collects a set of bug reports, it runs automated diagnosis to classify reports into bugs and FPs by replaying...convenience the apps bring. A key reason for buggy apps is that they must handle a vast variety of system and user actions such as being randomly killed by...the OS to save resources, but app developers, facing tough competitions, lack time to thor- oughly test these actions. AppDoctor is a system for effi

  18. Three phase partitioning leads to subtle structural changes in proteins.

    PubMed

    Rather, Gulam Mohmad; Gupta, Munishwar Nath

    2013-09-01

    Three phase partitioning consists of precipitation of proteins due to simultaneous presence of ammonium sulphate and t-butanol. The technique has been successfully used for purification and refolding of proteins. There are however indications that the structures of proteins subjected to three phase partitioning are different from native structure of proteins. Taking several proteins, the present work examines the structural changes in proteins by comparing their thermal stabilities, secondary structure contents, surface hydrophobicities, hydrodynamic radii and solubilities in the presence of ammonium sulphate. The results show that while the nature or extent of structural changes may vary, in all the cases the changes are rather subtle and not drastic in nature. Hence, the technique can be safely used for protein purification and refolding.

  19. All in the Family: How the APPs Regulate Neurogenesis

    PubMed Central

    Lazarov, Orly; Demars, Michael P.

    2012-01-01

    Recent intriguing evidence suggests that metabolites of amyloid precursor protein (APP), mutated in familial forms of Alzheimer’s disease (AD), play critical roles in developmental and postnatal neurogenesis. Of note is soluble APPα (sAPPα) that regulates neural progenitor cell proliferation. The APP family encompasses a group of ubiquitously expressed and evolutionarily conserved, type I transmembrane glycoproteins, whose functions have yet to be fully elucidated. APP can undergo proteolytic cleavage by mutually exclusive pathways. The subtle structural differences between metabolites generated in the different pathways, as well as their equilibrium, may be crucial for neuronal function. The implications of this new body of evidence are significant. Miscleavage of APP would readily impact developmental and postnatal neurogenesis, which might contribute to cognitive deficits characterizing Alzheimer’s disease. This review will discuss the implications of the role of the APP family in neurogenesis for neuronal development, cognitive function, and brain disorders that compromise learning and memory, such as AD. PMID:22675290

  20. Second Virial Coefficient As Determined from Protein Phase Behavior.

    PubMed

    Platten, Florian; Hansen, Jan; Wagner, Dana; Egelhaaf, Stefan U

    2016-10-06

    We quantitatively link the macroscopic phase behavior of protein solutions to protein-protein interactions based on a coarse-grained colloidal approach. We exploit the extended law of corresponding states and apply the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory in order to infer the second virial coefficient b2, an integral measure of the interaction potential, from the phase behavior, namely, cloud-point temperature (CPT) measurements under conditions favoring protein crystallization. This determination of b2 yields values that quantitatively agree with the results of static light scattering (SLS) experiments. The strength of the attractions is quantified in terms of an effective Hamaker constant, which accounts for van der Waals attractions as well as non-DLVO forces, such as hydration and hydrophobic interactions. Our approach based on simple lab experiments to determine the CPT in combination with the DLVO theory is expected to facilitate further biophysical research on protein-protein interactions in complex solution environments.

  1. APP-A Novel Player within the Presynaptic Active Zone Proteome.

    PubMed

    Weingarten, Jens; Weingarten, Melanie; Wegner, Martin; Volknandt, Walter

    2017-01-01

    The amyloid precursor protein (APP) was discovered in the 1980s as the precursor protein of the amyloid A4 peptide. The amyloid A4 peptide, also known as A-beta (Aβ), is the main constituent of senile plaques implicated in Alzheimer's disease (AD). In association with the amyloid deposits, increasing impairments in learning and memory as well as the degeneration of neurons especially in the hippocampus formation are hallmarks of the pathogenesis of AD. Within the last decades much effort has been expended into understanding the pathogenesis of AD. However, little is known about the physiological role of APP within the central nervous system (CNS). Allocating APP to the proteome of the highly dynamic presynaptic active zone (PAZ) identified APP as a novel player within this neuronal communication and signaling network. The analysis of the hippocampal PAZ proteome derived from APP-mutant mice demonstrates that APP is tightly embedded in the underlying protein network. Strikingly, APP deletion accounts for major dysregulation within the PAZ proteome network. Ca(2+)-homeostasis, neurotransmitter release and mitochondrial function are affected and resemble the outcome during the pathogenesis of AD. The observed changes in protein abundance that occur in the absence of APP as well as in AD suggest that APP is a structural and functional regulator within the hippocampal PAZ proteome. Within this review article, we intend to introduce APP as an important player within the hippocampal PAZ proteome and to outline the impact of APP deletion on individual PAZ proteome subcommunities.

  2. Oyster Fisheries App

    NASA Technical Reports Server (NTRS)

    Perez Guerrero, Geraldo A.; Armstrong, Duane; Underwood, Lauren

    2015-01-01

    This project is creating a cloud-enabled, HTML 5 web application to help oyster fishermen and state agencies apply Earth science to improve the management of this important natural and economic resource. The Oyster Fisheries app gathers and analyzes environmental and water quality information, and alerts fishermen and resources managers about problems in oyster fishing waters. An intuitive interface based on Google Maps displays the geospatial information and provides familiar interactive controls to the users. Alerts can be tailored to notify users when conditions in specific leases or public fishing areas require attention. The app is hosted on the Amazon Web Services cloud. It is being developed and tested using some of the latest web development tools such as web components and Polymer.

  3. Using surface-bound rubidium ions for protein phasing.

    PubMed

    Korolev, S; Dementieva, I; Sanishvili, R; Minor, W; Otwinowski, Z; Joachimiak, A

    2001-07-01

    Rubidium is a monovalent metal that can be used as a counterion in protein solutions. X-ray anomalous scattering from rubidium ions bound to the protein surface was used for phasing of the crystal structure of the hsp60 apical domain from Thermus thermophilus. Multiple-wavelength anomalous dispersion (MAD) data were collected from a crystal obtained from a solution containing 0.2 M rubidium salt. One molecule of protein (147 amino acids) binds one well ordered and one poorly ordered Rb atom. Phases calculated with the program SHARP were sufficient for automatic tracing and side-chain assignment using the program ARP/wARP. The data show that bound rubidium ions can be used to determine protein structures and to study the interaction of monovalent metal ions with proteins and other macromolecules.

  4. Development of novel solid-phase protein formulations

    NASA Astrophysics Data System (ADS)

    Montalvo Ortiz, Brenda Liz

    Proteins are the next-generation drugs for the treatment of several diseases. However, the number of protein drugs is still limited due to the physical or chemical instability of proteins during processing, formulation, storage, and delivery. The formulation of proteins at the solid state has advantages over liquid state, such as improved stability during long-term storage and delivery and decreases transportation costs. In this dissertation, we developed new solid-phase protein formulations in which the integrity of the protein was not compromised. The long term goal of this research was to use these protein formulations to improve protein stability in drug delivery devices, such as poly(lactic-co-glycolic) acid (PLGA). The first solid-phase protein formulation developed in this investigation was named "glassification". We proposed glassification as an alternative protein dehydration technique to the common used one, lyophilization, because this last method involves a series of steps which are detrimental to protein structure and stability. The glassification method consisted on protein dehydration by the use of organic solvents. As a result of the glassification process a small (micrometer size range) protein solid bead was obtained. The proteins used to study the glassification process were lysozyme (LYS), alpha-chymotrypsin (CHYMO) and horseradish peroxidase (HRP). These studies revealed that the glassification process itself did not alter protein structure and the activity was preserved. Ethyl acetate was the most effective organic solvent for protein glassification because it led to the highest protein residual activity, no insoluble aggregate formation and is a relatively non-toxic solvent, which allow the incorporation of these protein microparticles in PLGA microspheres. The incorporation of spherical HRP microparticles into PLGA microspheres resulted in superior properties when compared with encapsulated lyophilized HRP powder, such as improved release

  5. Phase diagram of a model of the protein amelogenin

    NASA Astrophysics Data System (ADS)

    Haaga, Jason; Pemberton, Elizabeth; Gunton, J. D.; Rickman, J. M.

    2016-08-01

    There has been considerable recent interest in the self-assembly and phase behavior of models of colloidal and protein particles with anisotropic interactions. One example of particular interest is amelogenin, an important protein involved in the formation of dental enamel. Amelogenin is primarily hydrophobic with a 25-residue charged C-terminus tail. This protein undergoes a hierarchical assembly process that is crucial to mineral deposition, and experimental work has demonstrated that the deletion of the C-terminus tail prevents this self-assembly. A simplified model of amelogenin has been proposed in which the protein is treated as a hydrophobic sphere, interacting via the Asakura-Oosawa (AO) potential, with a tethered point charge on its surface. In this paper, we examine the effect of the Coulomb interaction between the point charges in altering the phase diagram of the AO model. For the parameter case specific to amelogenin, we find that the previous in vitro experimental and model conditions correspond to the system being near the low-density edge of the metastable region of the phase diagram. Our study illustrates more generally the importance of understanding the phase diagram for proteins, in that the kinetic pathway for self-assembly and the resulting aggregate morphology depends on the location of the initial state in the phase diagram.

  6. The level of some acute phase proteins, total protein, gamma-globulins and activity of lysozyme in blood plasma of rats supplemented with vitamin E and exposed to ozone.

    PubMed

    Jakubowski, K; Jedlińska-Krakowska, M; Siwicki, A K

    2004-01-01

    In rats exposed for 28 days (5 hours a day) to ozone at a concentration of 0.5 ppm and receiving alpha-tocopherol at doses of 4.5 mg/rat and 15 mg/rat, levels of acute phase proteins (APP)--C-reactive protein (CRP), ceruloplasmin (Cp), total protein, gamma-globulins, and activity of lysozyme in blood serum were studied. The assays were performed in the presence of respective control groups, i.e. rats receiving the same doses of alpha-tocopherol but not exposed to ozone, a group of animals not supplemented with vitamin but exposed to ozone, a group of animals injected with physiological fluid and a control group not subjected to any of the treatments. The study revealed that the ozone-exposed animals had an increased lysozyme activity and a decreased total protein level. However, in rats protected by alpha-tocopherol and exposed to ozone, the concentration of APP, lysozyme activity and total protein were found to be decreased. Similar relationships also occurred in animals receiving alpha-tocopherol and not exposed to ozone.

  7. Tobacco protein separation by aqueous two-phase extraction.

    PubMed

    Balasubramaniam, Deepa; Wilkinson, Carol; Van Cott, Kevin; Zhang, Chenming

    2003-03-07

    Tobacco has long been considered as a host to produce large quantity of high-valued recombinant proteins. However, dealing with large quantities of biomass is a challenge for downstream processing. Aqueous two-phase extraction (ATPE) has been widely used in purifying proteins from various sources. It is a protein-friendly process and can be scaled up easily. In this paper, ATPE was studied for its applicability to recombinant protein purification from tobacco with egg white lysozyme as the model protein. Separate experiments with poly(ethylene glycol) (PEG)-salt-tobacco extract and PEG-salt-lysozyme were carried out to determine the partition behavior of tobacco protein and lysozyme, respectively. Two-level fractional factorial designs were used to study the effects of factors such as, PEG molecular mass, PEG concentration, the concentration of phase forming salt, sodium chloride concentration and pH, on protein partitioning. The results showed that, among the studied systems, PEG-sodium sulfate system was most suitable for lysozyme purification. Detailed experiments were conducted by spiking lysozyme into the tobacco extract. The conditions with highest selectivity of lysozyme over native tobacco protein were determined using a response surface design. The purification factor was further improved by decreasing the phase ratio along the tie line corresponding to the phase compositions with the highest selectivity. Under selected conditions the lysozyme yield was predicted to be 87% with a purification factor of 4 and concentration factor of 14. From this study, ATPE was shown to be suitable for initial protein recovery and partial purification from transgenic tobacco.

  8. LPS-protein aggregation influences protein partitioning in aqueous two-phase micellar systems.

    PubMed

    Lopes, André Moreni; Santos-Ebinuma, Valéria de Carvalho; Novaes, Leticia Celia de Lencastre; Molino, João Vitor Dutra; Barbosa, Leandro Ramos Souza; Pessoa, Adalberto; Rangel-Yagui, Carlota de Oliveira

    2013-07-01

    Lipopolysaccharide endotoxins (LPS) are the most common pyrogenic substances in recombinant peptides and proteins purified from Gram-negative bacteria, such as Escherichia coli. In this respect, aqueous two-phase micellar systems (ATPMS) have already proven to be a good strategy to purify recombinant proteins of pharmaceutical interest and remove high LPS concentrations. In this paper, we review our recent experimental work in protein partitioning in Triton X-114 ATPMS altogether with some new results and show that LPS-protein aggregation can influence both protein and LPS partitioning. Green fluorescent protein (GFPuv) was employed as a model protein. The ATPMS technology proved to be effective for high loads of LPS removal into the micelle-rich phase (%REM(LPS) > 98 %) while GFPuv partitioned preferentially to the micelle-poor phase (K GFP(uv) < 1.00) due to the excluded-volume interactions. However, theoretically predicted protein partition coefficient values were compared with experimentally obtained ones, and good agreement was found only in the absence of LPS. Dynamic light scattering measurements showed that protein-LPS interactions were taking place and influenced the partitioning process. We believe that this phenomenon should be considered in LPS removal employing any kind of aqueous two-phase system. Nonetheless, ATPMS can still be considered as an efficient strategy for high loads of LPS removal, but being aware that the excluded-volume partitioning theory available might overestimate partition coefficient values due to the presence of protein-LPS aggregation.

  9. Calpain Activation in Alzheimer's Model Mice Is an Artifact of APP and Presenilin Overexpression

    PubMed Central

    Saito, Takashi; Matsuba, Yukio; Yamazaki, Naomi; Hashimoto, Shoko

    2016-01-01

    Intraneuronal calcium stimulates the calpain-dependent conversion of p35 to p25, a CDK5 activator. It is widely believed that amyloid β peptide (Aβ) induces this conversion that, in turn, has an essential role in Alzheimer's disease pathogenesis. However, in vivo studies on p25 generation used transgenic mice overexpressing mutant amyloid precursor protein (APP) and presenilin (PS). Here, using single App knock-in mice, we show that p25 generation is an artifact caused by membrane protein overexpression. We show that massive Aβ42 accumulation without overexpression of APP or presenilin does not produce p25, whereas p25 generation occurred with APP/PS overexpression and in postmortem mouse brain. We further support this finding using mice deficient for calpastatin, the sole calpain-specific inhibitor protein. Thus, the intracerebral environment of the APP/PS mouse brain and postmortem brain is an unphysiological state. SIGNIFICANCE STATEMENT We recently estimated using single App knock-in mice that accumulate amyloid β peptide without transgene overexpression that 60% of the phenotypes observed in Alzheimer's model mice overexpressing mutant amyloid precursor protein (APP) or APP and presenilin are artifacts (Saito et al., 2014). The current study further supports this estimate by invalidating key results from papers that were published in Cell. These findings suggest that more than 3000 publications based on APP and APP/PS overexpression must be reevaluated. PMID:27656030

  10. A comparative study of monoclonal antibodies. 1. Phase behavior and protein-protein interactions.

    PubMed

    Lewus, Rachael A; Levy, Nicholas E; Lenhoff, Abraham M; Sandler, Stanley I

    2015-01-01

    Protein phase behavior is involved in numerous aspects of downstream processing, either by design as in crystallization or precipitation processes, or as an undesired effect, such as aggregation. This work explores the phase behavior of eight monoclonal antibodies (mAbs) that exhibit liquid-liquid separation, aggregation, gelation, and crystallization. The phase behavior has been studied systematically as a function of a number of factors, including solution composition and pH, in order to explore the degree of variability among different antibodies. Comparisons of the locations of phase boundaries show consistent trends as a function of solution composition; however, changing the solution pH has different effects on each of the antibodies studied. Furthermore, the types of dense phases formed varied among the antibodies. Protein-protein interactions, as reflected by values of the osmotic second virial coefficient, are used to correlate the phase behavior. The primary findings are that values of the osmotic second virial coefficient are useful for correlating phase boundary locations, though there is appreciable variability among the antibodies in the apparent strengths of the intrinsic protein-protein attraction manifested. However, the osmotic second virial coefficient does not provide a clear basis to predict the type of dense phase likely to result under a given set of solution conditions.

  11. Mobile Apps in Cardiology: Review

    PubMed Central

    2013-01-01

    Background Cardiovascular diseases are the deadliest diseases worldwide, with 17.3 million deaths in 2008 alone. Among them, heart-related deaths are of the utmost relevance; a fact easily proven by the 7.25 million deaths caused by ischemic heart disease alone in that year. The latest advances in smartphones and mHealth have been used in the creation of thousands of medical apps related to cardiology, which can help to reduce these mortality rates. Objective The aim of this paper is to study the literature on mobile systems and applications currently available, as well as the existing apps related to cardiology from the leading app stores and to then classify the results to see what is available and what is missing, focusing particularly on commercial apps. Methods Two reviews have been developed. One is a literature review of mobile systems and applications, retrieved from several databases and systems such as Scopus, PubMed, IEEE Xplore, and Web of Knowledge. The other is a review of mobile apps in the leading app stores, Google play for Android and Apple’s App Store for iOS. Results Search queries up to May 2013 located 406 papers and 710 apps related to cardiology and heart disease. The most researched section in the literature associated with cardiology is related to mobile heart (and vital signs) monitoring systems and the methods involved in the classification of heart signs in order to detect abnormal functions. Other systems with a significant number of papers are mobile cardiac rehabilitation systems, blood pressure measurement, and systems for the detection of heart failure. The majority of apps for cardiology are heart monitors and medical calculators. Other categories with a high number of apps are those for ECG education and interpretation, cardiology news and journals, blood pressure tracking, heart rate monitoring using an external device, and CPR instruction. There are very few guides on cardiac rehabilitation and apps for the management of the

  12. Mobile Videoconferencing Apps for Telemedicine

    PubMed Central

    Liu, Wei-Li; Locatis, Craig; Ackerman, Michael

    2016-01-01

    Abstract Introduction: The quality and performance of several videoconferencing applications (apps) tested on iOS (Apple, Cupertino, CA) and Android™ (Google, Mountain View, CA) mobile platforms using Wi-Fi (802.11), third-generation (3G), and fourth-generation (4G) cellular networks are described. Materials and Methods: The tests were done to determine how well apps perform compared with videoconferencing software installed on computers or with more traditional videoconferencing using dedicated hardware. The rationale for app assessment and the testing methodology are described. Results: Findings are discussed in relation to operating system platform (iOS or Android) for which the apps were designed and the type of network (Wi-Fi, 3G, or 4G) used. The platform, network, and apps interact, and it is impossible to discuss videoconferencing experienced on mobile devices in relation to one of these factors without referencing the others. Conclusions: Apps for mobile devices can vary significantly from other videoconferencing software or hardware. App performance increased over the testing period due to improvements in network infrastructure and how apps manage bandwidth. PMID:26204322

  13. A Year with Google Apps

    ERIC Educational Resources Information Center

    Hastings, Robin

    2010-01-01

    In August 2008, the Missouri River Regional Library (MRRL), where the author serves as information technology coordinator, switched over from an internally hosted Microsoft Exchange email server to the Google Apps product. As the person who led the charge to use Google Apps and the person who actually flipped the switch, he was responsible for…

  14. Serial femtosecond crystallography of soluble proteins in lipidic cubic phase

    DOE PAGES

    Fromme, Raimund; Ishchenko, Andrii; Metz, Markus; ...

    2015-08-04

    Serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs) enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals of membrane proteins are grown and delivered for SFX data collection inside a gel-like membrane-mimetic matrix, known as lipidic cubic phase (LCP), using a special LCP microextrusion injector. Here, it is shown enabling a dramatic reduction in the amount of crystallized protein required for data collection compared with crystals deliveredmore » by liquid injectors. High-quality LCP–SFX data sets were collected for two soluble proteins, lysozyme and phycocyanin, using less than 0.1 mg of each protein.« less

  15. Serial femtosecond crystallography of soluble proteins in lipidic cubic phase

    SciTech Connect

    Fromme, Raimund; Ishchenko, Andrii; Metz, Markus; Chowdhury, Shatabdi Roy; Basu, Shibom; Boutet, Sébastien; Fromme, Petra; White, Thomas A.; Barty, Anton; Spence, John C. H.; Weierstall, Uwe; Liu, Wei; Cherezov, Vadim

    2015-08-04

    Serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs) enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals of membrane proteins are grown and delivered for SFX data collection inside a gel-like membrane-mimetic matrix, known as lipidic cubic phase (LCP), using a special LCP microextrusion injector. Here, it is shown enabling a dramatic reduction in the amount of crystallized protein required for data collection compared with crystals delivered by liquid injectors. High-quality LCP–SFX data sets were collected for two soluble proteins, lysozyme and phycocyanin, using less than 0.1 mg of each protein.

  16. APP modulates KCC2 expression and function in hippocampal GABAergic inhibition.

    PubMed

    Chen, Ming; Wang, Jinzhao; Jiang, Jinxiang; Zheng, Xingzhi; Justice, Nicholas J; Wang, Kun; Ran, Xiangqian; Li, Yi; Huo, Qingwei; Zhang, Jiajia; Li, Hongmei; Lu, Nannan; Wang, Ying; Zheng, Hui; Long, Cheng; Yang, Li

    2017-01-05

    Amyloid precursor protein (APP) is enriched at the synapse, but its synaptic function is still poorly understood. We previously showed that GABAergic short-term plasticity is impaired in App knock-out (App(-/-)) animals, but the precise mechanism by which APP regulates GABAergic synaptic transmission has remained elusive. Using electrophysiological, biochemical, moleculobiological, and pharmacological analysis, here we show that APP can physically interact with KCC2, a neuron-specific K(+)-Cl(-) cotransporter that is essential for Cl(-) homeostasis and fast GABAergic inhibition. APP deficiency results in significant reductions in both total and membrane KCC2 levels, leading to a depolarizing shift in the GABA reversal potential (EGABA). Simultaneous measurement of presynaptic action potentials and inhibitory postsynaptic currents (IPSCs) in hippocampal neurons reveals impaired unitary IPSC amplitudes attributable to a reduction in α1 subunit levels of GABAAR. Importantly, restoration of normal KCC2 expression and function in App(-/-) mice rescues EGABA, GABAAR α1 levels and GABAAR mediated phasic inhibition. We show that APP functions to limit tyrosine-phosphorylation and ubiquitination and thus subsequent degradation of KCC2, providing a mechanism by which APP influences KCC2 abundance. Together, these experiments elucidate a novel molecular pathway in which APP regulates, via protein-protein interaction with KCC2, GABAAR mediated inhibition in the hippocampus.

  17. APP modulates KCC2 expression and function in hippocampal GABAergic inhibition

    PubMed Central

    Chen, Ming; Wang, Jinzhao; Jiang, Jinxiang; Zheng, Xingzhi; Justice, Nicholas J; Wang, Kun; Ran, Xiangqian; Li, Yi; Huo, Qingwei; Zhang, Jiajia; Li, Hongmei; Lu, Nannan; Wang, Ying; Zheng, Hui; Long, Cheng; Yang, Li

    2017-01-01

    Amyloid precursor protein (APP) is enriched at the synapse, but its synaptic function is still poorly understood. We previously showed that GABAergic short-term plasticity is impaired in App knock-out (App-/-) animals, but the precise mechanism by which APP regulates GABAergic synaptic transmission has remained elusive. Using electrophysiological, biochemical, moleculobiological, and pharmacological analysis, here we show that APP can physically interact with KCC2, a neuron-specific K+-Cl- cotransporter that is essential for Cl- homeostasis and fast GABAergic inhibition. APP deficiency results in significant reductions in both total and membrane KCC2 levels, leading to a depolarizing shift in the GABA reversal potential (EGABA). Simultaneous measurement of presynaptic action potentials and inhibitory postsynaptic currents (IPSCs) in hippocampal neurons reveals impaired unitary IPSC amplitudes attributable to a reduction in α1 subunit levels of GABAAR. Importantly, restoration of normal KCC2 expression and function in App-/- mice rescues EGABA, GABAAR α1 levels and GABAAR mediated phasic inhibition. We show that APP functions to limit tyrosine-phosphorylation and ubiquitination and thus subsequent degradation of KCC2, providing a mechanism by which APP influences KCC2 abundance. Together, these experiments elucidate a novel molecular pathway in which APP regulates, via protein-protein interaction with KCC2, GABAAR mediated inhibition in the hippocampus. DOI: http://dx.doi.org/10.7554/eLife.20142.001 PMID:28054918

  18. Selected acute phase proteins and interleukin-6 in systemic lupus erythematosus patients treated with low doses of quinagolide.

    PubMed

    Hrycek, Antoni; Pochopień-Kenig, Grazyna; Scieszka, Joanna

    2007-05-01

    The relationship between endocrine regulation and immune system has recently become the subject of intense investigations. The objective of this study was to determine the extent of selected serum acute phase proteins (APP), IL-6 and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) involvement in systemic lupus erythematosus (SLE) patients during quinagolide therapy. A further aim of this study was to evaluate the relationships between the above mentioned parameters. In 25 SLE patients treated with a low dose of quinagolide (12.5-50 microg per day) and in 25 healthy persons who constituted the control group, serum concentration of C-creative protein (CRP), alpha-1-antitripsin (AAT), ceruloplasmin (CER), IL-6 and prolactin (PRL) were estimated at entry and in patients after 3 months of treatment. Moreover, SLEDAI score was calculated at entry and after 3 months of therapy with quinagolide. IL-6 and PRL levels were significantly higher in SLE group whereas the concentrations of CRP, AAT and CER were higher than in the controls, but without statistical significance. After 3 month therapy statistically significant decrease of serum level of IL-6 and PRL was revealed. Statistically significant lower serum concentration of CER was also obtained after 3 months of therapy whereas serum CRP and AAT concentration was lower compared with the mean pretreatment level but the results did not reach statistical significance. A raised SLEDAI score at entry was significantly reduced after 3 month therapy and positive correlation with PRL level in examined group of patients with SLE was noted at entry. The decreased serum concentration of IL-6, APP and SLEDAI score observed during applied therapy with small dose of quinagolide confirms the hypothesis that quinagolide may become a valuable and safe drug in the therapy of patients with mild SLE.

  19. Selecting "App"ealing and "App"ropriate Book Apps for Beginning Readers

    ERIC Educational Resources Information Center

    Cahill, Maria; McGill-Franzen, Anne

    2013-01-01

    Beginning with a brief rationale for selecting quality digital picture book apps for beginning readers, the authors describe the elements of digital picture books and provide a brief review of the instructional benefits of digital picture book use for beginning readers. They then present a detailed taxonomy for selecting quality picture book apps.…

  20. Functional Roles of the Interaction of APP and Lipoprotein Receptors

    PubMed Central

    Pohlkamp, Theresa; Wasser, Catherine R.; Herz, Joachim

    2017-01-01

    The biological fates of the key initiator of Alzheimer’s disease (AD), the amyloid precursor protein (APP), and a family of lipoprotein receptors, the low-density lipoprotein (LDL) receptor-related proteins (LRPs) and their molecular roles in the neurodegenerative disease process are inseparably interwoven. Not only does APP bind tightly to the extracellular domains (ECDs) of several members of the LRP group, their intracellular portions are also connected through scaffolds like the one established by FE65 proteins and through interactions with adaptor proteins such as X11/Mint and Dab1. Moreover, the ECDs of APP and LRPs share common ligands, most notably Reelin, a regulator of neuronal migration during embryonic development and modulator of synaptic transmission in the adult brain, and Agrin, another signaling protein which is essential for the formation and maintenance of the neuromuscular junction (NMJ) and which likely also has critical, though at this time less well defined, roles for the regulation of central synapses. Furthermore, the major independent risk factors for AD, Apolipoprotein (Apo) E and ApoJ/Clusterin, are lipoprotein ligands for LRPs. Receptors and ligands mutually influence their intracellular trafficking and thereby the functions and abilities of neurons and the blood-brain-barrier to turn over and remove the pathological product of APP, the amyloid-β peptide. This article will review and summarize the molecular mechanisms that are shared by APP and LRPs and discuss their relative contributions to AD. PMID:28298885

  1. Phase transitions in the assembly of multivalent signalling proteins

    SciTech Connect

    Li, Pilong; Banjade, Sudeep; Cheng, Hui-Chun; Kim, Soyeon; Chen, Baoyu; Guo, Liang; Llaguno, Marc; Hollingsworth, Javoris V.; King, David S.; Banani, Salman F.; Russo, Paul S.; Jiang, Qiu-Xing; Nixon, B. Tracy; Rosen, Michael K.

    2013-04-08

    Cells are organized on length scales ranging from angstrom to micrometers. However, the mechanisms by which angstrom-scale molecular properties are translated to micrometer-scale macroscopic properties are not well understood. Here we show that interactions between diverse synthetic, multivalent macromolecules (including multi-domain proteins and RNA) produce sharp liquid-liquid-demixing phase separations, generating micrometer-sized liquid droplets in aqueous solution. This macroscopic transition corresponds to a molecular transition between small complexes and large, dynamic supramolecular polymers. The concentrations needed for phase transition are directly related to the valency of the interacting species. In the case of the actin-regulatory protein called neural Wiskott-Aldrich syndrome protein (N-WASP) interacting with its established biological partners NCK and phosphorylated nephrin1, the phase transition corresponds to a sharp increase in activity towards an actin nucleation factor, the Arp2/3 complex. The transition is governed by the degree of phosphorylation of nephrin, explaining how this property of the system can be controlled to regulatory effect by kinases. The widespread occurrence of multivalent systems suggests that phase transitions may be used to spatially organize and biochemically regulate information throughout biology.

  2. The use of acute phase proteins for monitoring animal health and welfare in the pig production chain: the validation of an immunochromatographic method for the detection of elevated levels of pig-MAP.

    PubMed

    Piñeiro, Matilde; Morales, Joaquín; Vizcaíno, Elena; Murillo, José Alberto; Klauke, Thorsten; Petersen, Brigitte; Piñeiro, Carlos

    2013-11-01

    The serum concentration of acute phase proteins (APPs) increases in the presence of disease or stress, which makes APPs notable parameters for the global assessment of animal health and welfare. A rapid, immunochromatographic test (ICT) for the detection of elevated levels of pig Major Acute-phase Protein (pig-MAP), one of the main APPs in pigs, was evaluated in more than 1400 pig serum samples obtained from commercial farms. The ICT showed a good performance with a relative sensitivity (Sn) and specificity (Sp) of 94 and 97%, respectively, for a threshold of 1.5mg/mL (comparison with ELISA). Differences in the pig-MAP levels and the number of positive samples with the ICT were observed within the season of sampling, farms, and age groups at one farm, according to the presence of disease or lesions. The ICT was also evaluated in blood samples obtained at slaughter in association with the carcase inspection. The results from this study indicate that the ICT may be used for the evaluation of groups of pigs, after analysing one sub-sample of these pigs, and might be a useful tool in routine health and welfare monitoring programmes aimed to improve the quality of pig production.

  3. Role of common and rare APP DNA sequence variants in Alzheimer disease

    PubMed Central

    Hooli, B.V.; Mohapatra, G.; Mattheisen, M.; Parrado, A.R.; Roehr, J.T.; Shen, Y.; Gusella, J.F.; Moir, R.; Saunders, A.J.; Lange, C.; Tanzi, R.E.

    2012-01-01

    Objectives: More than 30 different rare mutations, including copy number variants (CNVs), in the amyloid precursor protein gene (APP) cause early-onset familial Alzheimer disease (EOFAD), whereas the contribution of common APP variants to disease risk remains controversial. In this study we systematically assessed the role of both rare and common APP DNA variants in Alzheimer disease (AD) families. Methods: Families with EOFAD genetically linked to the APP region were screened for missense mutations and locus duplications of APP. Further, using genome-wide DNA microarray data, we examined the APP locus for CNVs in a total of 797 additional early- and late-onset AD pedigrees. Finally, 423 single nucleotide polymorphisms (SNPs) in the APP locus, including 2 promoter polymorphisms previously associated with AD risk, were tested in up to 4,200 individuals from multiplex AD families. Results: Analyses of 8 21q21-linked families revealed one family carrying a nonsynonymous mutation in exon 17 (Val717Leu) and another family with a partially penetrant 3.5-Mb locus duplication encompassing APP. CNV analysis in the APP locus revealed an additional family carrying a fully penetrant 380-kb duplication, merely spanning APP. Last, contrary to previous reports, association analyses of more than 400 different SNPs in or near APP failed to show significant effects on AD risk. Conclusion: Our study shows that APP mutations and locus duplications are a very rare cause of EOFAD and that the contribution of common APP variants to AD susceptibility is insignificant. Furthermore, duplications of APP may not be fully penetrant, possibly indicating the existence of hitherto unknown protective genetic factors. PMID:22491860

  4. Phase Behavior and Phase Structure of Protein-Surfactant-Water Systems.

    PubMed

    Morén; Khan

    1999-10-15

    Phase behavior of oppositely charged ovalbumin-DOTAC and BSA-DOTAC, and similarly charged ovalbumin-SDS, BSA-SDS, lysozyme-DOTAC, and BLG-SDS systems within the concentration range of 20 wt% of both protein and surfactant are examined in water. Aqueous solutions of ovalbumin yield, in succession, precipitation, gel, and solution with increased addition of the surfactant dodecyltrimethylammonium chloride (DOTAC). The stability range of each region is determined. Both isotropic and anisotropic gels are detected. Solutions of bovine serum albumin (BSA) form only a solution phase with oppositely charged DOTAC. One solution phase is also obtained with all similarly charged protein-surfactant systems except the BLG-SDS-water system, which produces a gel phase in addition to a large solution phase. (2)H NMR longitudinal (R(1)) and transverse (R(2)) relaxation rates are determined in solution and gel by following the behavior of selectively deuterated surfactant at the alpha-methylene group next to the surfactant head group for the oppositely charged systems ovalbumin-DOTAC and BSA-DOTAC. Large R(2)-values proved the existence of large protein-surfactant aggregates in both systems. Copyright 1999 Academic Press.

  5. Acute phase protein response in the capybara (Hydrochoerus hydrochaeris).

    PubMed

    Bernal, Luis; Feser, Mariane; Martínez-Subiela, Silvia; García-Martínez, Juan D; Cerón, José J; Tecles, Fernando

    2011-10-01

    We evaluated the acute phase protein response in capybaras (Hydrochoerus hydrochaeris). Three animal groups were used: 1) healthy animals (n=30), 2) a group in which experimental inflammation with turpentine was induced (n=6), and 3) a group affected with sarcoptic scabies (n=14) in which 10 animals were treated with ivermectin. Haptoglobin (Hp), acid-soluble glycoprotein (ASG) and albumin were analyzed in all animals. In those treated with turpentine, Hp reached its maximum value at 2 wk with a 2.7-fold increase, whereas ASG increased 1.75-fold and albumin decreased 0.87-fold 1 wk after the induction of inflammation. Capybaras affected with sarcoptic scabies presented increases in Hp and ASG of 4.98- and 3.18-fold, respectively, and a 0.87-fold decrease in albumin, compared with healthy animals. Haptoglobin and ASG can be considered as moderate, positive acute phase proteins in capybaras because they showed less than 10-fold increases after an inflammatory process and reached their peak concentrations 1 wk after the induction of inflammation. Conversely, albumin can be considered a negative acute phase protein in capybaras because it showed a reduction in concentration after inflammatory stimulus.

  6. Creating Innovative Student Projects with App Smashing

    ERIC Educational Resources Information Center

    Young, Donna

    2014-01-01

    The potential for using various apps to improve student learning is tremendous. Yet, despite the iPad's possibilities, apps are often limited in their functionality. No one has created that magical, one-size-fits-all app that accomplishes all of the tasks that you had in mind. Luckily, there is an answer to this common problem: app smashing.…

  7. SEC/reversed-phase separation of E. coli proteins.

    PubMed

    Apffell, Alex

    2010-05-01

    Although many chromatographic modes can be coupled for the multidimensional separation of a complex mixture, a very favorable combination is that of size-exclusion chromatography (SEC) and reversed-phase chromatography. The separation mechanisms are largely orthogonal and the mobile phases are compatible. The use of a retentive second dimension allows trapping of specific fractions from the SEC separation and transferring them to the reversed-phase separation. One of the advantages of multidimensional chromatography is that it is scalable in terms of automation. In a completely manual system, fractions eluting from a first dimension can be manually collected and injected into a second separation dimension. In an automated system, fraction transfer can be accomplished through automated valving. The following protocol illustrates this approach, with both a manual method and an external column switching method integrated into an automated high-performance liquid chromatography (HPLC) method. As an illustration, soluble proteins from Escherichia coli are separated.

  8. Serial femtosecond crystallography of soluble proteins in lipidic cubic phase

    SciTech Connect

    Fromme, Raimund; Ishchenko, Andrii; Metz, Markus; Chowdhury, Shatabdi Roy; Basu, Shibom; Boutet, Sébastien; Fromme, Petra; White, Thomas A.; Barty, Anton; Spence, John C. H.; Weierstall, Uwe; Liu, Wei; Cherezov, Vadim

    2015-08-04

    Serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs) enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals of membrane proteins are grown and delivered for SFX data collection inside a gel-like membrane-mimetic matrix, known as lipidic cubic phase (LCP), using a special LCP microextrusion injector. Here, it is demonstrated that LCP can also be used as a suitable carrier medium for microcrystals of soluble proteins, enabling a dramatic reduction in the amount of crystallized protein required for data collection compared with crystals delivered by liquid injectors. High-quality LCP–SFX data sets were collected for two soluble proteins, lysozyme and phycocyanin, using less than 0.1 mg of each protein.

  9. Serial femtosecond crystallography of soluble proteins in lipidic cubic phase

    PubMed Central

    Fromme, Raimund; Ishchenko, Andrii; Metz, Markus; Chowdhury, Shatabdi Roy; Basu, Shibom; Boutet, Sébastien; Fromme, Petra; White, Thomas A.; Barty, Anton; Spence, John C. H.; Weierstall, Uwe; Liu, Wei; Cherezov, Vadim

    2015-01-01

    Serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs) enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals of membrane proteins are grown and delivered for SFX data collection inside a gel-like membrane-mimetic matrix, known as lipidic cubic phase (LCP), using a special LCP microextrusion injector. Here, it is demonstrated that LCP can also be used as a suitable carrier medium for microcrystals of soluble proteins, enabling a dramatic reduction in the amount of crystallized protein required for data collection compared with crystals delivered by liquid injectors. High-quality LCP–SFX data sets were collected for two soluble proteins, lysozyme and phycocyanin, using less than 0.1 mg of each protein. PMID:26306196

  10. The mechanical properties of phase separated protein droplets

    NASA Astrophysics Data System (ADS)

    Jawerth, Louise; Ijavi, Mahdiye; Patel, Avinash; Saha, Shambaditya; Jülicher, Frank; Hyman, Anthony

    In vivo, numerous proteins associate into liquid compartments by de-mixing from the surrounding solution, similar to oil molecules in water. Many of these proteins and their corresponding liquid compartments play a crucial role in important biological processes, for instance germ line specification in C. elegans or in neurodegenerative diseases such as Amyotrophic lateral sclerosis (ALS). However, despite their importance, very little is known about the physical properties of the resulting droplets as well as the physical mechanisms that control their phase separation from solution. To gain a deeper understanding of these aspects, we study a few such proteins in vitro. When these proteins are purified and added to a physiological buffer, they phase separate into droplets ranging in size from a few to tens of microns with liquid-like behavior similar to their physiological counterparts. By attaching small beads to the surface of the droplets, we can deform the droplets by manipulating the beads directly using optical tweezers. By measuring the force required to deform the droplets we determine their surface tension, elasticity and viscosity as well as the frequency response of these properties. We also measure these properties using passive micro-rheology.

  11. Embryonic mosaic deletion of APP results in displaced Reelin-expressing cells in the cerebral cortex.

    PubMed

    Callahan, D G; Taylor, W M; Tilearcio, M; Cavanaugh, T; Selkoe, D J; Young-Pearse, T L

    2017-03-08

    It is widely accepted that amyloid precursor protein (APP) plays a central role in the pathogenesis of Alzheimer's disease. In addition, APP has been proposed to have functions in numerous biological processes including neuronal proliferation, differentiation, migration, axon guidance, and neurite outgrowth, as well as in synapse formation and function. However, germline knockout of APP yields relatively subtle phenotypes, and brain development appears grossly normal. This is thought to be due in part to functional compensation by APP family members and other type I transmembrane proteins. Here, we have generated a conditional mouse knockout for APP that is controlled temporally using Cre(ER) and tamoxifen administration. We show that total cortical expression of APP is reduced following tamoxifen administration during embryonic time points critical for cortical lamination, and that this results in displacement of Reelin-positive cells below the cortical plate with a concurrent elevation in Reelin protein levels. These results support a role for APP in cortical lamination and demonstrate the utility of a conditional knockout approach in which APP can be deleted with temporal control in vivo. This new tool should be useful for many different applications in the study of APP function across the mammalian life span.

  12. Modulation of human neural stem cell differentiation in Alzheimer (APP23) transgenic mice by phenserine.

    PubMed

    Marutle, Amelia; Ohmitsu, Masao; Nilbratt, Mats; Greig, Nigel H; Nordberg, Agneta; Sugaya, Kiminobu

    2007-07-24

    In a previous study, we found that human neural stem cells (HNSCs) exposed to high concentrations of secreted amyloid-precursor protein (sAPP) in vitro differentiated into mainly astrocytes, suggesting that pathological alterations in APP processing during neurodegenerative conditions such as Alzheimer's disease (AD) may prevent neuronal differentiation of HNSCs. Thus, successful neuroplacement therapy for AD may require regulating APP expression to favorable levels to enhance neuronal differentiation of HNSCs. Phenserine, a recently developed cholinesterase inhibitor (ChEI), has been reported to reduce APP levels in vitro and in vivo. In this study, we found reductions of APP and glial fibrillary acidic protein (GFAP) levels in the hippocampus of APP23 mice after 14 days treatment with (+)-phenserine (25 mg/kg) lacking ChEI activity. No significant change in APP gene expression was detected, suggesting that (+)-phenserine decreases APP levels and reactive astrocytes by posttranscription regulation. HNSCs transplanted into (+)-phenserine-treated APP23 mice followed by an additional 7 days of treatment with (+)-phenserine migrated and differentiated into neurons in the hippocampus and cortex after 6 weeks. Moreover, (+)-phenserine significantly increased neuronal differentiation of implanted HNSCs in hippocampal and cortical regions of APP23 mice and in the CA1 region of control mice. These results indicate that (+)-phenserine reduces APP protein in vivo and increases neuronal differentiation of HNSCs. Combination use of HNSC transplantation and treatment with drugs such as (+)-phenserine that modulate APP levels in the brain may be a useful tool for understanding mechanisms regulating stem cell migration and differentiation during neurodegenerative conditions in AD.

  13. APP Is a Context-Sensitive Regulator of the Hippocampal Presynaptic Active Zone.

    PubMed

    Laßek, Melanie; Weingarten, Jens; Wegner, Martin; Mueller, Benjamin F; Rohmer, Marion; Baeumlisberger, Dominic; Arrey, Tabiwang N; Hick, Meike; Ackermann, Jörg; Acker-Palmer, Amparo; Koch, Ina; Müller, Ulrike; Karas, Michael; Volknandt, Walter

    2016-04-01

    The hallmarks of Alzheimer's disease (AD) are characterized by cognitive decline and behavioral changes. The most prominent brain region affected by the progression of AD is the hippocampal formation. The pathogenesis involves a successive loss of hippocampal neurons accompanied by a decline in learning and memory consolidation mainly attributed to an accumulation of senile plaques. The amyloid precursor protein (APP) has been identified as precursor of Aβ-peptides, the main constituents of senile plaques. Until now, little is known about the physiological function of APP within the central nervous system. The allocation of APP to the proteome of the highly dynamic presynaptic active zone (PAZ) highlights APP as a yet unknown player in neuronal communication and signaling. In this study, we analyze the impact of APP deletion on the hippocampal PAZ proteome. The native hippocampal PAZ derived from APP mouse mutants (APP-KOs and NexCreAPP/APLP2-cDKOs) was isolated by subcellular fractionation and immunopurification. Subsequently, an isobaric labeling was performed using TMT6 for protein identification and quantification by high-resolution mass spectrometry. We combine bioinformatics tools and biochemical approaches to address the proteomics dataset and to understand the role of individual proteins. The impact of APP deletion on the hippocampal PAZ proteome was visualized by creating protein-protein interaction (PPI) networks that incorporated APP into the synaptic vesicle cycle, cytoskeletal organization, and calcium-homeostasis. The combination of subcellular fractionation, immunopurification, proteomic analysis, and bioinformatics allowed us to identify APP as structural and functional regulator in a context-sensitive manner within the hippocampal active zone network.

  14. APP Is a Context-Sensitive Regulator of the Hippocampal Presynaptic Active Zone

    PubMed Central

    Mueller, Benjamin F.; Rohmer, Marion; Baeumlisberger, Dominic; Arrey, Tabiwang N.; Hick, Meike; Ackermann, Jörg; Acker-Palmer, Amparo; Koch, Ina; Müller, Ulrike; Karas, Michael; Volknandt, Walter

    2016-01-01

    The hallmarks of Alzheimer’s disease (AD) are characterized by cognitive decline and behavioral changes. The most prominent brain region affected by the progression of AD is the hippocampal formation. The pathogenesis involves a successive loss of hippocampal neurons accompanied by a decline in learning and memory consolidation mainly attributed to an accumulation of senile plaques. The amyloid precursor protein (APP) has been identified as precursor of Aβ-peptides, the main constituents of senile plaques. Until now, little is known about the physiological function of APP within the central nervous system. The allocation of APP to the proteome of the highly dynamic presynaptic active zone (PAZ) highlights APP as a yet unknown player in neuronal communication and signaling. In this study, we analyze the impact of APP deletion on the hippocampal PAZ proteome. The native hippocampal PAZ derived from APP mouse mutants (APP-KOs and NexCreAPP/APLP2-cDKOs) was isolated by subcellular fractionation and immunopurification. Subsequently, an isobaric labeling was performed using TMT6 for protein identification and quantification by high-resolution mass spectrometry. We combine bioinformatics tools and biochemical approaches to address the proteomics dataset and to understand the role of individual proteins. The impact of APP deletion on the hippocampal PAZ proteome was visualized by creating protein-protein interaction (PPI) networks that incorporated APP into the synaptic vesicle cycle, cytoskeletal organization, and calcium-homeostasis. The combination of subcellular fractionation, immunopurification, proteomic analysis, and bioinformatics allowed us to identify APP as structural and functional regulator in a context-sensitive manner within the hippocampal active zone network. PMID:27092780

  15. Urologists' usage and perceptions of urological apps.

    PubMed

    Dempster, Niall J; Risk, Rachel; Clark, Ross; Meddings, Robert N

    2014-12-01

    We conducted a survey of urologists to document their patterns of app usage and perceptions of app quality, and to assess their interest in future app usage. The survey was sent to all urologists on the mailing list of the British Association of Urological Surgeons (BAUS) (n=1613). A total of 115 responses were received (a response rate of 7%). Most respondents (89%) owned mobile devices capable of downloading apps. Most respondents (79%) used apps and about half (49%) used urological apps; the latter accessed a mean of 2.4 urological apps per month. Significantly more younger (defined as <45 years old) than older urologists used urological apps (P<0.001). Respondents' perception of the overall quality of apps produced for both urologists and patients was relatively low. The respondents' interest in future app usage was strong. There was greatest interest in apps such as logbooks or revalidation ones (87%), reference apps (86%) and ones which aided decision-making (85%). There was considerable support for the implementation of measures to provide urological app quality assurance; most respondents believed app peer review (78%) and validation (78%) would be beneficial and 48% supported regulatory oversight. There appears to be a need for high quality urological apps and opportunities therefore exist for national urological associations and academic units to lead developments.

  16. Keratinocytes from APP/APLP2-deficient mice are impaired in proliferation, adhesion and migration in vitro

    SciTech Connect

    Siemes, Christina; Quast, Thomas; Kummer, Christiane; Wehner, Sven; Kirfel, Gregor; Mueller, Ulrike; Herzog, Volker . E-mail: Herzog@uni-bonn.de

    2006-07-01

    Growing evidence shows that the soluble N-terminal form (sAPP{alpha}) of the amyloid precursor protein (APP) represents an epidermal growth factor fostering keratinocyte proliferation, migration and adhesion. APP is a member of a protein family including the two mammalian amyloid precursor-like proteins APLP1 and APLP2. In the mammalian epidermis, only APP and APLP2 are expressed. APP and APLP2-deficient mice die shortly after birth but do not display a specific epidermal phenotype. In this report, we investigated the epidermis of APP and/or APLP2 knockout mice. Basal keratinocytes showed reduced proliferation in vivo by about 40%. Likewise, isolated keratinocytes exhibited reduced proliferation rates in vitro, which could be completely rescued by either exogenously added recombinant sAPP{alpha}, or by co-culture with dermal fibroblasts derived from APP knockout mice. Moreover, APP-knockout keratinocytes revealed reduced migration velocity resulting from severely compromised cell substrate adhesion. Keratinocytes from double knockout mice died within the first week of culture, indicating essential functions of APP-family members for survival in vitro. Our data indicate that sAPP{alpha} has to be considered as an essential epidermal growth factor which, however, in vivo can be functionally compensated to a certain extent by other growth factors, e.g., factors released from dermal fibroblasts.

  17. p95-APP1 links membrane transport to Rac-mediated reorganization of actin.

    PubMed

    Di Cesare, A; Paris, S; Albertinazzi, C; Dariozzi, S; Andersen, J; Mann, M; Longhi, R; de Curtis, I

    2000-08-01

    Motility requires protrusive activity at the cellular edge, where Rho family members regulate actin dynamics. Here we show that p95-APP1 (ArfGAP-putative, Pix-interacting, paxillin-interacting protein 1), a member of the GIT1/PKL family, is part of a complex that interacts with Rac. Wild-type and truncated p95-APP1 induce actin-rich protrusions mediated by Rac and ADP-ribosylation factor 6 (Arf6). Distinct p95-APP1-derived polypeptides have different distributions, indicating that p95-APP1 cycles between the cell surface and endosomes. Our results show that p95-APP1 functionally interacts with Rac and localizes to endosomal compartments, thus identifying p95-APP1 as a molecular link between actin organization, adhesion, and membrane transport during cell motility.

  18. Smartphone Apps for Cardiopulmonary Resuscitation Training and Real Incident Support: A Mixed-Methods Evaluation Study

    PubMed Central

    Felzen, Marc; Rossaint, Rolf; Tabuenca, Bernardo; Specht, Marcus; Skorning, Max

    2014-01-01

    Background No systematic evaluation of smartphone/mobile apps for resuscitation training and real incident support is available to date. To provide medical, usability, and additional quality criteria for the development of apps, we conducted a mixed-methods sequential evaluation combining the perspective of medical experts and end-users. Objective The study aims to assess the quality of current mobile apps for cardiopulmonary resuscitation (CPR) training and real incident support from expert as well as end-user perspective. Methods Two independent medical experts evaluated the medical content of CPR apps from the Google Play store and the Apple App store. The evaluation was based on pre-defined minimum medical content requirements according to current Basic Life Support (BLS) guidelines. In a second phase, non-medical end-users tested usability and appeal of the apps that had at least met the minimum requirements. Usability was assessed with the System Usability Scale (SUS); appeal was measured with the self-developed ReactionDeck toolkit. Results Out of 61 apps, 46 were included in the experts’ evaluation. A consolidated list of 13 apps resulted for the following layperson evaluation. The interrater reliability was substantial (kappa=.61). Layperson end-users (n=14) had a high interrater reliability (intraclass correlation 1 [ICC1]=.83, P<.001, 95% CI 0.75-0.882 and ICC2=.79, P<.001, 95% CI 0.695-0.869). Their evaluation resulted in a list of 5 recommendable apps. Conclusions Although several apps for resuscitation training and real incident support are available, very few are designed according to current BLS guidelines and offer an acceptable level of usability and hedonic quality for laypersons. The results of this study are intended to optimize the development of CPR mobile apps. The app ranking supports the informed selection of mobile apps for training situations and CPR campaigns as well as for real incident support. PMID:24647361

  19. Mastitomics, the integrated omics of bovine milk in an experimental model of Streptococcus uberis mastitis: 1. High abundance proteins, acute phase proteins and peptidomics† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6mb00239k Click here for additional data file.

    PubMed Central

    Thomas, Funmilola Clara; Mullen, William; Tassi, Riccardo; Ramírez-Torres, Adela; Mudaliar, Manikhandan; McNeilly, Tom N.; Zadoks, Ruth N.; Burchmore, Richard

    2016-01-01

    A peptidomic investigation of milk from an experimental model of Streptococcus uberis mastitis in dairy cows has incorporated a study of milk high abundance and acute phase (APP) proteins as well as analysis of low molecular weight peptide biomarkers. Intramammary infection (IMI) with S. uberis caused a shift in abundance from caseins, β-lactoglobulin and α-lactalbumin to albumin, lactoferrin and IgG with the increase in lactoferrin occurring last. The APP response of haptoglobin, mammary associated serum amyloid A3 and C-reactive protein occurred between 30–48 hours post challenge with peak concentrations of APPs at 72–96 hours post challenge and declined thereafter at a rate resembling the fall in bacterial count rather than the somatic cell count. A peptide biomarker panel for IMI based on capillary electrophoresis and mass spectrometry was developed. It comprised 77 identified peptides (IMI77) composed mainly of casein derived peptides but also including peptides of glycosylation dependent cell adhesion molecule and serum amyloid A. The panel had a biomarker classification score that increased from 36 hour to 81 hour post challenge, significantly differentiating infected from non-infected milk, thus suggesting potential as a peptide biomarker panel of bovine mastitis and specifically that of S. uberis origin. The use of omic technology has shown a multifactorial cross system reaction in high and low abundance proteins and their peptide derivatives with changes of over a thousand fold in analyte levels in response to S. uberis infection. PMID:27412456

  20. Serum acute phase proteins in control and Theileria annulata infected water buffaloes (Bubalus bubalis).

    PubMed

    El-Deeb, Wael M; Iacob, Olimpia C

    2012-11-23

    This study was carried out to ascertain the changes in acute phase proteins (APPs) and pro-inflammatory cytokines in Theileria annulata infected water buffalo. Thirty infected water buffaloes and 20 parasitologically free were used. In the present study there was significant (P ≤ 0.05) increase in haptoglobin (Hp), serum amyloid A (SAA), ceruloplasmin, α1-acid glycoprotein (AGP) and fibrinogen levels (2.18 ± 0.29 g/l, 156.58 ± 3.48 mg/l, 31.23 ± 1.25mg/dl, 370.23 ± 33.21 mg/l and 16.17 ± 1.18 g/l, respectively) in T. annulata infected water buffaloes when compared to healthy ones (0.13 ± 0.01 g/l, 23.9 ± 0.56 mg/l, 21.23 ± 1.21 mg/dl, 240.53 ± 22.45 mg/l and 4.2 ± 0.1 6g/l, respectively). Moreover, there was significant (P ≤ 0.05) increase in the levels of TNF-α, IL-1α, IL-6, IL-12, IL-1β and IFN-γ (2.55 ± 0.12 ng/ml, 98.32 ± 4.21 pg/ml, 152.32 ± 5.62 pg/ml, 26.44 ± 1.43 ng/ml, 240.33 ± 20.45 pg/ml and 123.65 ± 5.67 pg/ml, respectively) in T. annulata infected water buffaloes when compared to healthy ones (0.42 ± 0.04 ng/ml, 55.32 ± 3.21 pg/ml, 88.23 ± 3.21 pg/ml, 7.45 ± 0.67 ng/ml, 98.33 ± 3.45 pg/ml and 34.76 ± 1.56 pg/ml, respectively). There was also significant decrease (P ≤ 0.05) in the Hb content, PCV%, RBCs and WBCs counts in the diseased water buffaloes compared to the control ones. Neutropenia, eosinopenia, lymphopenia, monocytopenia and thrombocytopenia were also recorded. The biochemical changes revealed significant (P ≤ 0.05) elevation in the levels of AST, ALT, ALP, LDL-c, VLDL-c, BHBA and NEFA, with significant (P ≤ 0.05) decrease in the levels of total proteins, albumin, globulins, cholesterol, triglyceride, glucose, G6PD, calcium and phosphorus in T. annulata infected water buffaloes when compared to healthy ones. It could be concluded that APPs and pro-inflammatory cytokines could be used as a valuable biomarkers in T. annulata infected water buffaloes (Bubalus bubalis).

  1. APP and APLP2 are essential at PNS and CNS synapses for transmission, spatial learning and LTP

    PubMed Central

    Weyer, Sascha W; Klevanski, Maja; Delekate, Andrea; Voikar, Vootele; Aydin, Dorothee; Hick, Meike; Filippov, Mikhail; Drost, Natalia; Schaller, Kristin L; Saar, Martina; Vogt, Miriam A; Gass, Peter; Samanta, Ayan; Jäschke, Andres; Korte, Martin; Wolfer, David P; Caldwell, John H; Müller, Ulrike C

    2011-01-01

    Despite its key role in Alzheimer pathogenesis, the physiological function(s) of the amyloid precursor protein (APP) and its proteolytic fragments are still poorly understood. Previously, we generated APPsα knock-in (KI) mice expressing solely the secreted ectodomain APPsα. Here, we generated double mutants (APPsα-DM) by crossing APPsα-KI mice onto an APLP2-deficient background and show that APPsα rescues the postnatal lethality of the majority of APP/APLP2 double knockout mice. Surviving APPsα-DM mice exhibited impaired neuromuscular transmission, with reductions in quantal content, readily releasable pool, and ability to sustain vesicle release that resulted in muscular weakness. We show that these defects may be due to loss of an APP/Mint2/Munc18 complex. Moreover, APPsα-DM muscle showed fragmented post-synaptic specializations, suggesting impaired postnatal synaptic maturation and/or maintenance. Despite normal CNS morphology and unaltered basal synaptic transmission, young APPsα-DM mice already showed pronounced hippocampal dysfunction, impaired spatial learning and a deficit in LTP that could be rescued by GABAA receptor inhibition. Collectively, our data show that APLP2 and APP are synergistically required to mediate neuromuscular transmission, spatial learning and synaptic plasticity. PMID:21522131

  2. Psych-related iPhone apps.

    PubMed

    Harrison, Anthony Mark; Goozee, Rhianna

    2014-02-01

    iPhone apps are a widely utilised technology that have recently been identified as a useful medium for health research, clinical interventions and education. While some researchers have discussed advances in app technology, others promote specific apps that are not free to access. To our knowledge, no study has conducted a review of current, free iPhone apps related to psychology, psychiatry and mental health. Therefore, we conducted a pilot, web-based review exploring free iPhone apps using a replicable search strategy within the iTunes Store search function. A selection of apps were selected and subjectively assessed in terms of their usability, utility, graphics, and associated costs for the consumer. We concluded that the apps reviewed, though novel, are limited in their scope and utility. We also note a significant gap in more scientific, evidence-based app technology, and pose some pertinent ethical questions when developing future psych-related apps.

  3. Femtosecond crystallography of membrane proteins in the lipidic cubic phase

    PubMed Central

    Liu, Wei; Wacker, Daniel; Wang, Chong; Abola, Enrique; Cherezov, Vadim

    2014-01-01

    Despite recent technological advances in heterologous expression, stabilization and crystallization of membrane proteins (MPs), their structural studies remain difficult and require new transformative approaches. During the past two years, crystallization in lipidic cubic phase (LCP) has started gaining a widespread acceptance, owing to the spectacular success in high-resolution structure determination of G protein-coupled receptors (GPCRs) and to the introduction of commercial instrumentation, tools and protocols. The recent appearance of X-ray free-electron lasers (XFELs) has enabled structure determination from substantially smaller crystals than previously possible with minimal effects of radiation damage, offering new exciting opportunities in structural biology. The unique properties of LCP material have been exploited to develop special protocols and devices that have established a new method of serial femtosecond crystallography of MPs in LCP (LCP-SFX). In this method, microcrystals are generated in LCP and streamed continuously inside the same media across the intersection with a pulsed XFEL beam at a flow rate that can be adjusted to minimize sample consumption. Pioneering studies that yielded the first room temperature GPCR structures, using a few hundred micrograms of purified protein, validate the LCP-SFX approach and make it attractive for structure determination of difficult-to-crystallize MPs and their complexes with interacting partners. Together with the potential of femtosecond data acquisition to interrogate unstable intermediate functional states of MPs, LCP-SFX holds promise to advance our understanding of this biomedically important class of proteins. PMID:24914147

  4. ACUTE PHASE PROTEIN AND ELECTROPHORESIS PROTEIN FRACTION VALUES FOR CAPTIVE AMERICAN FLAMINGOS (PHOENICOPTERUS RUBER).

    PubMed

    Delk, Katie W; Wack, Raymund F; Burgdorf-Moisuk, Anne; Kass, Philip H; Cray, Carolyn

    2015-12-01

    Protein electrophoresis has recognized applications in determining the health status of various species. While reference intervals for electrophoresis have been determined for psittacine and raptor species, there are none reported for Phoenicopteriformes species. Reference intervals for haptoglobin and protein fractions obtained by electrophoresis were determined for the American flamingo (Phoenicopterus ruber) based on plasma samples from 39 captive birds. The reference intervals were as follows: haptoglobin, 0.17-0.8 mg/ml; total protein, 3.65-6.38 g/dl; prealbumin, 0.26-1.9 g/dl; albumin, 1.51-3.12 g/dl; α-1 globulin, 0.06-0.38 g/dl; α-2 globulin, 0.17-0.67 g/dl; β globulin, 0.38-1.33 g/dl; γ globulin, 0.26-0.68 g/dl; albumin : globulin ratio, 0.93-2.17. As captive flamingos often suffer from pododermatitis, feet of all flamingos were scored to determine if pododermatitis would be reflected in the acute phase proteins. Spearman rank correlation was performed on each of the protein fractions and pododermatitis scores, and only albumin had a significant correlation. This indicates that albumin, as a negative acute phase protein, may be a marker for this disease process.

  5. APP717, APP693, and PRIP gene mutations are rare in Alzheimer disease

    PubMed Central

    Schellenberg, Gerard D.; Anderson, Leojean; O'dahl, Sheldon; Wisjman, Ellen M.; Sadovnick, Adele D.; Ball, Melvyn J.; Larson, Eric B.; Kukull, Walter A.; Martin, George M.; Roses, Allen D.; Bird, Thomas D.

    1991-01-01

    The amyloid precursor protein (APP) gene codes for the precursor to the β-protein found in the amyloid deposits of Alzheimer disease (AD). Recently Goate et al. identified in codon 717 of this gene a missense mutation which segregates with AD in a familial AD (FAD) kindred. The same mutation was also found in affected subjects from a second FAD family but not in other FAD families or in normal controls. The following work was undertaken to determine the frequency of the codon 717 mutation in FAD and nonfamilial AD cases and in normal controls. We tested 76 FAD families, 127 “sporadic” AD subjects, 16 Down syndrome cases, and 256 normal controls for this mutation, and none were positive. We also tested for the APP codon 693 mutation associated with hereditary cerebral hemorrhage with amyloidosis–Dutch type, for PRIP gene missense mutations at codons 102, 117, and 200, and for the PRIP insertion mutations which are associated with Creutzfeld-Jakob disease and Gerstmann-Straussler Scheinker syndrome. No examples of these mutations were found in our population. Thus these APP and PRIP mutations are rare in both FAD and nonfamilial AD. ImagesFigure 1 PMID:1679288

  6. Membrane tethering of APP c-terminal fragments is a prerequisite for T668 phosphorylation preventing nuclear sphere generation.

    PubMed

    Bukhari, Hassan; Kolbe, Katharina; Leonhardt, Gregor; Loosse, Christina; Schröder, Elisabeth; Knauer, Shirley; Marcus, Katrin; Müller, Thorsten

    2016-11-01

    A central molecular hallmark of Alzheimer's disease (AD) is the β- and γ-secretase-mediated cleavage of the amyloid precursor protein (APP), which causes the generation of different c-terminal fragments like C99, AICD57, or AICD50 that fully or in part contain the APP transmembrane domain. In this study, we demonstrate that membrane-tethered C99 is phosphorylated by JNK3A at residue T668 (APP695 numbering) to a higher extent than AICD57, whereas AICD50 is not capable of being phosphorylated. The modification decreases the turnover of APP, while the blockade of APP cleavage increases APP phosphorylation. Generation of nuclear spheres, complexes consisting of the translocated AICD, FE65 and other proteins, is significantly reduced as soon as APP c-terminal fragments are accessible for phosphorylation. This APP modification, which we identified as significantly reduced in high plaque-load areas of the human brain, is linearly dependent on the level of APP expression. Accordingly, we show that APP abundance is likewise capable of modulating nuclear sphere generation. Thus, the precise and complex regulation of APP phosphorylation, abundance, and cleavage impacts the generation of nuclear spheres, which are under discussion of being of relevance in neurodegeneration and dementia. Future pharmacological manipulation of nuclear sphere generation may be a promising approach for AD treatment.

  7. Analysis of Protein Glycosylation and Phosphorylation Using Liquid Phase Separation, Protein Microarray Technology, and Mass Spectrometry

    PubMed Central

    Zhao, Jia; Patwa, Tasneem H.; Pal, Manoj; Qiu, Weilian; Lubman, David M.

    2010-01-01

    Summary Protein glycosylation and phosphorylation are very common posttranslational modifications. The alteration of these modifications in cancer cells is closely related to the onset and progression of cancer and other disease states. In this protocol, strategies for monitoring the changes in protein glycosylation and phosphorylation in serum or tissue cells on a global scale and specifically characterizing these alterations are included. The technique is based on lectin affinity enrichment for glycoproteins, all liquid-phase two-dimensional fractionation, protein microarray, and mass spectrometry technology. Proteins are separated based on pI in the first dimension using chromatofocusing (CF) or liquid isoelectric focusing (IEF) followed by the second-dimension separation using nonporous silica RP-HPLC. Five lectins with different binding specificities to glycan structures are used for screening glycosylation patterns in human serum through a biotin–streptavidin system. Fluorescent phosphodyes and phosphospecific antibodies are employed to detect specific phosphorylated proteins in cell lines or human tissues. The purified proteins of interest are identified by peptide sequencing. Their modifications including glycosylation and phosphorylation could be further characterized by mass-spectrometry-based approaches. These strategies can be used in biological samples for large-scale glycoproteome/phosphoproteome screening as well as for individual protein modification analysis. PMID:19241043

  8. Lipoprotein receptors and cholesterol in APP trafficking and proteolytic processing, implications for Alzheimer’s disease

    PubMed Central

    Marzolo, Maria-Paz; Bu, Guojun

    2009-01-01

    Amyloid-β (Aβ) peptide accumulation in the brain is central to the pathogenesis of Alzheimer’s disease (AD). Aβ is produced through proteolytic processing of a transmembrane protein, β-amyloid precursor protein (APP), by β- and γ-secretases. Mounting evidence has demonstrated that alterations in APP cellular trafficking and localization directly impact its processing to Aβ. Members of the low-density lipoprotein receptor family, including LRP, LRP1B, SorLA/LR11, and apoER2, interact with APP and regulate its endocytic trafficking. Additionally, APP trafficking and processing are greatly affected by cellular cholesterol content. In this review, we summarize the current understanding of the roles of lipoprotein receptors and cholesterol in APP trafficking and processing and their implication for AD pathogenesis and therapy. PMID:19041409

  9. Knockdown of ACAT-1 reduces amyloidogenic processing of APP.

    PubMed

    Huttunen, Henri J; Greco, Christopher; Kovacs, Dora M

    2007-04-17

    Previous studies have shown that acyl-coenzyme A:cholesterol acyl transferase (ACAT), an enzyme that controls cellular equilibrium between free cholesterol and cholesteryl esters, modulates proteolytic processing of APP in cell-based and animal models of Alzheimer's disease. Here we report that ACAT-1 RNAi reduced cellular ACAT-1 protein by approximately 50% and cholesteryl ester levels by 22% while causing a slight increase in the free cholesterol content of ER membranes. This correlated with reduced proteolytic processing of APP and 40% decrease in Abeta secretion. These data show that even a modest decrease in ACAT activity can have robust suppressive effects on Abeta generation.

  10. Visualization of APP and BACE-1 approximation in neurons: new insights into the amyloidogenic pathway

    PubMed Central

    Das, Utpal; Wang, Lina; Ganguly, Archan; Saikia, Junmi M.; Wagner, Steven L.; Koo, Edward H.; Roy, Subhojit

    2016-01-01

    Cleavage of APP (amyloid precursor protein) by BACE-1 (β-site APP cleaving enzyme-1) is the rate-limiting step in amyloid-beta (Aβ) production and a neuropathologic hallmark of Alzheimer's disease (AD); thus physical approximation of this substrate-enzyme pair is a critical event with broad biological and therapeutic implications. Despite much research, neuronal locales of APP/BACE-1 convergence and APP-cleavage remain unclear. Here we report an optical assay – based on fluorescence complementation – to visualize in-cellulo APP/BACE-1 interactions as a simple on/off signal. Combined with other assays tracking the fate of internalized APP in hippocampal neurons, we found that APP/BACE-1 interact in both biosynthetic and endocytic compartments; particularly along recycling-microdomains such as dendritic spines and presynaptic boutons. In axons, APP and BACE-1 are co-transported, and also interact during transit. Finally, our assay reveals that the AD-protective “Icelandic” mutation greatly attenuates APP/BACE-1 interactions, suggesting a mechanistic basis for protection. Collectively, the data challenge canonical models and provide concrete insights into long-standing controversies in the field. PMID:26642089

  11. Inhibition of neuronal calcium oscillations by cell surface APP phosphorylated on T668.

    PubMed

    Santos, Susana Ferrao; Tasiaux, Bernadette; Sindic, Christian; Octave, Jean-Noël

    2011-12-01

    Adenoviral expression of human APP (hAPP), but not of hAPP deleted from its C-terminal intracellular domain, in rat cortical neurons abolishes spontaneous synchronous calcium oscillations. The intracellular domain of APP695 contains several residues that can be phosphorylated. Contrary to non-neuronal cells, a very high phosphorylation of APP on T668 is observed in neurons, which is mediated by JNK, GSK3 and Cdk5 protein kinases. JNK activity, modulated by GSK3, enhances the traffic of phosphorylated APP to nerve terminals, contrary to Cdk5. Here we show that inhibition of GSK3 and JNK restores calcium oscillations in an hAPP expressing neuronal network, whereas inhibition of Cdk5 does not. Expression of mutant hAPPT668A does not inhibit calcium oscillations, and the proportion of hAPPT668A at the plasma membrane is reduced by more than 50%. Altogether, these results indicate that the intracellular domain of APP is needed to inhibit neuronal calcium oscillations because GSK3/JNK phosphorylation of T668 controls APP trafficking at the plasma membrane.

  12. The ionic liquid isopropylammonium formate as a mobile phase modifier to improve protein stability during reversed phase liquid chromatography.

    PubMed

    Zhou, Ling; Danielson, Neil D

    2013-12-01

    The room temperature ionic liquid isopropylammonium formate (IPAF) is studied as a reversed phase HPLC mobile phase modifier for separation of native proteins using a polymeric column and the protein stability is compared to that using acetonitrile (MeCN) as the standard organic mobile phase modifier. A variety of important proteins with different numbers of subunits are investigated, including non-subunit proteins: albumin, and amyloglucosidase (AMY); a two subunit protein: thyroglobulin (THY); and four subunit proteins: glutamate dehydrogenase (GDH) and lactate dehydrogenase (LDH). A significant enhancement in protein stability is observed in the chromatograms upon using IPAF as a mobile phase modifier. The first sharper peak at about 2min represented protein in primarily the native form and a second broader peak more retained at about 5-6min represented substantially denatured or possibly aggregated protein. The investigated proteins (except LDH) could maintain the native form within up to 50% IPAF, while a mobile phase, with as low as 10% MeCN, induced protein denaturation. The assay for pyruvate using LDH has further shown that enzymatic activity can be maintained up to 30% IPAF in water in contrast to no activity using 30% MeCN.

  13. Novel Insights into the Physiological Function of the APP (Gene) Family and Its Proteolytic Fragments in Synaptic Plasticity.

    PubMed

    Ludewig, Susann; Korte, Martin

    2016-01-01

    The amyloid precursor protein (APP) is well known to be involved in the pathophysiology of Alzheimer's disease (AD) via its cleavage product amyloid ß (Aß). However, the physiological role of APP, its various proteolytic products and the amyloid precursor-like proteins 1 and 2 (APLP1/2) are still not fully clarified. Interestingly, it has been shown that learning and memory processes represented by functional and structural changes at synapses are altered in different APP and APLP1/2 mouse mutants. In addition, APP and its fragments are implicated in regulating synaptic strength further reinforcing their modulatory role at the synapse. While APLP2 and APP are functionally redundant, the exclusively CNS expressed APLP1, might have individual roles within the synaptic network. The proteolytic product of non-amyloidogenic APP processing, APPsα, emerged as a neurotrophic peptide that facilitates long-term potentiation (LTP) and restores impairments occurring with age. Interestingly, the newly discovered η-secretase cleavage product, An-α acts in the opposite direction, namely decreasing LTP. In this review we summarize recent findings with emphasis on the physiological role of the APP gene family and its proteolytic products on synaptic function and plasticity, especially during processes of hippocampal LTP. Therefore, we focus on literature that provide electrophysiological data by using different mutant mouse strains either lacking full-length or parts of the APP proteins or that utilized secretase inhibitors as well as secreted APP fragments.

  14. Novel Insights into the Physiological Function of the APP (Gene) Family and Its Proteolytic Fragments in Synaptic Plasticity

    PubMed Central

    Ludewig, Susann; Korte, Martin

    2017-01-01

    The amyloid precursor protein (APP) is well known to be involved in the pathophysiology of Alzheimer's disease (AD) via its cleavage product amyloid ß (Aß). However, the physiological role of APP, its various proteolytic products and the amyloid precursor-like proteins 1 and 2 (APLP1/2) are still not fully clarified. Interestingly, it has been shown that learning and memory processes represented by functional and structural changes at synapses are altered in different APP and APLP1/2 mouse mutants. In addition, APP and its fragments are implicated in regulating synaptic strength further reinforcing their modulatory role at the synapse. While APLP2 and APP are functionally redundant, the exclusively CNS expressed APLP1, might have individual roles within the synaptic network. The proteolytic product of non-amyloidogenic APP processing, APPsα, emerged as a neurotrophic peptide that facilitates long-term potentiation (LTP) and restores impairments occurring with age. Interestingly, the newly discovered η-secretase cleavage product, An-α acts in the opposite direction, namely decreasing LTP. In this review we summarize recent findings with emphasis on the physiological role of the APP gene family and its proteolytic products on synaptic function and plasticity, especially during processes of hippocampal LTP. Therefore, we focus on literature that provide electrophysiological data by using different mutant mouse strains either lacking full-length or parts of the APP proteins or that utilized secretase inhibitors as well as secreted APP fragments. PMID:28163673

  15. User Preferences for Content, Features, and Style for an App to Reduce Harmful Drinking in Young Adults: Analysis of User Feedback in App Stores and Focus Group Interviews

    PubMed Central

    Khadjesari, Zarnie; Fincham-Campbell, Stephanie; Deluca, Paolo; Watson, Rod; Drummond, Colin

    2016-01-01

    Background Electronic screening and brief intervention (eSBI) is effective in reducing weekly alcohol consumption when delivered by a computer. Mobile phone apps demonstrate promise in delivering eSBI; however, few have been designed with an evidence-based and user-informed approach. Objective This study aims to explore from a user perspective, preferences for content, appearance, and operational features to inform the design of a mobile phone app for reducing quantity and frequency of drinking in young adults engaged in harmful drinking (18-30 year olds). Methods Phase 1 included a review of user reviews of available mobile phone apps that support a reduction in alcohol consumption. Apps were identified on iTunes and Google Play and were categorized into alcohol reduction support, entertainment, blood alcohol content measurement (BAC), or other. eSBI apps with ≥18 user reviews were subject to a content analysis, which coded praise, criticism, and recommendations for app content, functionality, and esthetics. Phase 2 included four focus groups with young adults drinking at harmful levels and residing in South London to explore their views on existing eSBI apps and preferences for future content, functionality, and appearance. Detailed thematic analysis of the data was undertaken. Results In Phase 1, of the 1584 apps extracted, 201 were categorized as alcohol reduction, 154 as BAC calculators, 509 as entertainment, and 720 as other. We classified 32 apps as eSBI apps. Four apps had ≥18 user reviews: Change for Life Drinks Tracker, Drinksmeter, Drinkaware, and Alcohol Units Calculator. The highest proportion of content praises were for information and feedback provided in the apps (12/27, 44%), followed by praise for the monitoring features (5/27, 19%). Many (8/12, 67%) criticisms were for the drinking diary; all of these were related to difficulty entering drinks. Over half (18/32, 56%) of functionality criticisms were descriptions of software bugs, and over

  16. Cannabis Mobile Apps: A Content Analysis

    PubMed Central

    Popova, Lucy; Grana, Rachel; Zhao, Shirley; Chavez, Kathryn

    2015-01-01

    Background Mobile technology is pervasive and widely used to obtain information about drugs such as cannabis, especially in a climate of rapidly changing cannabis policy; yet the content of available cannabis apps is largely unknown. Understanding the resources available to those searching for cannabis apps will clarify how this technology is being used to reflect and influence cannabis use behavior. Objective We investigated the content of 59 cannabis-related mobile apps for Apple and Android devices as of November 26, 2014. Methods The Apple and Google Play app stores were searched using the terms “cannabis” and “marijuana.” Three trained coders classified the top 20 apps for each term and each store, using a coding guide. Apps were examined for the presence of 20 content codes derived by the researchers. Results Total apps available for each search term were 124 for cannabis and 218 for marijuana in the Apple App Store, and 250 each for cannabis and marijuana on Google Play. The top 20 apps in each category in each store were coded for 59 independent apps (30 Apple, 29 Google Play). The three most common content areas were cannabis strain classification (33.9%), facts about cannabis (20.3%), and games (20.3%). In the Apple App Store, most apps were free (77%), all were rated “17+” years, and the average user rating was 3.9/5 stars. The most popular apps provided cannabis strain classifications (50%), dispensary information (27%), or general facts about cannabis (27%). Only one app (3%) provided information or resources related to cannabis abuse, addiction, or treatment. On Google Play, most apps were free (93%), rated “high maturity” (79%), and the average user rating was 4.1/5. The most popular app types offered games (28%), phone utilities (eg, wallpaper, clock; 21%) and cannabis food recipes (21%); no apps addressed abuse, addiction, or treatment. Conclusions Cannabis apps are generally free and highly rated. Apps were most often informational

  17. An AICD-based functional screen to identify APP metabolism regulators

    PubMed Central

    Zhang, Can; Khandelwal, Preeti J; Chakraborty, Ranjita; Cuellar, Trinna L; Sarangi, Srikant; Patel, Shyam A; Cosentino, Christopher P; O'Connor, Michael; Lee, Jeremy C; Tanzi, Rudolph E; Saunders, Aleister J

    2007-01-01

    Background A central event in Alzheimer's disease (AD) is the regulated intramembraneous proteolysis of the β-amyloid precursor protein (APP), to generate the β-amyloid (Aβ) peptide and the APP intracellular domain (AICD). Aβ is the major component of amyloid plaques and AICD displays transcriptional activation properties. We have taken advantage of AICD transactivation properties to develop a genetic screen to identify regulators of APP metabolism. This screen relies on an APP-Gal4 fusion protein, which upon normal proteolysis, produces AICD-Gal4. Production of AICD-Gal4 induces Gal4-UAS driven luciferase expression. Therefore, when regulators of APP metabolism are modulated, luciferase expression is altered. Results To validate this experimental approach we modulated α-, β-, and γ-secretase levels and activities. Changes in AICD-Gal4 levels as measured by Western blot analysis were strongly and significantly correlated to the observed changes in AICD-Gal4 mediated luciferase activity. To determine if a known regulator of APP trafficking/maturation and Presenilin1 endoproteolysis could be detected using the AICD-Gal4 mediated luciferase assay, we knocked-down Ubiquilin 1 and observed decreased luciferase activity. We confirmed that Ubiquilin 1 modulated AICD-Gal4 levels by Western blot analysis and also observed that Ubiquilin 1 modulated total APP levels, the ratio of mature to immature APP, as well as PS1 endoproteolysis. Conclusion Taken together, we have shown that this screen can identify known APP metabolism regulators that control proteolysis, intracellular trafficking, maturation and levels of APP and its proteolytic products. We demonstrate for the first time that Ubiquilin 1 regulates APP metabolism in the human neuroblastoma cell line, SH-SY5Y. PMID:17718916

  18. Smartphone use in neurosurgery? APP-solutely!

    PubMed Central

    Zaki, Michael; Drazin, Doniel

    2014-01-01

    Background: A number of smartphone medical apps have recently emerged that may be helpful for the neurosurgical patient, practitioner, and trainee. This study aims to review the current neurosurgery-focused apps available for the iPhone, iPad, and Android platforms as of December 2013. Methods: Two of the most popular smartphone app stores (Apple Store and Android Google Play Store) were surveyed for neurosurgery-focused apps in December 2013. Search results were categorized based on their description page. Data were collected on price, rating, app release date, target audience, and medical professional involvement in app design. A review of the top apps in each category was performed. Results: The search resulted in 111 unique apps, divided into these 7 categories: 16 (14%) clinical tools, 17 (15%) conference adjunct, 27 (24%) education, 18 (16%) literature, 15 (14%) marketing, 10 (9%) patient information, and 8 (7%) reference. The average cost of paid apps was $23.06 (range: $0.99-89.99). Out of the 111 apps, 71 (64%) were free, 48 (43%) had reviews, and 14 (13%) had more than 10 reviews. Seventy-three (66%) apps showed evidence of medical professional involvement. The number of apps being released every year has been increasing since 2009. Conclusions: There are a number of neurosurgery-themed apps available to all audiences. There was a lack of patient information apps for nonspinal procedures. Most apps did not have enough reviews to evaluate their quality. There was also a lack of oversight to validate the accuracy of medical information provided in these apps. PMID:25101208

  19. Acute phase proteins in Andalusian horses infected with Theileria equi.

    PubMed

    Rodríguez, Rocío; Cerón, José J; Riber, Cristina; Castejón, Francisco; Gómez-Díez, Manuel; Serrano-Rodríguez, Juan M; Muñoz, Ana

    2014-10-01

    Clinical and laboratory findings were determined in 23 Andalusian horses in southern Spain that were positive for Theileria equi by PCR, including 16 mares at pasture (group A1) and seven stabled stallions (group B1). Five healthy mares at pasture (group A2) and five stabled stallions (group B2), all of which were negative for T. equi in Giemsa stained blood smears and by PCR, were used as controls. The most frequent clinical signs were anorexia, anaemia, depression and icterus (group A1), along with loss of performance or failure to train and depression (group B1). Thrombocytopoenia was evident in 5/7 horses in group B1. Lower serum iron concentrations were observed in both diseased groups compared with their respective control groups. There were no significant differences in APP concentrations between diseased and control groups; all affected horses had APP concentrations within reference limits. Serum haptoglobin, serum amyloid A and plasma fibrinogen concentrations were higher than the reference limits in 5/23, 3/23 and 1/23 diseased horses, respectively. It was concluded that horses with theileriosis exhibited only a mild systemic inflammatory response.

  20. Color Addition and Subtraction Apps

    ERIC Educational Resources Information Center

    Ruiz, Frances; Ruiz, Michael J.

    2015-01-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…

  1. Illuminating Apps for Fourth Grade

    ERIC Educational Resources Information Center

    Lennex, Lesia; Bodenlos, Emily

    2014-01-01

    Elementary science is chock-full of wonderful experiences for students. Do children see iPads as a tool for learning about science? Using Prensky (2010) as a guide, the researchers decided to see if "assessing students with their own" tools (p.178) using iPad apps would support learning discrete knowledge for electricity and light…

  2. 15 CFR 740.7 - Computers (APP).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false Computers (APP). 740.7 Section 740.7... Computers (APP). (a) Scope—(1) Commodities. License Exception APP authorizes exports and reexports of computers, including “electronic assemblies” and specially designed components therefor controlled by...

  3. 15 CFR 740.7 - Computers (APP).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Computers (APP). 740.7 Section 740.7... Computers (APP). (a) Scope—(1) Commodities. License Exception APP authorizes exports and reexports of computers, including “electronic assemblies” and specially designed components therefor controlled by...

  4. 15 CFR 740.7 - Computers (APP).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false Computers (APP). 740.7 Section 740.7... Computers (APP). (a) Scope—(1) Commodities. License Exception APP authorizes exports and reexports of computers, including “electronic assemblies” and specially designed components therefor controlled by...

  5. 15 CFR 740.7 - Computers (APP).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false Computers (APP). 740.7 Section 740.7... Computers (APP). (a) Scope—(1) Commodities. License Exception APP authorizes exports and reexports of computers, including “electronic assemblies” and specially designed components therefor controlled by...

  6. Capitalizing on App Development Tools and Technologies

    ERIC Educational Resources Information Center

    Luterbach, Kenneth J.; Hubbell, Kenneth R.

    2015-01-01

    Instructional developers and others creating apps must choose from a wide variety of app development tools and technologies. Some app development tools have incorporated visual programming features, which enable some drag and drop coding and contextual programming. While those features help novices begin programming with greater ease, questions…

  7. Novel N-terminal cleavage of APP precludes Abeta generation in ACAT-defective AC29 cells.

    PubMed

    Huttunen, Henri J; Puglielli, Luigi; Ellis, Blake C; MacKenzie Ingano, Laura A; Kovacs, Dora M

    2009-01-01

    A common pathogenic event that occurs in all forms of Alzheimer's disease is the progressive accumulation of amyloid beta-peptide (Abeta) in brain regions responsible for higher cognitive functions. Inhibition of acyl-coenzyme A: cholesterol acyltransferase (ACAT), which generates intracellular cholesteryl esters from free cholesterol and fatty acids, reduces the biogenesis of the Abeta from the amyloid precursor protein (APP). Here we have used AC29 cells, defective in ACAT activity, to show that ACAT activity steers APP either toward or away from a novel proteolytic pathway that replaces both alpha and the amyloidogenic beta cleavages of APP. This alternative pathway involves a novel cleavage of APP holoprotein at Glu281, which correlates with reduced ACAT activity and Abeta generation in AC29 cells. This sterol-dependent cleavage of APP occurs in the endosomal compartment after internalization of cell surface APP. The resulting novel C-terminal fragment APP-C470 is destined to proteasomal degradation limiting the availability of APP for the Abeta generating system. The proportion of APP molecules that are directed to the novel cleavage pathway is regulated by the ratio of free cholesterol and cholesteryl esters in cells. These results suggest that subcellular cholesterol distribution may be an important regulator of the cellular fate of APP holoprotein and that there may exist several competing proteolytic systems responsible for APP processing within the endosomal compartment.

  8. APP-dependent glial cell line-derived neurotrophic factor gene expression drives neuromuscular junction formation.

    PubMed

    Stanga, Serena; Zanou, Nadège; Audouard, Emilie; Tasiaux, Bernadette; Contino, Sabrina; Vandermeulen, Gaëlle; René, Frédérique; Loeffler, Jean-Philippe; Clotman, Frédéric; Gailly, Philippe; Dewachter, Ilse; Octave, Jean-Noël; Kienlen-Campard, Pascal

    2016-05-01

    Besides its crucial role in the pathogenesis of Alzheimer's disease, the knowledge of amyloid precursor protein (APP) physiologic functions remains surprisingly scarce. Here, we show that APP regulates the transcription of the glial cell line-derived neurotrophic factor (GDNF). APP-dependent regulation of GDNF expression affects muscle strength, muscular trophy, and both neuronal and muscular differentiation fundamental for neuromuscular junction (NMJ) maturation in vivo In a nerve-muscle coculture model set up to modelize NMJ formation in vitro, silencing of muscular APP induces a 30% decrease in secreted GDNF levels and a 40% decrease in the total number of NMJs together with a significant reduction in the density of acetylcholine vesicles at the presynaptic site and in neuronal maturation. These defects are rescued by GDNF expression in muscle cells in the conditions where muscular APP has been previously silenced. Expression of GDNF in muscles of amyloid precursor protein null mice corrected the aberrant synaptic morphology of NMJs. Our findings highlight for the first time that APP-dependent GDNF expression drives the process of NMJ formation, providing new insights into the link between APP gene regulatory network and physiologic functions.-Stanga, S., Zanou, N., Audouard, E., Tasiaux, B., Contino, S., Vandermeulen, G., René, F., Loeffler, J.-P., Clotman, F., Gailly, P., Dewachter, I., Octave, J.-N., Kienlen-Campard, P. APP-dependent glial cell line-derived neurotrophic factor gene expression drives neuromuscular junction formation.

  9. Loss of presenilin function is associated with a selective gain of APP function.

    PubMed

    Deyts, Carole; Clutter, Mary; Herrera, Stacy; Jovanovic, Natalia; Goddi, Anna; Parent, Angèle T

    2016-05-19

    Presenilin 1 (PS1) is an essential γ-secretase component, the enzyme responsible for amyloid precursor protein (APP) intramembraneous cleavage. Mutations in PS1 lead to dominant-inheritance of early-onset familial Alzheimer's disease (FAD). Although expression of FAD-linked PS1 mutations enhances toxic Aβ production, the importance of other APP metabolites and γ-secretase substrates in the etiology of the disease has not been confirmed. We report that neurons expressing FAD-linked PS1 variants or functionally deficient PS1 exhibit enhanced axodendritic outgrowth due to increased levels of APP intracellular C-terminal fragment (APP-CTF). APP expression is required for exuberant neurite outgrowth and hippocampal axonal sprouting observed in knock-in mice expressing FAD-linked PS1 mutation. APP-CTF accumulation initiates CREB signaling cascade through an association of APP-CTF with Gαs protein. We demonstrate that pathological PS1 loss-of-function impinges on neurite formation through a selective APP gain-of-function that could impact on axodendritic connectivity and contribute to aberrant axonal sprouting observed in AD patients.

  10. Relation between the phase separation and the crystallization in protein solutions

    NASA Astrophysics Data System (ADS)

    Tanaka, Shinpei; Yamamoto, Masahiko; Ito, Kohzo; Hayakawa, Reinosuke; Ataka, Mitsuo

    1997-07-01

    Liquid-liquid phase separation and crystallization (or solid-liquid phase separation) both occur in protein solutions. By adopting egg-white lysozyme for a model system, we compared two types of diagrams, a phase diagram of the liquid-liquid phase separation and a morphological diagram of protein crystals. By superimposing these diagrams, we distinguished two types of white precipitates, urchinlike spherulites arising from the crystallization and protein-rich droplets from the liquid-liquid phase separation. Furthermore, we observed a transformation from the protein-rich droplets to the spherulites, and simultaneously an unusual pattern evolution of the protein-rich phase unlike the conventional phase separation of typical binary mixtures. This is understood in terms of the competition between the crystallization and the liquid-liquid phase separation.

  11. Transport proteins and acute phase reactant proteins in children with sickle cell anemia.

    PubMed Central

    Warrier, R. P.; Kuvibidila, S.; Gordon, L.; Humbert, J.

    1994-01-01

    Transport proteins, acute-phase reactant proteins (APRP), hematology, and anthropometry were studied in 34 sickle cell disease (SCD) children (20 boys, 14 girls) and 27 controls without growth deficits (13 boys, 14 girls) [corrected]. The age range was 1/2 to 16 1/2 years. Weight deficits (< 80%) by Waterlow's classification were observed in 41% of SCD boys and 25% of SCD girls, and height deficits (< 90%) were observed in 25% SCD boys and 25% girls. Mean white blood cell counts were significantly higher (P < .001) and hematocrit and hemoglobin (Hb) lower (P < .005) in SCD children than in controls. Although both groups had similar mean levels of albumin, transferrin, and APRP, SCD children had significantly lower mean levels of retinol-binding protein (RBP) (P < .001) and retinol-prealbumin (P < .001). Retinol-binding protein levels were abnormal in 18 (53%) SCD children and in only 23% controls (chi 2 = 14.06; P < 0.005); transferrin levels were abnormal in 20% of SCD children and in none of the controls. Children with SC and SF Hb phenotype had normal mean levels of RBP, whereas those with S beta thal and SS phenotype had levels below normal. Growth-retarded children by weight and height had reduced mean levels of RBP and prealbumin compared with growth-normal SCD children. The implication of primary protein-energy malnutrition on growth retardation in SCD children is under study. PMID:7512147

  12. Heat shock protein coinducers with no effect on protein denaturation specifically modulate the membrane lipid phase

    PubMed Central

    Török, Zsolt; Tsvetkova, Nelly M.; Balogh, Gábor; Horváth, Ibolya; Nagy, Enikő; Pénzes, Zoltán; Hargitai, Judit; Bensaude, Olivier; Csermely, Péter; Crowe, John H.; Maresca, Bruno; Vígh, László

    2003-01-01

    The hydroxylamine derivative bimoclomol (BM) has been shown to activate natural cytoprotective homeostatic responses by enhancing the capability of cells to cope with various pathophysiological conditions. It exerts its effect in synergy with low levels of stress to induce the synthesis of members of major stress protein families. We show here that the presence of BM does not influence protein denaturation in the cells. BM and its derivatives selectively interact with acidic lipids and modulate their thermal and dynamic properties. BM acts as a membrane fluidizer at normal temperature, but it is a highly efficient membrane stabilizer, inhibiting the bilayer–nonbilayer phase transitions during severe heat shock. We suggest that BM and the related compounds modify those domains of membrane lipids where the thermally or chemically induced perturbation of lipid phase is sensed and transduced into a cellular signal, leading to enhanced activation of heat shock genes. BM may be a prototype for clinically safe membrane-interacting drug candidates that rebalance the level and composition of heat shock proteins. PMID:12615993

  13. Computational insights into the selectivity mechanism of APP-IP over matrix metalloproteinases.

    PubMed

    Geng, Lingling; Gao, Jian; Cui, Wei; Tang, Yancheng; Ji, Mingjuan; Chen, Bozhen

    2012-12-01

    In this work, selectivity mechanism of APP-IP inhibitor (β-amyloid precursor protein-derived inhibitory peptide) over matrix metalloproteinases (MMPs including MMP-2, MMP-7, MMP-9 and MMP-14) was investigated by molecular modeling methods. Among MMPs, MMP-2 is the most favorable one for APP-IP interacting based on our calculations. The predicted binding affinities can give a good explanation of the activity difference of inhibitor APP-IP. In Comparison with MMP-2/APP-IP complex, the side chain of Tyr214(MMP-7) makes the binding pocket so shallow that the whole side chain of Tyr3(APP-IP) can not be fully embraced, thus unfavorable for the N-terminal of APP-IP binding to MMP-7. The poor selectivity of APP-IP toward MMP-9 is mainly related with the decrease of interaction between the APP-IP C-terminal and MMP-9 due to the bulky side chains of Pro193 and Gln199, which is in agreement with experiment. The mutations at residues P193A and Q199G of MMP-9 alternate the binding pattern of the C-terminal of APP-IP by forming two new hydrogen bonds and hydrophobic interactions with MMP-9. The mutants favor the binding affinity of MMP-9 largely. For MMP-14/APP-IP, the large steric effect of Phe204(MMP-14) and the weak contributions of the polar residues Asn231(MMP-14) and Thr190(MMP-14) could explain why MMP-14 is non-selective for APP-IP interacting. Here, the molecular modeling methods were successfully employed to explore the selective inhibitor of MMPs, and our work gives valuable information for future rational design of selective peptide inhibitors toward individual MMP.

  14. Sequence heuristics to encode phase behaviour in intrinsically disordered protein polymers

    PubMed Central

    Quiroz, Felipe García; Chilkoti, Ashutosh

    2015-01-01

    Proteins and synthetic polymers that undergo aqueous phase transitions mediate self-assembly in nature and in man-made material systems. Yet little is known about how the phase behaviour of a protein is encoded in its amino acid sequence. Here, by synthesizing intrinsically disordered, repeat proteins to test motifs that we hypothesized would encode phase behaviour, we show that the proteins can be designed to exhibit tunable lower or upper critical solution temperature (LCST and UCST, respectively) transitions in physiological solutions. We also show that mutation of key residues at the repeat level abolishes phase behaviour or encodes an orthogonal transition. Furthermore, we provide heuristics to identify, at the proteome level, proteins that might exhibit phase behaviour and to design novel protein polymers consisting of biologically active peptide repeats that exhibit LCST or UCST transitions. These findings set the foundation for the prediction and encoding of phase behaviour at the sequence level. PMID:26390327

  15. Sequence heuristics to encode phase behaviour in intrinsically disordered protein polymers.

    PubMed

    Quiroz, Felipe García; Chilkoti, Ashutosh

    2015-11-01

    Proteins and synthetic polymers that undergo aqueous phase transitions mediate self-assembly in nature and in man-made material systems. Yet little is known about how the phase behaviour of a protein is encoded in its amino acid sequence. Here, by synthesizing intrinsically disordered, repeat proteins to test motifs that we hypothesized would encode phase behaviour, we show that the proteins can be designed to exhibit tunable lower or upper critical solution temperature (LCST and UCST, respectively) transitions in physiological solutions. We also show that mutation of key residues at the repeat level abolishes phase behaviour or encodes an orthogonal transition. Furthermore, we provide heuristics to identify, at the proteome level, proteins that might exhibit phase behaviour and to design novel protein polymers consisting of biologically active peptide repeats that exhibit LCST or UCST transitions. These findings set the foundation for the prediction and encoding of phase behaviour at the sequence level.

  16. Phase separation of integral membrane proteins in Triton X-114 solution.

    PubMed

    Bordier, C

    1981-02-25

    A solution of the nonionic detergent Triton X-114 is homogeneous at 0 degrees C but separates in an aqueous phase and a detergent phase above 20 degrees C. The extent of this detergent phase separation increases with the temperature and is sensitive to the presence of other surfactants. The partition of proteins during phase separation in solutions of Triton X-114 is investigated. Hydrophilic proteins are found exclusively in the aqueous phase, and integral membrane proteins with an amphiphilic nature are recovered in the detergent phase. Triton X-114 is used to solubilize membranes and whole cells, and the soluble material is submitted to phase separation. Integral membrane proteins can thus be separated from hydrophilic proteins and identified as such in crude membrane or cellular detergent extracts.

  17. Apps of Steel: Are Exercise Apps Providing Consumers with Realistic Expectations?: A Content Analysis of Exercise Apps for Presence of Behavior Change Theory

    ERIC Educational Resources Information Center

    Cowan, Logan T.; Van Wagenen, Sarah A.; Brown, Brittany A.; Hedin, Riley J.; Seino-Stephan, Yukiko; Hall, P. Cougar; West, Joshua H.

    2013-01-01

    Objective. To quantify the presence of health behavior theory constructs in iPhone apps targeting physical activity. Methods. This study used a content analysis of 127 apps from Apple's (App Store) "Health & Fitness" category. Coders downloaded the apps and then used an established theory-based instrument to rate each app's inclusion of…

  18. Study of stationary phase metabolism via isotopomer analysis of amino acids from an isolated protein.

    PubMed

    Shaikh, Afshan S; Tang, Yinjie J; Mukhopadhyay, Aindrila; Martín, Héctor García; Gin, Jennifer; Benke, Peter I; Keasling, Jay D

    2010-01-01

    Microbial production of many commercially important secondary metabolites occurs during stationary phase, and methods to measure metabolic flux during this growth phase would be valuable. Metabolic flux analysis is often based on isotopomer information from proteinogenic amino acids. As such, flux analysis primarily reflects the metabolism pertinent to the growth phase during which most proteins are synthesized. To investigate central metabolism and amino acids synthesis activity during stationary phase, addition of fully (13)C-labeled glucose followed by induction of green fluorescent protein (GFP) expression during stationary phase was used. Our results indicate that Escherichia coli was able to produce new proteins (i.e., GFP) in the stationary phase, and the amino acids in GFP were mostly from degraded proteins synthesized during the exponential growth phase. Among amino acid biosynthetic pathways, only those for serine, alanine, glutamate/glutamine, and aspartate/asparagine had significant activity during the stationary phase.

  19. Study of Stationary Phase Metabolism Via Isotopomer Analysis of Amino Acids from an Isolated Protein

    SciTech Connect

    Shaikh, AfshanS.; Tang, YinjieJ.; Mukhopadhyay, Aindrila; Martin, Hector Garcia; Gin, Jennifer; Benke, Peter; Keasling, Jay D.

    2009-09-14

    Microbial production of many commercially important secondary metabolites occurs during stationary phase, and methods to measure metabolic flux during this growth phase would be valuable. Metabolic flux analysis is often based on isotopomer information from proteinogenic amino acids. As such, flux analysis primarily reflects the metabolism pertinent to the growth phase during which most proteins are synthesized. To investigate central metabolism and amino acids synthesis activity during stationary phase, addition of fully 13C-labeled glucose followed by induction of green fluorescent protein (GFP) expression during stationary phase was used. Our results indicate that Escherichia coli was able to produce new proteins (i.e., GFP) in the stationary phase, and the amino acids in GFP were mostly from degraded proteins synthesized during the exponential growth phase. Among amino acid biosynthetic pathways, only those for serine, alanine, glutamate/glutamine, and aspartate/asparagine had significant activity during the stationary phase.

  20. The Acute-Phase Proteins Serum Amyloid A and C Reactive Protein in Transudates and Exudates

    PubMed Central

    Okino, Alessandra M.; Bürger, Cristiani; Cardoso, Jefferson R.; Lavado, Edson L.; Lotufo, Paulo A.; Campa, Ana

    2006-01-01

    The distinction between exudates and transudates is very important in the patient management. Here we evaluate whether the acute-phase protein serum amyloid A (SAA), in comparison with C reactive protein (CRP) and total protein (TP), can be useful in this discrimination. CRP, SAA, and TP were determined in 36 exudate samples (27 pleural and 9 ascitic) and in 12 transudates (9 pleural and 3 ascitic). CRP, SAA, and TP were measured. SAA present in the exudate corresponded to 10% of the amount found in serum, that is, the exudate/serum ratio (E/S) was 0.10 ± 0.13. For comparison, the exudate/serum ratio for CRP and TP was 0.39 ± 0.37 and 0.68 ± 0.15, respectively. There was a strong positive correlation between serum and exudate SAA concentration (r = 0.764;p < 0.0001). The concentration of SAA in transudates was low and did not overlap with that found in exudates (0.02-0.21 versus 0.8–360.5 g/mL). SAA in pleural and ascitic exudates results mainly from leakage of the serum protein via the inflamed membrane. A comparison of the E/S ratio of SAA and CRP points SAA as a very good marker in discriminating between exudates and transudates. PMID:16864904

  1. LRAD3, a Novel LDL Receptor Family Member that Modulates Amyloid Precursor Protein Trafficking

    PubMed Central

    Ranganathan, Sripriya; Noyes, Nathaniel C.; Migliorini, Mary; Winkles, Jeffrey A.; Battey, Frances D.; Hyman, Bradley T.; Smith, Elizabeth; Yepes, Manuel; Mikhailenko, Irina; Strickland, Dudley K.

    2011-01-01

    We have identified a novel LDL receptor family member, termed LDL receptor class A domain containing 3 (LRAD3), which is expressed in neurons. The LRAD3 gene encodes an approximately 50 kDa type I transmembrane receptor with an ectodomain containing three LDLa repeats, a transmembrane domain and a cytoplasmic domain containing a conserved dileucine internalization motif and two polyproline motifs with potential to interact with WW domain containing proteins. Immunohistochemical analysis of mouse brain reveals LRAD3 expression in the cortex and hippocampus. In the mouse hippocampal derived cell line, HT22, LRAD3 partially co-localizes with amyloid precursor protein (APP), and interacts with APP as revealed by co-immunoprecipitation experiments. To identify the portion of APP that interacts with LRAD3, we employed solid phase binding assays which demonstrated that LRAD3 failed to bind to a soluble APP fragment (sAPPα) released following α-secretase cleavage. In contrast, C99, the β-secretase product that remains cell associated, co-precipitated with LRAD3, confirming that regions within this portion of APP are important for associating with LRAD3. The association of LRAD3 with APP increases the amyloidogenic pathway of APP processing, resulting in a decrease in sAPPα production and increased Aβ peptide production. Pulse-chase experiments confirm that LRAD3 expression significantly decreases the cellular half-live of mature APP. These results reveal that LRAD3 influences APP processing and raises the possibility that LRAD3 alters APP function in neurons including its downstream signaling. PMID:21795536

  2. Diabetes mHealth Apps: Designing for Greater Uptake.

    PubMed

    Brahmbhatt, Ronak; Niakan, Shadi; Saha, Nishita; Tewari, Anukriti; Pirani, Ashfiya; Keshavjee, Natasha; Mugambi, Dora; Alavi, Nasrin; Keshavjee, Karim

    2017-01-01

    mHealth apps are not being used. Over 45,000 mhealth apps are languishing in mobile app stores. We evaluated over 200 diabetes mobile apps found in the Apple and Google app stores using a framework that we recently published. None of the apps met all 15 criteria identified by our framework. The largest number of apps fell into the category of Type 1 diabetes blood sugar and medication trackers. Other types of apps included educational apps such as recipe apps, guideline dissemination apps, simple diabetes education apps, etc. There is a need for more Type 2 apps and for all types of apps that are better integrated into EMRs for more holistic care that can be prescribed by clinicians and monitored and supported by the health care team.

  3. An Android Communication App Forensic Taxonomy.

    PubMed

    Azfar, Abdullah; Choo, Kim-Kwang Raymond; Liu, Lin

    2016-09-01

    Due to the popularity of Android devices and applications (apps), Android forensics is one of the most studied topics within mobile forensics. Communication apps, such as instant messaging and Voice over IP (VoIP), are one popular app category used by mobile device users, including criminals. Therefore, a taxonomy outlining artifacts of forensic interest involving the use of Android communication apps will facilitate the timely collection and analysis of evidentiary materials from such apps. In this paper, 30 popular Android communication apps were examined, where a logical extraction of the Android phone images was collected using XRY, a widely used mobile forensic tool. Various information of forensic interest, such as contact lists and chronology of messages, was recovered. Based on the findings, a two-dimensional taxonomy of the forensic artifacts of the communication apps is proposed, with the app categories in one dimension and the classes of artifacts in the other dimension. Finally, the artifacts identified in the study of the 30 communication apps are summarized using the taxonomy. It is expected that the proposed taxonomy and the forensic findings in this paper will assist forensic investigations involving Android communication apps.

  4. Fibrinogen-like protein 1, a hepatocyte derived protein is an acute phase reactant

    SciTech Connect

    Liu Zhilin; Ukomadu, Chinweike

    2008-01-25

    Fibrinogen-like protein 1 (FGL1) is a hepatocyte derived protein that is upregulated in regenerating rodent livers following partial hepatectomy. It has been implicated as a mitogen for liver cell proliferation. In this study, we show that recombinant human IL-6 induces FGL1 expression in Hep G2 cells in a pattern similar to those of acute phase reactants. Following induction of acute inflammation in rats by subcutaneous injection of turpentine oil, serum FGL1 levels are also enhanced. Although, a recent report suggests that FGL1 associates almost exclusively with the fibrin matrix, we report here that approximately 20% of the total plasma FGL1 remains free. The enhancement of FGL1 levels in vitro by IL-6 and its induction after turpentine oil injection suggest that it is an acute phase reactant. Its presence in bound and free forms in the blood also implies biological roles that extend beyond the proposed autocrine effect it has on hepatocytes during regeneration.

  5. Both pre- and post-synaptic alterations contribute to aberrant cholinergic transmission in superior cervical ganglia of APP(-/-) mice.

    PubMed

    Cai, Zhao-Lin; Zhang, Jia-Jia; Chen, Ming; Wang, Jin-Zhao; Xiao, Peng; Yang, Li; Long, Cheng

    2016-11-01

    Though amyloid precursor protein (APP) can potentially be cleaved to generate the pathological amyloid β peptide (Aβ), APP itself plays an important role in regulating neuronal activity. APP deficiency causes functional impairment in cholinergic synaptic transmission and cognitive performance. However, the mechanisms underlying altered cholinergic synaptic transmission in APP knock-out mice (APP(-/-)) are poorly understood. In this study, we conducted in vivo extracellular recording to investigate cholinergic compound action potentials (CAPs) of the superior cervical ganglion (SCG) in APP(-/-) and littermate wild-type (WT) mice. Our results demonstrate that APP not only regulates presynaptic activity, but also affects postsynaptic function at cholinergic synapses in SCG. APP deficiency reduces the number of vesicles in presynaptic terminalsand attenuatesthe amplitude of CAPs, likely due to dysfunction of high-affinity choline transporters. Pharmacological and biochemical examination showed that postsynaptic responsesmediated by α4β2 and α7 nicotinic acetylcholine receptors are reduced in the absence of APP. Our research provides evidences on how APP regulates cholinergic function and therefore may help to identify potential therapeutic targets to treat cholinergic dysfunction associated with Alzheimer's disease pathogenesis.

  6. Changes in the levels of some acute-phase proteins in human immunodeficiency virus-1 infected patients, following interleukin-2 treatment

    PubMed Central

    Barbai, V H; Ujhelyi, E; Szlávik, J; Vietorisz, I; Varga, L; Fey, E; Füst, G; Bánhegyi, D

    2010-01-01

    Intermittent interleukin (IL)-2 administration to human immunodeficiency virus (HIV)-1 infected patients is well documented and generally used, but there is limited information about the changes of acute-phase protein (APP) levels in response to this treatment. Fifteen patients undergoing highly active anti-retroviral therapy (HAART) treatment, with undetectable viral load, but low CD4+ cell count (<300/µl), have been treated with 3·6 M IU Proleukine® administered twice daily by subcutaneous injection over 5 days. C-reactive protein (CRP), d-dimer, C3, C9, C1-inh and alpha-2HS glycoprotein levels were measured immediately before IL-2 administration, as well as on day 5 and 2–3 weeks thereafter. After IL-2 administration, both mean d-dimer and CRP levels increased significantly (P < 0·001), but returned (P < 0·001) to baseline within the subsequent 2–3 weeks. Alpha-2HS glycoprotein decreased immediately after IL-2 administration. No significant differences were detected in the levels of C3, C9 and C1-inh. A significant, positive correlation (r = 0·5178, P = 0·0008) was ascertained between the changes of CRP level, measured immediately before as well as 5 days after IL-2 administration, and changes in CD4 T cell counts measured 2–3 weeks before and after treatment, respectively. IL-2 administration induces rapid elevation of two major APPs (CRP, d-dimer). The positive correlation observed between the changes of CRP levels and CD4+ cell counts after IL-2 administration may indicate that the abrupt, but transitory overproduction of CRP might contribute to the CD4+ cell count-increasing effect of the drug and/ or may be associated with serious side effects. PMID:20408859

  7. The E2 Domains of APP and APLP1 Share a Conserved Mode of Dimerization

    SciTech Connect

    S Lee; Y Xue; J Hulbert; Y Wang; X Liu; B Demeler; Y Ha

    2011-12-31

    Amyloid precursor protein (APP) is genetically linked to Alzheimer's disease. APP is a type I membrane protein, and its oligomeric structure is potentially important because this property may play a role in its function or affect the processing of the precursor by the secretases to generate amyloid {beta}-peptide. Several independent studies have shown that APP can form dimers in the cell, but how it dimerizes remains controversial. At least three regions of the precursor, including a centrally located and conserved domain called E2, have been proposed to contribute to dimerization. Here we report two new crystal structures of E2, one from APP and the other from APLP1, a mammalian APP homologue. Comparison with an earlier APP structure, which was determined in a different space group, shows that the E2 domains share a conserved and antiparallel mode of dimerization. Biophysical measurements in solution show that heparin binding induces E2 dimerization. The 2.1 {angstrom} resolution electron density map also reveals phosphate ions that are bound to the protein surface. Mutational analysis shows that protein residues interacting with the phosphate ions are also involved in heparin binding. The locations of two of these residues, Arg-369 and His-433, at the dimeric interface suggest a mechanism for heparin-induced protein dimerization.

  8. Call for Increased Patient Support Focus: Review and Evaluation of Mobile Apps for Tuberculosis Prevention and Treatment.

    PubMed

    Iribarren, Sarah; Schnall, Rebecca

    2016-01-01

    Tuberculosis (TB) remains a major global public health problem and is a leading killer due to an infectious disease. Mobile applications (apps) could support TB prevention and treatment. App stores were searched and of the 1332 reviewed 24 met our inclusion criteria. For each app 11 functionalities were assessed. The majority were targeted towards clinicians (n=17), few patient focused (n=4). Most had fewer than 4 functions out of 11, inform and record being the highest. Peer reviewed publications were identified for 2 of the apps and 3 apps in testing stage were found in the grey literature. Apps for TB prevention and treatment had minimal functionality, primarily targeted clinicians, and focused on information or data collection. None were for patient self-management of care and treatment or to improve patient-provider interactions. Identifying TB patient needs and involving them in the design phase is recommended.

  9. APP Regulates Microglial Phenotype in a Mouse Model of Alzheimer's Disease

    PubMed Central

    Manocha, Gunjan D.; Floden, Angela M.; Rausch, Keiko; Kulas, Joshua A.; McGregor, Brett A.; Rojanathammanee, Lalida; Puig, Kelley R.; Puig, Kendra L.; Karki, Sanjib; Nichols, Michael R.; Darland, Diane C.; Porter, James E.

    2016-01-01

    Prior work suggests that amyloid precursor protein (APP) can function as a proinflammatory receptor on immune cells, such as monocytes and microglia. Therefore, we hypothesized that APP serves this function in microglia during Alzheimer's disease. Although fibrillar amyloid β (Aβ)-stimulated cytokine secretion from both wild-type and APP knock-out (mAPP−/−) microglial cultures, oligomeric Aβ was unable to stimulate increased secretion from mAPP−/− cells. This was consistent with an ability of oligomeric Aβ to bind APP. Similarly, intracerebroventricular infusions of oligomeric Aβ produced less microgliosis in mAPP−/− mice compared with wild-type mice. The mAPP−/− mice crossed to an APP/PS1 transgenic mouse line demonstrated reduced microgliosis and cytokine levels and improved memory compared with wild-type mice despite robust fibrillar Aβ plaque deposition. These data define a novel function for microglial APP in regulating their ability to acquire a proinflammatory phenotype during disease. SIGNIFICANCE STATEMENT A hallmark of Alzheimer's disease (AD) brains is the accumulation of amyloid β (Aβ) peptide within plaques robustly invested with reactive microglia. This supports the notion that Aβ stimulation of microglial activation is one source of brain inflammatory changes during disease. Aβ is a cleavage product of the ubiquitously expressed amyloid precursor protein (APP) and is able to self-associate into a wide variety of differently sized and structurally distinct multimers. In this study, we demonstrate both in vitro and in vivo that nonfibrillar, oligomeric forms of Aβ are able to interact with the parent APP protein to stimulate microglial activation. This provides a mechanism by which metabolism of APP results in possible autocrine or paracrine Aβ production to drive the microgliosis associated with AD brains. PMID:27511018

  10. Interaction of Tau with Fe65 links tau to APP.

    PubMed

    Barbato, Christian; Canu, Nadia; Zambrano, Nicola; Serafino, Annalucia; Minopoli, Giuseppina; Ciotti, Maria Teresa; Amadoro, Giuseppina; Russo, Tommaso; Calissano, Pietro

    2005-03-01

    The beta-amyloid precursor protein APP and the microtubule-associated protein Tau play a crucial role in the pathogenesis of Alzheimer's disease (AD). However, the possible molecular events linking these two proteins are still unknown. Here, we show that Fe65, one of the ligands of the APP cytodomain, is associated with Tau in vivo and in vitro, as demonstrated by co-immunoprecipitation, co-localization, and FRET experiments. Deletion studies indicated that the N-terminal domain of Tau and the PTB1 domain of Fe65 are required for this association. This interaction is regulated by the phosphorylation of Tau at selected sites, by glycogen synthase kinase-3beta (GSK3beta) and cyclin-dependent kinase 5 (Cdk5), and requires an intact microtubule network. Furthermore, laser scanner microscopy and co-immunoprecipitation experiments provide preliminary evidence of possible complex(es) involving Tau, Fe65, APP. These findings open new perspectives for the study of the possible crosstalk between these proteins in the pathogenesis of AD.

  11. Parametric sensitivity analysis of avian pancreatic polypeptide (APP).

    PubMed

    Zhang, H; Wong, C F; Thacher, T; Rabitz, H

    1995-10-01

    Computer simulations utilizing a classical force field have been widely used to study biomolecular properties. It is important to identify the key force field parameters or structural groups controlling the molecular properties. In the present paper the sensitivity analysis method is applied to study how various partial charges and solvation parameters affect the equilibrium structure and free energy of avian pancreatic polypeptide (APP). The general shape of APP is characterized by its three principal moments of inertia. A molecular dynamics simulation of APP was carried out with the OPLS/Amber force field and a continuum model of solvation energy. The analysis pinpoints the parameters which have the largest (or smallest) impact on the protein equilibrium structure (i.e., the moments of inertia) or free energy. A display of the protein with its atoms colored according to their sensitivities illustrates the patterns of the interactions responsible for the protein stability. The results suggest that the electrostatic interactions play a more dominant role in protein stability than the part of the solvation effect modeled by the atomic solvation parameters.

  12. Sorting of streptavidin protein coats on phase-separating model membranes.

    PubMed

    Manley, Suliana; Horton, Margaret R; Lecszynski, Szymon; Gast, Alice P

    2008-09-01

    Heterogeneities in cell membranes due to the ordering of lipids and proteins are thought to play an important role in enabling protein and lipid trafficking throughout the secretory pathway and in maintaining cell polarization. Protein-coated vesicles provide a major mechanism for intracellular transport of select cargo, which may be sorted into lipid microdomains; however, the mechanisms and physical constraints for lipid sorting by protein coats are relatively unexplored. We studied the influence of membrane-tethered protein coats on the sorting, morphology, and phase behavior of liquid-ordered lipid domains in a model system of giant unilamellar vesicles composed of dioleoylphosphatidylcholine, sphingomyelin, and cholesterol. We created protein-coated membranes by forming giant unilamellar vesicles containing a small amount of biotinylated lipid, thereby creating binding sites for streptavidin and avidin proteins in solution. We found that individual tethered proteins colocalize with the liquid-disordered phase, whereas ordered protein domains on the membrane surface colocalize with the liquid-ordered phase. These observations may be explained by considering the thermodynamics of this coupled system, which maximizes its entropy by cosegregating ordered protein and lipid domains. In addition, protein ordering inhibits lipid domain rearrangement and modifies the morphology and miscibility transition temperature of the membrane, most dramatically near the critical point in the membrane phase diagram. This observation suggests that liquid-ordered domains are stabilized by contact with ordered protein domains; it also hints at an approach to the stabilization of lipid microdomains by cross-linked protein clusters or ordered protein coats.

  13. The course of acute-phase proteins and serum cortisol in mastitis metritis agalactia (MMA) of the sow and sow performance.

    PubMed

    van Gelder, K N; Bilkei, G

    2005-01-15

    The objective of this study was to evaluate changes in acute-phase proteins (APPs) during mastitis metritis agalactia (MMA) in sows. Sows with MMA (group one, n=15) and healthy sows (group two, n = 15) were evaluated at days 0, 5, 10, 15, and 20 postpartum. Number of total born, liveborn, stillborn, and mummified pigs did not differ significantly between the groups. Preweaning mortality was higher (P < 0.001) among MMA sows than among healthy control animals. The offspring of healthy sows had higher (P < 0.05) weaning litter weights than the off-spring of MMA sows. Mean serum alpha 1-acid glycoprotein (AGP) concentrations were higher in MMA sows on the days 1 (P < 0.05), 5 (P = 0.05), and 10 (P < 0.001) post partum. Mean serum haptoglobin (HPT) was higher in MMA sows on days 1, 5 (P < 0.001), and 10 (P < 0.05) of lactation. Cortisol serum concentrations up to day 10 post partum were higher (P < 0.001) in MMA sows than in healthy sows. AGP was negatively correlated with litter weight, indicating that activation of the cellular immune response in sows negatively affects the growth rate of suckling piglets. Correlations were found between the overall means for weight, acute-phase proteins, and serum cortisol concentration.

  14. The Ames dwarf mutation attenuates Alzheimer's disease phenotype of APP/PS1 mice.

    PubMed

    Puig, Kendra L; Kulas, Joshua A; Franklin, Whitney; Rakoczy, Sharlene G; Taglialatela, Giulio; Brown-Borg, Holly M; Combs, Colin K

    2016-04-01

    APP/PS1 double transgenic mice expressing human mutant amyloid precursor protein (APP) and presenilin-1 (PS1) demonstrate robust brain amyloid beta (Aβ) peptide containing plaque deposition, increased markers of oxidative stress, behavioral dysfunction, and proinflammatory gliosis. On the other hand, lack of growth hormone, prolactin, and thyroid-stimulating hormone due to a recessive mutation in the Prop 1 gene (Prop1df) in Ames dwarf mice results in a phenotype characterized by potentiated antioxidant mechanisms, improved learning and memory, and significantly increased longevity in homozygous mice. Based on this, we hypothesized that a similar hormone deficiency might attenuate disease changes in the brains of APP/PS1 mice. To test this idea, APP/PS1 mice were crossed to the Ames dwarf mouse line. APP/PS1, wild-type, df/+, df/df, df/+/APP/PS1, and df/df/APP/PS1 mice were compared at 6 months of age through behavioral testing and assessing amyloid burden, reactive gliosis, and brain cytokine levels. df/df mice demonstrated lower brain growth hormone and insulin-like growth factor 1 concentrations. This correlated with decreased astrogliosis and microgliosis in the df/df/APP/PS1 mice and, surprisingly, reduced Aβ plaque deposition and Aβ 1-40 and Aβ 1-42 concentrations. The df/df/APP/PS1 mice also demonstrated significantly elevated brain levels of multiple cytokines in spite of the attenuated gliosis. These data indicate that the df/df/APP/PS1 line is a unique resource in which to study aging and resistance to disease and suggest that the affected pituitary hormones may have a role in regulating disease progression.

  15. Time-Dependent Increase of Chitinase1 in APP/PS1 Double Transgenic Mice.

    PubMed

    Xiao, Qian; Shi, Rui; Yang, Wenxiu; Zou, Yan; Du, Yinshi; Zhang, Man; Yu, Weihua; Lü, Yang

    2016-07-01

    It is reported that chitinase1 increases in Alzheimer's disease (AD). However, the alteration of chitinase1 in the progress of AD is still unclear. Thus, we designed the present study to detect chitinase1 level in different stages of APP/PS1 double transgenic mice. Experimental models were APP/PS1 double transgenic mice with 4, 12 and 22 months. Cognitive function was detected by Morris water maze test in APP/PS1 mice as well as controls. ELISA and the quantitative RT-PCR were used to detect chitinase1 level in different groups. The study displayed that expression of chitinase1 gradually increased in a time-dependent manner in APP/PS1 mice, while there were no statistical differences among the wild-type mice in varies ages. Moreover, chitnase1 increased significantly in APP/PS1 mice aged 12 and 22 months compared with the age matched wild-type group, respectively. However, no difference of chitnase1 was found between 4 months-old APP/PS1 mice and wild-type mice. Comparing with the age matched wild type group, the consequences of mRNA on the increase in chitnase1 is in accordance with protein in APP/PS1 mice. Furthermore, Morris water maze showed that 4 months-old APP/PS1 mice have normal spatial learning and impaired spatial memory; both spatial learning and spatial memory in 12 and 22 months-old APP/PS1 mice were declined. Time-dependent increase of chitnase1 in APP/PS1 double transgenic mice indicates that the level of chitinase1 is associated with decline of cognition. Therefore, chitinase1 might be a biomarker of disease progression in AD.

  16. Platelet APP isoform ratios in asymptomatic young adults expressing an AD-related presenilin-1 mutation.

    PubMed

    Baskin, F; Rosenberg, R N; Iyer, L; Schellenberg, G D; Hynan, L; Nee, L E

    2001-01-15

    The Alzheimer's disease (AD) related amyloid precursor protein (APP) is stored, cleaved and released similarly from neurons and from platelets. We have reported that the proportion of 120-130 to 110 kDa carboxyl-cleaved APP present in the platelets of AD patients is significantly lower than that of platelets of age-matched controls. This reduced APP isoform ratio, not seen in several other disease groups, is further reduced as the severity of AD increases. Since the neuropathology of AD is believed to begin many years before the onset of cognitive loss, we have also compared platelet APP ratios of four pre-symptomatic young adults carrying a presenilin-1 mutation to seven siblings homozygous for the normal PS-1 gene in an effort to determine whether reduced APP ratios are present before apparent cognitive loss in familial AD. Decreased platelet APP ratios were not seen in any of these subjects at this time. We will continue to monitor these subjects as they near the mean age of AD onset in these families. As the magnitude of the APP ratio reduction is proportional to the severity of cognitive loss in sporadic AD, these cognitively normal incipient AD subjects would not be expected to present significant reductions in this AD severity index at this time. Alternatively, the absence of platelet APP ratio reductions may result from a failure of platelets from familial PS-1 AD subjects to manifest altered APPs, as has been reported for PS-2 AD subjects, unlike those of sporadic AD patients. Continued monitoring of cognitive status in our sub-set of controls with AD-like low APP ratios may yet validate the ability of this assay to detect incipient sporadic AD.

  17. Hypnosis--there's an app for that: a systematic review of hypnosis apps.

    PubMed

    Sucala, Madalina; Schnur, Julie B; Glazier, Kimberly; Miller, Sarah J; Green, Joseph P; Montgomery, Guy H

    2013-01-01

    This study systematically reviews the hypnosis apps available via iTunes that were compatible with iPhone or iPad. Of 1455 apps identified on iTunes, 407 met inclusion criteria and were further reviewed. Most common hypnosis app targets were weight loss (23%), boosting self-esteem (20%), and relaxation/stress reduction (19%); 83% of apps delivered hypnosis via audio track, and 37% allowed tailoring. Less than 14% of apps reported disclaimers. None of the apps reported having been tested for efficacy, and none reported being evidence based. Although apps have the potential to enhance hypnosis delivery, it seems as though technology has raced ahead of the supporting science. Recommendations from clinical researchers and policy makers are needed to inform responsible hypnosis app development and use.

  18. Proteomic analysis of Clostridium thermocellum core metabolism: relative protein expression profiles and growth phase-dependent changes in protein expression

    PubMed Central

    2012-01-01

    Background Clostridium thermocellum produces H2 and ethanol, as well as CO2, acetate, formate, and lactate, directly from cellulosic biomass. It is therefore an attractive model for biofuel production via consolidated bioprocessing. Optimization of end-product yields and titres is crucial for making biofuel production economically feasible. Relative protein expression profiles may provide targets for metabolic engineering, while understanding changes in protein expression and metabolism in response to carbon limitation, pH, and growth phase may aid in reactor optimization. We performed shotgun 2D-HPLC-MS/MS on closed-batch cellobiose-grown exponential phase C. thermocellum cell-free extracts to determine relative protein expression profiles of core metabolic proteins involved carbohydrate utilization, energy conservation, and end-product synthesis. iTRAQ (isobaric tag for relative and absolute quantitation) based protein quantitation was used to determine changes in core metabolic proteins in response to growth phase. Results Relative abundance profiles revealed differential levels of putative enzymes capable of catalyzing parallel pathways. The majority of proteins involved in pyruvate catabolism and end-product synthesis were detected with high abundance, with the exception of aldehyde dehydrogenase, ferredoxin-dependent Ech-type [NiFe]-hydrogenase, and RNF-type NADH:ferredoxin oxidoreductase. Using 4-plex 2D-HPLC-MS/MS, 24% of the 144 core metabolism proteins detected demonstrated moderate changes in expression during transition from exponential to stationary phase. Notably, proteins involved in pyruvate synthesis decreased in stationary phase, whereas proteins involved in glycogen metabolism, pyruvate catabolism, and end-product synthesis increased in stationary phase. Several proteins that may directly dictate end-product synthesis patterns, including pyruvate:ferredoxin oxidoreductases, alcohol dehydrogenases, and a putative bifurcating hydrogenase

  19. Role of Drosophila Amyloid Precursor Protein in Memory Formation

    PubMed Central

    Preat, Thomas; Goguel, Valérie

    2016-01-01

    The amyloid precursor protein (APP) is a membrane protein engaged in complex proteolytic pathways. APP and its derivatives have been shown to play a central role in Alzheimer’s disease (AD), a progressive neurodegenerative disease characterized by memory decline. Despite a huge effort from the research community, the primary cause of AD remains unclear, making it crucial to better understand the physiological role of the APP pathway in brain plasticity and memory. Drosophila melanogaster is a model system well-suited to address this issue. Although relatively simple, the fly brain is highly organized, sustains several forms of learning and memory, and drives numerous complex behaviors. Importantly, molecules and mechanisms underlying memory processes are conserved from flies to mammals. The fly encodes a single non-essential APP homolog named APP-Like (APPL). Using in vivo inducible RNA interference strategies, it was shown that APPL knockdown in the mushroom bodies (MB)—the central integrative brain structure for olfactory memory—results in loss of memory. Several APPL derivatives, such as secreted and full-length membrane APPL, may play different roles in distinct types of memory phases. Furthermore, overexpression of Drosophila amyloid peptide exacerbates the memory deficit caused by APPL knockdown, thus potentiating memory decline. Data obtained in the fly support the hypothesis that APP acts as a transmembrane receptor, and that disruption of its normal function may contribute to cognitive impairment during early AD. PMID:28008309

  20. Redefining Cheminformatics with Intuitive Collaborative Mobile Apps

    PubMed Central

    Clark, Alex M; Ekins, Sean; Williams, Antony J

    2012-01-01

    Abstract The proliferation of mobile devices such as smartphones and tablet computers has recently been extended to include a growing ecosystem of increasingly sophisticated chemistry software packages, commonly known as apps. The capabilities that these apps can offer to the practicing chemist are approaching those of conventional desktop-based software, but apps tend to be focused on a relatively small range of tasks. To overcome this, chemistry apps must be able to seamlessly transfer data to other apps, and through the network to other devices, as well as to other platforms, such as desktops and servers, using documented file formats and protocols whenever possible. This article describes the development and state of the art with regard to chemistry-aware apps that make use of facile data interchange, and some of the scenarios in which these apps can be inserted into a chemical information workflow to increase productivity. A selection of contemporary apps is used to demonstrate their relevance to pharmaceutical research. Mobile apps represent a novel approach for delivery of cheminformatics tools to chemists and other scientists, and indications suggest that mobile devices represent a disruptive technology for drug discovery, as they have been to many other industries. PMID:23198002

  1. Color Addition and Subtraction Apps

    NASA Astrophysics Data System (ADS)

    Ruiz, Frances; Ruiz, Michael J.

    2015-10-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step in understanding mathematical representations of RGB color. Finally, color addition and subtraction are presented for the X11 colors from web design to illustrate yet another real-life application of color mixing.

  2. Liquid-Liquid Phase Separation in a Dual Variable Domain Immunoglobulin Protein Solution: Effect of Formulation Factors and Protein-Protein Interactions.

    PubMed

    Raut, Ashlesha S; Kalonia, Devendra S

    2015-09-08

    Dual variable domain immunoglobulin proteins (DVD-Ig proteins) are large molecules (MW ∼ 200 kDa) with increased asymmetry because of their extended Y-like shape, which results in increased formulation challenges. Liquid-liquid phase separation (LLPS) of protein solutions into protein-rich and protein-poor phases reduces solution stability at intermediate concentrations and lower temperatures, and is a serious concern in formulation development as therapeutic proteins are generally stored at refrigerated conditions. In the current work, LLPS was studied for a DVD-Ig protein molecule as a function of solution conditions by measuring solution opalescence. LLPS of the protein was confirmed by equilibrium studies and by visually observing under microscope. The protein does not undergo any structural change after phase separation. Protein-protein interactions were measured by light scattering (kD) and Tcloud (temperature that marks the onset of phase separation). There is a good agreement between kD measured in dilute solution with Tcloud measured in the critical concentration range. Results indicate that the increased complexity of the molecule (with respect to size, shape, and charge distribution on the molecule) increases contribution of specific and nonspecific interactions in solution, which are affected by formulation factors, resulting in LLPS for DVD-Ig protein.

  3. Ab initio protein phasing at 1.4 A resolution: the new phasing approach of SIR2003-N.

    PubMed

    Burla, Maria C; Carrozzini, Benedetta; Caliandro, Rocco; Cascarano, Giovanni L; De Caro, Liberato; Giacovazzo, Carmelo; Polidori, Giampiero

    2003-11-01

    New algorithms for solving ab initio protein crystal structures have been identified and implemented in a modified version of the program SIR2002. They succeed in solving numerous protein structures diffracting at atomic resolution; the solution was also attained when data were cut at 1.4 A resolution. The direct-space refinement procedure of SIR2003-N takes advantage of using the envelope of the protein, calculated during the phasing process from the current phases. The electron-density map is modified by assuming different weights for pixels within the envelope or out of it, so tentatively depleting the intensities of the false peaks. The map is then inverted and the resulting phase sets may improve their values. The new phasing strategy is also based on an optimal use of some figures of merit, one of which may be successfully applied in the early stages of the phasing process: only the most promising trials are submitted to the complete phasing procedure, so saving computing time. SIR2003-N has been successfully applied also in solving some protein structures diffracting at 1.4-1.5 A resolution.

  4. Epic Allies: Development of a Gaming App to Improve Antiretroviral Therapy Adherence Among Young HIV-Positive Men Who Have Sex With Men

    PubMed Central

    Muessig, Kathryn Elizabeth; McNulty, Tobias; Soni, Karina; Knudtson, Kelly; Lemann, Alex; Nwoko, Nkechinyere; Hightow-Weidman, Lisa B

    2016-01-01

    Background In the United States, the human immunodeficiency virus (HIV) disproportionately affects young men who have sex with men (YMSM). For HIV-positive individuals, adherence to antiretroviral therapy (ART) is critical for achieving optimal health outcomes and reducing secondary transmission of HIV. However, YMSM often struggle with ART adherence. Novel mobile phone apps that incorporate game-based mechanics and social networking elements represent a promising intervention approach for improving ART adherence among YMSM. Objective This study used a multiphase, iterative development process to create an ART adherence app for YMSM. Methods The three-phase development process included: (1) theory-based concept development jointly by public health researchers and the technology team, (2) assessment of the target population’s ART adherence needs and app preferences and development and testing of a clickable app prototype, and (3) development and usability testing of the final app prototype. Results The initial theory-based app concept developed in Phase One included medication reminders, daily ART adherence tracking and visualization, ART educational modules, limited virtual interactions with other app users, and gamification elements. In Phase Two, adherence needs, including those related to information, motivation, and behavioral skills, were identified. Participants expressed preferences for an ART adherence app that was informational, interactive, social, and customizable. Based on the findings from Phase Two, additional gaming features were added in Phase Three, including an interactive battle, superhero app theme, and app storyline. Other features were modified to increase interactivity and customization options and integrate the game theme. During usability testing of the final prototype, participants were able to understand and navigate the app successfully and rated the app favorably. Conclusions An iterative development process was critical for the

  5. A Guide to Help Consumers Choose Apps and Avoid App Overload

    ERIC Educational Resources Information Center

    Schuster, Ellen; Zimmerman, Lynda

    2014-01-01

    Mobile technology has transformed the way consumers access and use information. The exponential growth of mobile apps makes finding suitable, easy-to-use nutrition and health-related apps challenging. A guide for consumers helps them ask important questions before downloading apps. The guide can be adapted for other Extension disciplines.

  6. Solubilization of proteins in aqueous two-phase extraction through combinations of phase-formers and displacement agents.

    PubMed

    Kress, Christian; Sadowski, Gabriele; Brandenbusch, Christoph

    2017-03-01

    The aqueous two-phase extraction (ATPE) of therapeutic proteins is a promising separation alternative to cost-intensive chromatography, still being the workhorse of nowadays downstream processing. As shown in many publications, using NaCl as displacement agent in salt-polymer ATPE allows for a selective purification of the target protein immunoglobulin G (IgG) from human serum albumin (HSA, represents the impurity). However a high yield of the target protein is only achievable as long as the protein is stabilized in solution and not precipitated. In this work the combined influence of NaCl and polyethylene glycol (Mw=2000g/mol) on the IgG-IgG interactions was determined using composition gradient multi-angle light scattering (CG-MALS) demonstrating that NaCl induces a solubilization of IgG in polyethylene glycol 2000 solution. Moreover it is shown that the displacement agent NaCl has a significant and beneficial influence on the IgG solubility in polyethyleneglycol2000-citrate aqueous two-phase system (ATPS) which can also be accessed by these advanced B22 measurements. By simultaneous consideration of IgG solubility data with results of the ATPS phase behavior (especially volume fraction of the respective phases) allows for the selection of process tailored ATPS including identification of the maximum protein feed concentration. Through this approach an ATPS optimization is accessible providing high yields and selectivity of the target protein (IgG).

  7. Determination of protein loss during aqueous and phase partition fixation using formalin and glutaraldehyde

    SciTech Connect

    Mays, E.T.; Feldhoff, R.C.; Nettleton, G.S.

    1984-10-01

    In phase partition fixation tissue is immersed in an organic solvent at equilibrium with an aqueous phase containing a fixing agent. By using radioisotope labeling techniques the effects of phase partition fixation on protein retention during fixation of tissue with formalin and glutaraldehyde have been determined and compared with those of standard aqueous fixation using these fixatives. It has been shown that retention of protein in tissue during phase partition fixation was as good or better than during aqueous fixation. Improved retention provides further evidence that phase partition fixation may be a useful alternative to aqueous fixation.

  8. Distinct patterns of APP processing in the CNS in autosomal-dominant and sporadic Alzheimer disease.

    PubMed

    Pera, Marta; Alcolea, Daniel; Sánchez-Valle, Raquel; Guardia-Laguarta, Cristina; Colom-Cadena, Martí; Badiola, Nahuai; Suárez-Calvet, Marc; Lladó, Albert; Barrera-Ocampo, Alvaro A; Sepulveda-Falla, Diego; Blesa, Rafael; Molinuevo, José L; Clarimón, Jordi; Ferrer, Isidre; Gelpi, Ellen; Lleó, Alberto

    2013-02-01

    Autosomal-dominant Alzheimer disease (ADAD) is a genetic disorder caused by mutations in Amyloid Precursor Protein (APP) or Presenilin (PSEN) genes. Studies from families with ADAD have been critical to support the amyloid cascade hypothesis of Alzheimer disease (AD), the basis for the current development of amyloid-based disease-modifying therapies in sporadic AD (SAD). However, whether the pathological changes in APP processing in the CNS in ADAD are similar to those observed in SAD remains unclear. In this study, we measured β-site APP-cleaving enzyme (BACE) protein levels and activity, APP and APP C-terminal fragments in brain samples from subjects with ADAD carrying APP or PSEN1 mutations (n = 18), patients with SAD (n = 27) and age-matched controls (n = 22). We also measured sAPPβ and BACE protein levels, as well as BACE activity, in CSF from individuals carrying PSEN1 mutations (10 mutation carriers and 7 non-carrier controls), patients with SAD (n = 32) and age-matched controls (n = 11). We found that in the brain, the pattern in ADAD was characterized by an increase in APP β-C-terminal fragment (β-CTF) levels despite no changes in BACE protein levels or activity. In contrast, the pattern in SAD in the brain was mainly characterized by an increase in BACE levels and activity, with less APP β-CTF accumulation than ADAD. In the CSF, no differences were found between groups in BACE activity or expression or sAPPβ levels. Taken together, these data suggest that the physiopathological events underlying the chronic Aβ production/clearance imbalance in SAD and ADAD are different. These differences should be considered in the design of intervention trials in AD.

  9. Keratinocytes from APP/APLP2-deficient mice are impaired in proliferation, adhesion and migration in vitro.

    PubMed

    Siemes, Christina; Quast, Thomas; Kummer, Christiane; Wehner, Sven; Kirfel, Gregor; Müller, Ulrike; Herzog, Volker

    2006-07-01

    Growing evidence shows that the soluble N-terminal form (sAPPalpha) of the amyloid precursor protein (APP) represents an epidermal growth factor fostering keratinocyte proliferation, migration and adhesion. APP is a member of a protein family including the two mammalian amyloid precursor-like proteins APLP1 and APLP2. In the mammalian epidermis, only APP and APLP2 are expressed. APP and APLP2-deficient mice die shortly after birth but do not display a specific epidermal phenotype. In this report, we investigated the epidermis of APP and/or APLP2 knockout mice. Basal keratinocytes showed reduced proliferation in vivo by about 40%. Likewise, isolated keratinocytes exhibited reduced proliferation rates in vitro, which could be completely rescued by either exogenously added recombinant sAPPalpha, or by co-culture with dermal fibroblasts derived from APP knockout mice. Moreover, APP-knockout keratinocytes revealed reduced migration velocity resulting from severely compromised cell substrate adhesion. Keratinocytes from double knockout mice died within the first week of culture, indicating essential functions of APP-family members for survival in vitro. Our data indicate that sAPPalpha has to be considered as an essential epidermal growth factor which, however, in vivo can be functionally compensated to a certain extent by other growth factors, e.g., factors released from dermal fibroblasts.

  10. Expert Involvement Predicts mHealth App Downloads: Multivariate Regression Analysis of Urology Apps

    PubMed Central

    Osório, Luís; Cavadas, Vitor; Fraga, Avelino; Carrasquinho, Eduardo; Cardoso de Oliveira, Eduardo; Castelo-Branco, Miguel; Roobol, Monique J

    2016-01-01

    Background Urological mobile medical (mHealth) apps are gaining popularity with both clinicians and patients. mHealth is a rapidly evolving and heterogeneous field, with some urology apps being downloaded over 10,000 times and others not at all. The factors that contribute to medical app downloads have yet to be identified, including the hypothetical influence of expert involvement in app development. Objective The objective of our study was to identify predictors of the number of urology app downloads. Methods We reviewed urology apps available in the Google Play Store and collected publicly available data. Multivariate ordinal logistic regression evaluated the effect of publicly available app variables on the number of apps being downloaded. Results Of 129 urology apps eligible for study, only 2 (1.6%) had >10,000 downloads, with half having ≤100 downloads and 4 (3.1%) having none at all. Apps developed with expert urologist involvement (P=.003), optional in-app purchases (P=.01), higher user rating (P<.001), and more user reviews (P<.001) were more likely to be installed. App cost was inversely related to the number of downloads (P<.001). Only data from the Google Play Store and the developers’ websites, but not other platforms, were publicly available for analysis, and the level and nature of expert involvement was not documented. Conclusions The explicit participation of urologists in app development is likely to enhance its chances to have a higher number of downloads. This finding should help in the design of better apps and further promote urologist involvement in mHealth. Official certification processes are required to ensure app quality and user safety. PMID:27421338

  11. Experimental phasing for structure determination using membrane-protein crystals grown by the lipid cubic phase method

    SciTech Connect

    Li, Dianfan; Pye, Valerie E.; Caffrey, Martin

    2015-01-01

    Very little information is available in the literature concerning the experimental heavy-atom phasing of membrane-protein structures where the crystals have been grown using the lipid cubic phase (in meso) method. In this paper, pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine labelling as applied to an integral membrane kinase crystallized in meso are described. An assay to assess cysteine accessibility for mercury labelling of membrane proteins is introduced. Despite the marked increase in the number of membrane-protein structures solved using crystals grown by the lipid cubic phase or in meso method, only ten have been determined by SAD/MAD. This is likely to be a consequence of the technical difficulties associated with handling proteins and crystals in the sticky and viscous hosting mesophase that is usually incubated in glass sandwich plates for the purposes of crystallization. Here, a four-year campaign aimed at phasing the in meso structure of the integral membrane diacylglycerol kinase (DgkA) from Escherichia coli is reported. Heavy-atom labelling of this small hydrophobic enzyme was attempted by pre-labelling, co-crystallization, soaking, site-specific mercury binding to genetically engineered single-cysteine mutants and selenomethionine incorporation. Strategies and techniques for special handling are reported, as well as the typical results and the lessons learned for each of these approaches. In addition, an assay to assess the accessibility of cysteine residues in membrane proteins for mercury labelling is introduced. The various techniques and strategies described will provide a valuable reference for future experimental phasing of membrane proteins where crystals are grown by the lipid cubic phase method.

  12. The Metalloprotease Meprin β Is an Alternative β-Secretase of APP

    PubMed Central

    Becker-Pauly, Christoph; Pietrzik, Claus U.

    2017-01-01

    The membrane bound metalloprotease meprin β is important for collagen fibril assembly in connective tissue formation and for the detachment of the intestinal mucus layer for proper barrier function. Recent proteomic studies revealed dozens of putative new substrates of meprin β, including the amyloid precursor protein (APP). It was shown that APP is cleaved by meprin β in distinct ways, either at the β-secretase site resulting in increased levels of Aβ peptides, or at the N-terminus releasing 11 kDa, and 20 kDa peptide fragments. The latter event was discussed to be rather neuroprotective, whereas the ectodomain shedding of APP by meprin β reminiscent to BACE-1 is in line with the amyloid hypothesis of Alzheimer's disease, promoting neurodegeneration. The N-terminal 11 kDa and 20 kDa peptide fragments represent physiological cleavage products, since they are found in human brains under different diseased or non-diseased states, whereas these fragments are completely missing in brains of meprin β knock-out animals. Meprin β is not only a sheddase of adhesion molecules, such as APP, but was additionally demonstrated to cleave within the prodomain of ADAM10. Activated ADAM10, the α-secretase of APP, is then able to shed meprin β from the cell surface thereby abolishing the β-secretase activity. All together meprin β seems to be a novel player in APP processing events, even influencing other enzymes involved in APP cleavage. PMID:28105004

  13. Loss of Polo ameliorates APP-induced Alzheimer's disease-like symptoms in Drosophila.

    PubMed

    Peng, Fei; Zhao, Yu; Huang, Xirui; Chen, Changyan; Sun, Lili; Zhuang, Luming; Xue, Lei

    2015-11-24

    The amyloid precursor protein (APP) has been implicated in the pathogenesis of Alzheimer's disease (AD). Despite extensive studies, little is known about the regulation of APP's functions in vivo. Here we report that expression of human APP in Drosophila, in the same temporal-spatial pattern as its homolog APPL, induced morphological defects in wings and larval NMJ, larva and adult locomotion dysfunctions, male choice disorder and lifespan shortening. To identify additional genes that modulate APP functions, we performed a genetic screen and found that loss of Polo, a key regulator of cell cycle, partially suppressed APP-induced morphological and behavioral defects in larval and adult stages. Finally, we showed that eye-specific expression of APP induced retina degeneration and cell cycle re-entry, both phenotypes were mildly ameliorated by loss of Polo. These results suggest Polo is an important in vivo regulator of the pathological functions of APP, and provide insight into the role of cell cycle re-entry in AD pathogenesis.

  14. The Metalloprotease Meprin β Is an Alternative β-Secretase of APP.

    PubMed

    Becker-Pauly, Christoph; Pietrzik, Claus U

    2016-01-01

    The membrane bound metalloprotease meprin β is important for collagen fibril assembly in connective tissue formation and for the detachment of the intestinal mucus layer for proper barrier function. Recent proteomic studies revealed dozens of putative new substrates of meprin β, including the amyloid precursor protein (APP). It was shown that APP is cleaved by meprin β in distinct ways, either at the β-secretase site resulting in increased levels of Aβ peptides, or at the N-terminus releasing 11 kDa, and 20 kDa peptide fragments. The latter event was discussed to be rather neuroprotective, whereas the ectodomain shedding of APP by meprin β reminiscent to BACE-1 is in line with the amyloid hypothesis of Alzheimer's disease, promoting neurodegeneration. The N-terminal 11 kDa and 20 kDa peptide fragments represent physiological cleavage products, since they are found in human brains under different diseased or non-diseased states, whereas these fragments are completely missing in brains of meprin β knock-out animals. Meprin β is not only a sheddase of adhesion molecules, such as APP, but was additionally demonstrated to cleave within the prodomain of ADAM10. Activated ADAM10, the α-secretase of APP, is then able to shed meprin β from the cell surface thereby abolishing the β-secretase activity. All together meprin β seems to be a novel player in APP processing events, even influencing other enzymes involved in APP cleavage.

  15. Endogenous murine Aβ increases amyloid deposition in APP23 but not in APPPS1 transgenic mice.

    PubMed

    Mahler, Jasmin; Morales-Corraliza, Jose; Stolz, Julia; Skodras, Angelos; Radde, Rebecca; Duma, Carmen C; Eisele, Yvonne S; Mazzella, Matthew J; Wong, Harrison; Klunk, William E; Nilsson, K Peter R; Staufenbiel, Matthias; Mathews, Paul M; Jucker, Mathias; Wegenast-Braun, Bettina M

    2015-07-01

    Endogenous murine amyloid-β peptide (Aβ) is expressed in most Aβ precursor protein (APP) transgenic mouse models of Alzheimer's disease but its contribution to β-amyloidosis remains unclear. We demonstrate ∼ 35% increased cerebral Aβ load in APP23 transgenic mice compared with age-matched APP23 mice on an App-null background. No such difference was found for the much faster Aβ-depositing APPPS1 transgenic mouse model between animals with or without the murine App gene. Nevertheless, both APP23 and APPPS1 mice codeposited murine Aβ, and immunoelectron microscopy revealed a tight association of murine Aβ with human Aβ fibrils. Deposition of murine Aβ was considerably less efficient compared with the deposition of human Aβ indicating a lower amyloidogenic potential of murine Aβ in vivo. The amyloid dyes Pittsburgh Compound-B and pentamer formyl thiophene acetic acid did not differentiate between amyloid deposits consisting of human Aβ and deposits of mixed human-murine Aβ. Our data demonstrate a differential effect of murine Aβ on human Aβ deposition in different APP transgenic mice. The mechanistically complex interaction of human and mouse Aβ may affect pathogenesis of the models and should be considered when models are used for translational preclinical studies.

  16. The concentrations of inflammatory cytokines and acute-phase proteins in the peripheral blood and uterine washings in cows with pyometra.

    PubMed

    Brodzki, P; Kostro, K; Brodzki, A; Ziętek, J

    2015-06-01

    The development of pyometra in cows depends largely on the state of local immunity of the uterus. The objective of the study was to evaluate the concentration of the following proinflammatory cytokines: tumour necrosis factor (TNF-α) and interleukin-6 (IL-6); anti-inflammatory cytokine: interleukin-10 (IL-10); and acute-phase proteins (APPs): haptoglobin (Hp) and serum amyloid A (SAA), in serum and uterine washings in cows with pyometra and healthy animals. The study was performed on 20 cows divided into two groups based on the results of cytological and ultrasonographic tests: a pyometra and a healthy group (10 cows per group). Experimental material consisted of blood serum and uterine washings. The levels of the following cytokines, TNF-α, IL-6, IL-10 and APPs - Hp and SAA, in the study material were determined by ELISA. The results showed that the values of TNF-α, IL-6, IL-10 as well as SAA and Hp were significantly higher in serum of cows with pyometra compared to controls (p < 0.001). The uterine washings had significantly higher levels of IL-6, IL-10, and Hp in pyometra cows compared to the control (p < 0.001). Our results indicate that it is possible to monitor the course of pyometra in cows based on the evaluation of the concentration of cytokines and Hp in the serum and uterine washings. Simultaneous evaluation of selected indicators of antagonistic interaction can be helpful in determining the current status of local immunity of the uterus. On this basis, it could be possible to properly select an adjunctive therapy in the form of immunomodulating preparations.

  17. Nicastrin is required for APP but not Notch processing, while Aph-1 is dispensable for processing of both APP and Notch.

    PubMed

    Hu, Chen; Zeng, Linlin; Li, Ting; Meyer, Michael A; Cui, Mei-Zhen; Xu, Xuemin

    2015-12-30

    The γ-secretase complex is composed of at least four components: presenilin (PS1 or PS2), nicastrin (NCT), anterior pharynx-defective 1 (Aph-1), and presenilin enhancer 2 (pen-2). In this study, using knockout cell lines, our data demonstrated that knockout of NCT, as well as knockout of Pen-2, completely blocked γ-secretase-catalyzed processing of CTFα and CTFβ, the C-terminal fragments of β-amyloid precursor protein (APP) produced by α-secretase and β-secretase cleavages, respectively. Interestingly, in Aph-1-knockout cells CTFα and CTFβ were still processed by γ-secretase, indicating Aph-1 is dispensable for APP processing. Furthermore, our results indicate that Aph-1 as well as NCT is not absolutely required for Notch processing, suggesting that NCT is differentially required for APP and Notch processing. In addition, our data revealed that components of the γ-secretase complex are also important for proteasome- and lysosome-dependent degradation of APP and that endogenous APP is mostly degraded by lysosome while exogenous APP is mainly degraded by proteasome. This article is protected by copyright. All rights reserved.

  18. App Development Paradigms for Instructional Developers

    ERIC Educational Resources Information Center

    Luterbach, Kenneth J.; Hubbell, Kenneth R.

    2015-01-01

    To create instructional apps for desktop, laptop and mobile devices, developers must select a development tool. Tool selection is critical and complicated by the large number and variety of app development tools. One important criterion to consider is the type of development environment, which may primarily be visual or symbolic. Those distinct…

  19. Cool Apps: Productivity at Your Fingertips

    ERIC Educational Resources Information Center

    Flaherty, Bill

    2013-01-01

    In addition to listing apps and their value, this article focuses on ways people can be more productive by adopting certain workflows in several ways. Apps listed herein include those useful in calendaring, printing, photo-editing, image-recognition, image scanning, electronic signatures, and making and sharing lists and notes.

  20. Will HTML5 Kill the Native App?

    ERIC Educational Resources Information Center

    Fredette, Michelle

    2013-01-01

    For colleges and universities today, the question is no longer whether to develop a campus app or not. Instead, the debate has shifted to the best--and most cost-efficient--way to make campus applications accessible to the myriad devices and operating systems out there. Schools have a few options: They can develop multiple native app versions;…

  1. Is There an App for that?

    ERIC Educational Resources Information Center

    Douglas, Karen H.; Wojcik, Brian W.; Thompson, James R.

    2012-01-01

    Everyday technologies (e.g., iPods, iPads, and Smart Phones) other applications (apps) that can serve as supports to students with intellectual and related developmental disabilities. The extent to which apps that are currently on the market are aligned with the support needs of children was evaluated using the subscale framework of the…

  2. Analysis by a highly sensitive split luciferase assay of the regions involved in APP dimerization and its impact on processing.

    PubMed

    Decock, Marie; El Haylani, Laetitia; Stanga, Serena; Dewachter, Ilse; Octave, Jean-Noël; Smith, Steven O; Constantinescu, Stefan N; Kienlen-Campard, Pascal

    2015-01-01

    Alzheimer's disease (AD) is a neurodegenerative disease that causes progressive loss of cognitive functions, leading to dementia. Two types of lesions are found in AD brains: neurofibrillary tangles and senile plaques. The latter are composed mainly of the β-amyloid peptide (Aβ) generated by amyloidogenic processing of the amyloid precursor protein (APP). Several studies have suggested that dimerization of APP is closely linked to Aβ production. Nevertheless, the mechanisms controlling APP dimerization and their role in APP function are not known. Here we used a new luciferase complementation assay to analyze APP dimerization and unravel the involvement of its three major domains: the ectodomain, the transmembrane domain and the intracellular domain. Our results indicate that within cells full-length APP dimerizes more than its α and β C-terminal fragments, confirming the pivotal role of the ectodomain in this process. Dimerization of the APP transmembrane (TM) domain has been reported to regulate processing at the γ-cleavage site. We show that both non-familial and familial AD mutations in the TM GXXXG motifs strongly modulate Aβ production, but do not consistently change dimerization of the C-terminal fragments. Finally, we found for the first time that removal of intracellular domain strongly increases APP dimerization. Increased APP dimerization is linked to increased non-amyloidogenic processing.

  3. Amyloidogenic Processing but not AICD Production Requires a Precisely Oriented APP Dimer Assembled by Transmembrane GXXXG Motifs

    PubMed Central

    Kienlen-Campard, Pascal; Tasiaux, Bernadette; Van Hees, Joanne; Li, Mingli; Huysseune, Sandra; Sato, Takeshi; Fei, Jeffrey Z.; Aimoto, Saburo; Courtoy, Pierre J.; Smith, Steven O.; Constantinescu, Stefan N.; Octave, Jean-Noël

    2009-01-01

    The β-amyloid peptide (Aβ) is the major constituent of the amyloid core of senile plaques found in the brain of patients with Alzheimer's disease (AD). Aβ is produced by the sequential cleavage of the Amyloid Precursor Protein (APP) by β- and γ-secretases. Cleavage of APP by γ-secretase also generates the APP Intracellular C-terminal Domain (AICD) peptide, which might be involved in regulation of gene transcription. APP contains three glycine-xxx-glycine (GxxxG) motifs in its juxtamembrane and transmembrane (TM) regions. Such motifs are known to promote dimerization via close apposition of TM sequences. We demonstrate that pairwise replacement of glycines by leucines or isoleucines, but not alanines, in a GxxxG motif led to a drastic reduction of Aβ40 and Aβ42 secretion. β-Cleavage of mutant APP was not inhibited, and reduction of Aβ secretion resulted from inhibition of γ-cleavage. It was anticipated that decreased γ-cleavage of mutant APP would result from inhibition of its dimerization. Surprisingly, mutations of the GxxxG motif actually enhanced dimerization of the APP C-terminal fragments, possibly via a different TM α-helical interface. Increased dimerization of the TM APP C-terminal domain did not affect AICD production. These results clearly demonstrate that both orientation and dimerization of the APP TM domain differently affect Aβ and AICD production. PMID:18201969

  4. Low-abundant protein extraction from complex protein sample using a novel continuous aqueous two-phase systems device.

    PubMed

    Vázquez-Villegas, Patricia; Espitia-Saloma, Edith; Rito-Palomares, Marco; Aguilar, Oscar

    2013-01-01

    The present work describes the application of a novel continuous aqueous two-phase system prototype for the recovery of biomolecules. The prototype is an alternative platform for protein recovery and α-amylase from soybean extracts was used as a model system. The system was selected as an example of low-abundant protein present in complex mixtures. Compared with batch systems, continuous operation in this prototype seems to increase partition coefficient with higher recovery efficiencies. Processing time is reduced at least three times in the continuous system when compared to batch mode, while hold up (volumetric quantity of the opposing phase in a determined phase sample) decreases with decreasing phases flow. Furthermore, similar partition coefficient (Kp > 4) with a higher top phase enzyme recovery (81%) is also obtained in this system probably due to better contact surface between phases, compared with that obtained in batch (79%). A continuous aqueous two-phase system process with purification factor 40-fold higher than batch experiments was achieved. These preliminary results exhibit the potential of continuous systems for the recovery of low-abundant proteins from complex mixtures. The promising performance of this prototype can raise the attention of the industry for the adoption of aqueous two-phase system processes.

  5. APP intracellular domain derived from amyloidogenic β- and γ-secretase cleavage regulates neprilysin expression

    PubMed Central

    Grimm, Marcus O. W.; Mett, Janine; Stahlmann, Christoph P.; Grösgen, Sven; Haupenthal, Viola J.; Blümel, Tamara; Hundsdörfer, Benjamin; Zimmer, Valerie C.; Mylonas, Nadine T.; Tanila, Heikki; Müller, Ulrike; Grimm, Heike S.; Hartmann, Tobias

    2015-01-01

    Alzheimer's disease (AD) is characterized by an accumulation of Amyloid-β (Aβ), released by sequential proteolytic processing of the amyloid precursor protein (APP) by β - and γ-secretase. Aβ peptides can aggregate, leading to toxic Aβ oligomers and amyloid plaque formation. Aβ accumulation is not only dependent on de novo synthesis but also on Aβ degradation. Neprilysin (NEP) is one of the major enzymes involved in Aβ degradation. Here we investigate the molecular mechanism of NEP regulation, which is up to now controversially discussed to be affected by APP processing itself. We found that NEP expression is highly dependent on the APP intracellular domain (AICD), released by APP processing. Mouse embryonic fibroblasts devoid of APP processing, either by the lack of the catalytically active subunit of the γ-secretase complex [presenilin (PS) 1/2] or by the lack of APP and the APP-like protein 2 (APLP2), showed a decreased NEP expression, activity and protein level. Similar results were obtained by utilizing cells lacking a functional AICD domain (APPΔCT15) or expressing mutations in the genes encoding for PS1. AICD supplementation or retransfection with an AICD encoding plasmid could rescue the down-regulation of NEP further strengthening the link between AICD and transcriptional NEP regulation, in which Fe65 acts as an important adaptor protein. Especially AICD generated by the amyloidogenic pathway seems to be more involved in the regulation of NEP expression. In line, analysis of NEP gene expression in vivo in six transgenic AD mouse models (APP and APLP2 single knock-outs, APP/APLP2 double knock-out, APP-swedish, APP-swedish/PS1Δexon9, and APPΔCT15) confirmed the results obtained in cell culture. In summary, in the present study we clearly demonstrate an AICD-dependent regulation of the Aβ-degrading enzyme NEP in vitro and in vivo and elucidate the underlying mechanisms that might be beneficial to develop new therapeutic strategies for the

  6. APP intracellular domain derived from amyloidogenic β- and γ-secretase cleavage regulates neprilysin expression.

    PubMed

    Grimm, Marcus O W; Mett, Janine; Stahlmann, Christoph P; Grösgen, Sven; Haupenthal, Viola J; Blümel, Tamara; Hundsdörfer, Benjamin; Zimmer, Valerie C; Mylonas, Nadine T; Tanila, Heikki; Müller, Ulrike; Grimm, Heike S; Hartmann, Tobias

    2015-01-01

    Alzheimer's disease (AD) is characterized by an accumulation of Amyloid-β (Aβ), released by sequential proteolytic processing of the amyloid precursor protein (APP) by β - and γ-secretase. Aβ peptides can aggregate, leading to toxic Aβ oligomers and amyloid plaque formation. Aβ accumulation is not only dependent on de novo synthesis but also on Aβ degradation. Neprilysin (NEP) is one of the major enzymes involved in Aβ degradation. Here we investigate the molecular mechanism of NEP regulation, which is up to now controversially discussed to be affected by APP processing itself. We found that NEP expression is highly dependent on the APP intracellular domain (AICD), released by APP processing. Mouse embryonic fibroblasts devoid of APP processing, either by the lack of the catalytically active subunit of the γ-secretase complex [presenilin (PS) 1/2] or by the lack of APP and the APP-like protein 2 (APLP2), showed a decreased NEP expression, activity and protein level. Similar results were obtained by utilizing cells lacking a functional AICD domain (APPΔCT15) or expressing mutations in the genes encoding for PS1. AICD supplementation or retransfection with an AICD encoding plasmid could rescue the down-regulation of NEP further strengthening the link between AICD and transcriptional NEP regulation, in which Fe65 acts as an important adaptor protein. Especially AICD generated by the amyloidogenic pathway seems to be more involved in the regulation of NEP expression. In line, analysis of NEP gene expression in vivo in six transgenic AD mouse models (APP and APLP2 single knock-outs, APP/APLP2 double knock-out, APP-swedish, APP-swedish/PS1Δexon9, and APPΔCT15) confirmed the results obtained in cell culture. In summary, in the present study we clearly demonstrate an AICD-dependent regulation of the Aβ-degrading enzyme NEP in vitro and in vivo and elucidate the underlying mechanisms that might be beneficial to develop new therapeutic strategies for the

  7. Aqueous two-phase system based on natural quaternary ammonium compounds for the extraction of proteins.

    PubMed

    Zeng, Chao-Xi; Xin, Rui-Pu; Qi, Sui-Jian; Yang, Bo; Wang, Yong-Hua

    2016-02-01

    Aqueous two-phase systems, based on the use of natural quaternary ammonium compounds, were developed to establish a benign biotechnological route for efficient protein separation. In this study, aqueous two-phase systems of two natural resources betaine and choline with polyethyleneglycol (PEG400/600) or inorganic salts (K2 HPO4 /K3 PO4 ) were formed. It was shown that in the K2 HPO4 -containing aqueous two-phase system, hydrophobic interactions were an important driving force of protein partitioning, while protein size played a vital role in aqueous two-phase systems that contained polyethylene glycol. An extraction efficiency of more than 90% for bovine serum albumin in the betaine/K2 HPO4 aqueous two-phase system can be obtained, and this betaine-based aqueous two-phase system provided a gentle and stable environment for the protein. In addition, after investigation of the cluster phenomenon in the betaine/K2 HPO4 aqueous two-phase systems, it was suggested that this phenomenon also played a significant role for protein extraction in this system. The development of aqueous two-phase systems based on natural quaternary ammonium compounds not only provided an effective and greener method of aqueous two-phase system to meet the requirements of green chemistry but also may help to solve the mystery of the compartmentalization of biomolecules in cells.

  8. Smart apps for the smart plastic surgeon.

    PubMed

    Venkataram, Aniketh; Ellur, Sunderraj; Kujur, Abha Rani; Joseph, Vijay

    2015-01-01

    Smartphones have the ability to benefit plastic surgeons in all aspects of patient care and education. With the sheer number of applications available and more being created everyday, it is easy to miss out on apps which could be of great relevance. Moreover, the range of android applications available has not been extensively discussed in the literature. To this end, we have compiled an exhaustive list of android smartphone applications, which we feel can help our day to day functioning. The apps have been extensively reviewed and neatly described along with all their potential uses. In addition, we have made an effort to highlight 'non-medical' or efficiency apps which can improve departmental functioning. These apps have not been described in prior articles, and their functionality might not be known to all. We believe that the technology savvy plastic surgeon can make maximum use of these apps to his benefit.

  9. Smart apps for the smart plastic surgeon

    PubMed Central

    Venkataram, Aniketh; Ellur, Sunderraj; Kujur, Abha Rani; Joseph, Vijay

    2015-01-01

    Smartphones have the ability to benefit plastic surgeons in all aspects of patient care and education. With the sheer number of applications available and more being created everyday, it is easy to miss out on apps which could be of great relevance. Moreover, the range of android applications available has not been extensively discussed in the literature. To this end, we have compiled an exhaustive list of android smartphone applications, which we feel can help our day to day functioning. The apps have been extensively reviewed and neatly described along with all their potential uses. In addition, we have made an effort to highlight ‘non-medical’ or efficiency apps which can improve departmental functioning. These apps have not been described in prior articles, and their functionality might not be known to all. We believe that the technology savvy plastic surgeon can make maximum use of these apps to his benefit. PMID:25991890

  10. Cell Biology Apps for Apple Devices

    PubMed Central

    Stark, Louisa A.

    2012-01-01

    Apps for touch-pad devices hold promise for guiding and supporting learning. Students may use them in the classroom or on their own for didactic instruction, just-in-time learning, or review. Since Apple touch-pad devices (i.e., iPad and iPhone) have a substantial share of the touch-pad device market (Campbell, 2012), this Feature will explore cell biology apps available from the App Store. My review includes iPad and iPhone apps available in June 2012, but does not include courses, lectures, podcasts, audiobooks, texts, or other books. I rated each app on a five-point scale (1 star = lowest; 5 stars = highest) for educational and production values; I also provide an overall score. PMID:22949420

  11. Forensic Taxonomy of Android Social Apps.

    PubMed

    Azfar, Abdullah; Choo, Kim-Kwang Raymond; Liu, Lin

    2017-03-01

    An Android social app taxonomy incorporating artifacts that are of forensic interest will enable users and forensic investigators to identify the personally identifiable information (PII) stored by the apps. In this study, 30 popular Android social apps were examined. Artifacts of forensic interest (e.g., contacts lists, chronology of messages, and timestamp of an added contact) were recovered. In addition, images were located, and Facebook token strings used to tie account identities and gain access to information entered into Facebook by a user were identified. Based on the findings, a two-dimensional taxonomy of the forensic artifacts of the social apps is proposed. A comparative summary of existing forensic taxonomies of different categories of Android apps, designed to facilitate timely collection and analysis of evidentiary materials from Android devices, is presented.

  12. Cell biology apps for Apple devices.

    PubMed

    Stark, Louisa A

    2012-01-01

    Apps for touch-pad devices hold promise for guiding and supporting learning. Students may use them in the classroom or on their own for didactic instruction, just-in-time learning, or review. Since Apple touch-pad devices (i.e., iPad and iPhone) have a substantial share of the touch-pad device market (Campbell, 2012), this Feature will explore cell biology apps available from the App Store. My review includes iPad and iPhone apps available in June 2012, but does not include courses, lectures, podcasts, audiobooks, texts, or other books. I rated each app on a five-point scale (1 star = lowest; 5 stars = highest) for educational and production values; I also provide an overall score.

  13. A molecular dynamics study of the binary complexes of APP, JIP1, and the cargo binding domain of KLC.

    PubMed

    Taylor, Cooper A; Miller, Bill R; Shah, Soleil S; Parish, Carol A

    2017-02-01

    Mutations in the amyloid precursor protein (APP) are responsible for the formation of amyloid-β peptides. These peptides play a role in Alzheimer's and other dementia-related diseases. The cargo binding domain of the kinesin-1 light chain motor protein (KLC1) may be responsible for transporting APP either directly or via interaction with C-jun N-terminal kinase-interacting protein 1 (JIP1). However, to date there has been no direct experimental or computational assessment of such binding at the atomistic level. We used molecular dynamics and free energy estimations to gauge the affinity for the binary complexes of KLC1, APP, and JIP1. We find that all binary complexes (KLC1:APP, KLC1:JIP1, and APP:JIP1) contain conformations with favorable binding free energies. For KLC1:APP the inclusion of approximate entropies reduces the favorability. This is likely due to the flexibility of the 42-residue APP protein. In all cases we analyze atomistic/residue driving forces for favorable interactions. Proteins 2017; 85:221-234. © 2016 Wiley Periodicals, Inc.

  14. Differential surface deposition of complement proteins on logarithmic and stationary phase Leishmania chagasi promastigotes.

    PubMed

    Ramer-Tait, Amanda E; Lei, Soi Meng; Bellaire, Bryan H; Beetham, Jeffrey K

    2012-12-01

    Previous works demonstrated that various species of Leishmania promastigotes exhibit differential sensitivity to complement-mediated lysis (CML) during development. Upon exposure to normal human serum (NHS), cultures of Leishmania chagasi promastigotes recently isolated from infected hamsters (fewer than 5 in vitro passages) are CML-sensitive when in the logarithmic growth phase but become CML-resistant upon transition to the stationary culture phase. Visualization by light and electron microscopy revealed dramatic morphological differences between promastigotes from the 2 culture phases following exposure to NHS. Flow cytometric analysis demonstrated that surface deposition of the complement components C3, C5, and C9 correlated inversely with promastigote CML-resistance. The highest levels of complement protein surface accumulation were observed for logarithmic phase promastigotes, while stationary phase promastigotes adsorbed the least amount of complement proteins. Additionally, fluorescence microscopy revealed that C3 and C5 localized in a fairly uniform pattern to the plasma membrane of promastigotes from logarithmic phase cultures, while the staining of promastigotes from stationary phase cultures was indistinguishable from background. By Western blot analysis, high levels of the complement proteins C3, C5, and C9 were detected in the total lysates of NHS-exposed logarithmic phase L. chagasi promastigotes, relative to NHS-exposed stationary phase promastigotes; this finding indicates that the low levels of C3 and C5 seen on the surface of stationary phase promastigotes were not due to protein uptake/internalization. Together, these data demonstrate the differential deposition of complement proteins on the surfaces of logarithmic and stationary phase L. chagasi promastigotes. The data support a model wherein stationary phase L. chagasi promastigotes resist CML by limiting the deposition of C3 and its derivatives, which, in turn, limit surface levels of

  15. Intraneuronal APP and extracellular Aβ independently cause dendritic spine pathology in transgenic mouse models of Alzheimer's disease.

    PubMed

    Zou, Chengyu; Montagna, Elena; Shi, Yuan; Peters, Finn; Blazquez-Llorca, Lidia; Shi, Song; Filser, Severin; Dorostkar, Mario M; Herms, Jochen

    2015-06-01

    Alzheimer's disease (AD) is thought to be caused by accumulation of amyloid-β protein (Aβ), which is a cleavage product of amyloid precursor protein (APP). Transgenic mice overexpressing APP have been used to recapitulate amyloid-β pathology. Among them, APP23 and APPswe/PS1deltaE9 (deltaE9) mice are extensively studied. APP23 mice express APP with Swedish mutation and develop amyloid plaques late in their life, while cognitive deficits are observed in young age. In contrast, deltaE9 mice with mutant APP and mutant presenilin-1 develop amyloid plaques early but show typical cognitive deficits in old age. To unveil the reasons for different progressions of cognitive decline in these commonly used mouse models, we analyzed the number and turnover of dendritic spines as important structural correlates for learning and memory. Chronic in vivo two-photon imaging in apical tufts of layer V pyramidal neurons revealed a decreased spine density in 4-5-month-old APP23 mice. In age-matched deltaE9 mice, in contrast, spine loss was only observed on cortical dendrites that were in close proximity to amyloid plaques. In both cases, the reduced spine density was caused by decreased spine formation. Interestingly, the patterns of alterations in spine morphology differed between these two transgenic mouse models. Moreover, in APP23 mice, APP was found to accumulate intracellularly and its content was inversely correlated with the absolute spine density and the relative number of mushroom spines. Collectively, our results suggest that different pathological mechanisms, namely an intracellular accumulation of APP or extracellular amyloid plaques, may lead to spine abnormalities in young adult APP23 and deltaE9 mice, respectively. These distinct features, which may represent very different mechanisms of synaptic failure in AD, have to be taken into consideration when translating results from animal studies to the human disease.

  16. Using the Relevance Vector Machine Model Combined with Local Phase Quantization to Predict Protein-Protein Interactions from Protein Sequences.

    PubMed

    An, Ji-Yong; Meng, Fan-Rong; You, Zhu-Hong; Fang, Yu-Hong; Zhao, Yu-Jun; Zhang, Ming

    2016-01-01

    We propose a novel computational method known as RVM-LPQ that combines the Relevance Vector Machine (RVM) model and Local Phase Quantization (LPQ) to predict PPIs from protein sequences. The main improvements are the results of representing protein sequences using the LPQ feature representation on a Position Specific Scoring Matrix (PSSM), reducing the influence of noise using a Principal Component Analysis (PCA), and using a Relevance Vector Machine (RVM) based classifier. We perform 5-fold cross-validation experiments on Yeast and Human datasets, and we achieve very high accuracies of 92.65% and 97.62%, respectively, which is significantly better than previous works. To further evaluate the proposed method, we compare it with the state-of-the-art support vector machine (SVM) classifier on the Yeast dataset. The experimental results demonstrate that our RVM-LPQ method is obviously better than the SVM-based method. The promising experimental results show the efficiency and simplicity of the proposed method, which can be an automatic decision support tool for future proteomics research.

  17. Using the Relevance Vector Machine Model Combined with Local Phase Quantization to Predict Protein-Protein Interactions from Protein Sequences

    PubMed Central

    An, Ji-Yong; Meng, Fan-Rong; You, Zhu-Hong; Fang, Yu-Hong; Zhao, Yu-Jun; Zhang, Ming

    2016-01-01

    We propose a novel computational method known as RVM-LPQ that combines the Relevance Vector Machine (RVM) model and Local Phase Quantization (LPQ) to predict PPIs from protein sequences. The main improvements are the results of representing protein sequences using the LPQ feature representation on a Position Specific Scoring Matrix (PSSM), reducing the influence of noise using a Principal Component Analysis (PCA), and using a Relevance Vector Machine (RVM) based classifier. We perform 5-fold cross-validation experiments on Yeast and Human datasets, and we achieve very high accuracies of 92.65% and 97.62%, respectively, which is significantly better than previous works. To further evaluate the proposed method, we compare it with the state-of-the-art support vector machine (SVM) classifier on the Yeast dataset. The experimental results demonstrate that our RVM-LPQ method is obviously better than the SVM-based method. The promising experimental results show the efficiency and simplicity of the proposed method, which can be an automatic decision support tool for future proteomics research. PMID:27314023

  18. Screening for Small Molecule Inhibitors of Statin-Induced APP C-terminal Toxic Fragment Production.

    PubMed

    Poksay, Karen S; Sheffler, Douglas J; Spilman, Patricia; Campagna, Jesus; Jagodzinska, Barbara; Descamps, Olivier; Gorostiza, Olivia; Matalis, Alex; Mullenix, Michael; Bredesen, Dale E; Cosford, Nicholas D P; John, Varghese

    2017-01-01

    Alzheimer's disease (AD) is characterized by neuronal and synaptic loss. One process that could contribute to this loss is the intracellular caspase cleavage of the amyloid precursor protein (APP) resulting in release of the toxic C-terminal 31-amino acid peptide APP-C31 along with the production of APPΔC31, full-length APP minus the C-terminal 31 amino acids. We previously found that a mutation in APP that prevents this caspase cleavage ameliorated synaptic loss and cognitive impairment in a murine AD model. Thus, inhibition of this cleavage is a reasonable target for new therapeutic development. In order to identify small molecules that inhibit the generation of APP-C31, we first used an APPΔC31 cleavage site-specific antibody to develop an AlphaLISA to screen several chemical compound libraries for the level of N-terminal fragment production. This antibody was also used to develop an ELISA for validation studies. In both high throughput screening (HTS) and validation testing, the ability of compounds to inhibit simvastatin- (HTS) or cerivastatin- (validation studies) induced caspase cleavage at the APP-D720 cleavage site was determined in Chinese hamster ovary (CHO) cells stably transfected with wildtype (wt) human APP (CHO-7W). Several compounds, as well as control pan-caspase inhibitor Q-VD-OPh, inhibited APPΔC31 production (measured fragment) and rescued cell death in a dose-dependent manner. The effective compounds fell into several classes including SERCA inhibitors, inhibitors of Wnt signaling, and calcium channel antagonists. Further studies are underway to evaluate the efficacy of lead compounds - identified here using cells and tissues expressing wt human APP - in mouse models of AD expressing mutated human APP, as well as to identify additional compounds and determine the mechanisms by which they exert their effects.

  19. Screening for Small Molecule Inhibitors of Statin-Induced APP C-terminal Toxic Fragment Production

    PubMed Central

    Poksay, Karen S.; Sheffler, Douglas J.; Spilman, Patricia; Campagna, Jesus; Jagodzinska, Barbara; Descamps, Olivier; Gorostiza, Olivia; Matalis, Alex; Mullenix, Michael; Bredesen, Dale E.; Cosford, Nicholas D. P.; John, Varghese

    2017-01-01

    Alzheimer’s disease (AD) is characterized by neuronal and synaptic loss. One process that could contribute to this loss is the intracellular caspase cleavage of the amyloid precursor protein (APP) resulting in release of the toxic C-terminal 31-amino acid peptide APP-C31 along with the production of APPΔC31, full-length APP minus the C-terminal 31 amino acids. We previously found that a mutation in APP that prevents this caspase cleavage ameliorated synaptic loss and cognitive impairment in a murine AD model. Thus, inhibition of this cleavage is a reasonable target for new therapeutic development. In order to identify small molecules that inhibit the generation of APP-C31, we first used an APPΔC31 cleavage site-specific antibody to develop an AlphaLISA to screen several chemical compound libraries for the level of N-terminal fragment production. This antibody was also used to develop an ELISA for validation studies. In both high throughput screening (HTS) and validation testing, the ability of compounds to inhibit simvastatin- (HTS) or cerivastatin- (validation studies) induced caspase cleavage at the APP-D720 cleavage site was determined in Chinese hamster ovary (CHO) cells stably transfected with wildtype (wt) human APP (CHO-7W). Several compounds, as well as control pan-caspase inhibitor Q-VD-OPh, inhibited APPΔC31 production (measured fragment) and rescued cell death in a dose-dependent manner. The effective compounds fell into several classes including SERCA inhibitors, inhibitors of Wnt signaling, and calcium channel antagonists. Further studies are underway to evaluate the efficacy of lead compounds – identified here using cells and tissues expressing wt human APP – in mouse models of AD expressing mutated human APP, as well as to identify additional compounds and determine the mechanisms by which they exert their effects. PMID:28261092

  20. Quantum Dots-based Reverse Phase Protein Microarray

    SciTech Connect

    Shingyoji, Masato; Gerion, Daniele; Pinkel, Dan; Gray, Joe W.; Chen, Fanqing

    2005-07-15

    CdSe nanocrystals, also called quantum dots (Qdots) are a novel class of fluorophores, which have a diameter of a few nanometers and possess high quantum yield, tunable emission wavelength and photostability. They are an attractive alternative to conventional fluorescent dyes. Quantum dots can be silanized to be soluble in aqueous solution under biological conditions, and thus be used in bio-detection. In this study, we established a novel Qdot-based technology platform that can perform accurate and reproducible quantification of protein concentration in a crude cell lysate background. Protein lysates have been spiked with a target protein, and a dilution series of the cell lysate with a dynamic range of three orders of magnitude has been used for this proof-of-concept study. The dilution series has been spotted in microarray format, and protein detection has been achieved with a sensitivity that is at least comparable to standard commercial assays, which are based on horseradish peroxidase (HRP) catalyzed diaminobenzidine (DAB) chromogenesis. The data obtained through the Qdot method has shown a close linear correlation between relative fluorescence unit and relative protein concentration. The Qdot results are in almost complete agreement with data we obtained with the well-established HRP-DAB colorimetric array (R{sup 2} = 0.986). This suggests that Qdots can be used for protein quantification in microarray format, using the platform presented here.

  1. Building a Mobile HIV Prevention App for Men Who Have Sex With Men: An Iterative and Community-Driven Process

    PubMed Central

    McDougal, Sarah J; Sullivan, Patrick S; Stekler, Joanne D; Stephenson, Rob

    2015-01-01

    Background Gay, bisexual, and other men who have sex with men (MSM) account for a disproportionate burden of new HIV infections in the United States. Mobile technology presents an opportunity for innovative interventions for HIV prevention. Some HIV prevention apps currently exist; however, it is challenging to encourage users to download these apps and use them regularly. An iterative research process that centers on the community’s needs and preferences may increase the uptake, adherence, and ultimate effectiveness of mobile apps for HIV prevention. Objective The aim of this paper is to provide a case study to illustrate how an iterative community approach to a mobile HIV prevention app can lead to changes in app content to appropriately address the needs and the desires of the target community. Methods In this three-phase study, we conducted focus group discussions (FGDs) with MSM and HIV testing counselors in Atlanta, Seattle, and US rural regions to learn preferences for building a mobile HIV prevention app. We used data from these groups to build a beta version of the app and theater tested it in additional FGDs. A thematic data analysis examined how this approach addressed preferences and concerns expressed by the participants. Results There was an increased willingness to use the app during theater testing than during the first phase of FGDs. Many concerns that were identified in phase one (eg, disagreements about reminders for HIV testing, concerns about app privacy) were considered in building the beta version. Participants perceived these features as strengths during theater testing. However, some disagreements were still present, especially regarding the tone and language of the app. Conclusions These findings highlight the benefits of using an interactive and community-driven process to collect data on app preferences when building a mobile HIV prevention app. Through this process, we learned how to be inclusive of the larger MSM population without

  2. App Chronic Disease Checklist: Protocol to Evaluate Mobile Apps for Chronic Disease Self-Management

    PubMed Central

    Anderson, Kevin; Burford, Oksana

    2016-01-01

    Background The availability of mobile health apps for self-care continues to increase. While little evidence of their clinical impact has been published, there is general agreement among health authorities and authors that consumers’ use of health apps assist in self-management and potentially clinical decision making. A consumer’s sustained engagement with a health app is dependent on the usability and functionality of the app. While numerous studies have attempted to evaluate health apps, there is a paucity of published methods that adequately recognize client experiences in the academic evaluation of apps for chronic conditions. Objective This paper reports (1) a protocol to shortlist health apps for academic evaluation, (2) synthesis of a checklist to screen health apps for quality and reliability, and (3) a proposed method to theoretically evaluate usability of health apps, with a view towards identifying one or more apps suitable for clinical assessment. Methods A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram was developed to guide the selection of the apps to be assessed. The screening checklist was thematically synthesized with reference to recurring constructs in published checklists and related materials for the assessment of health apps. The checklist was evaluated by the authors for face and construct validity. The proposed method for evaluation of health apps required the design of procedures for raters of apps, dummy data entry to test the apps, and analysis of raters’ scores. Results The PRISMA flow diagram comprises 5 steps: filtering of duplicate apps; eliminating non-English apps; removing apps requiring purchase, filtering apps not updated within the past year; and separation of apps into their core functionality. The screening checklist to evaluate the selected apps was named the App Chronic Disease Checklist, and comprises 4 sections with 6 questions in each section. The validity check verified

  3. Electrostatic Properties of Phase-Separating Bovine Lens Proteins.

    NASA Astrophysics Data System (ADS)

    Kovach, Ian Shand

    1992-01-01

    Acid-base titration experiments were conducted to determine the net charge on four bovine lens proteins: gamma_{rm II}, gamma_{rm IIIa}, gamma_{rm IIIb}, gamma_{rm IV}. In addition to the dependence of protein charge on pH, the effects of ionic strength and identity on protein charge were investigated. Titration curves were obtained in 0.1 M KCl, 0.1 M NaCl, 0.1 M NaBr, and 0.01 M KCl. Three theoretical methods, the Linderstrom-Lang model, a modification of the Linderstrom-Lang model which does not linearize the Poisson-Boltzmann equation, and the Kirkwood-Tanford model were used to correct intrinsic proton binding energies in an effort to predict protein charge as a function of solution conditions. The electrostatic interaction energy between protein and solvent was determined using the Linderstrom-Lang model. The acid-base titration curves of the four proteins were found to be very similar, with the exception of basic range titration of gamma_{rm IIIb} which exhibited slightly greater negative charge near pH 10. No evidence of protein charge dependence on the identity of electrolyte was observed. A dependence of protein charge on ionic strength was observed. Decreasing ionic strength was found to correlate with decreasing magnitude of net protein charge at a given pH. The theoretical Linderstrom-Lang titration curves were found to be in fair agreement with the experimental results over a pH range of 5 to 11, and in poor agreement in the pH extremes. The nonlinearized variation of the Linderstrom-Lang model was found to be in good agreement with the titration curves from pH 2 to pH 11. The theoretical Kirkwood-Tanford titration curves were determined for gamma_{rm II} and also found to be in excellent agreement with experimental results. The precise location of protein charge on gamma_{rm II}, as a function of pH, was determined using the Kirkwood-Tanford model. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617

  4. Effects of Folic Acid on Secretases Involved in Aβ Deposition in APP/PS1 Mice

    PubMed Central

    Tian, Tian; Bai, Dong; Li, Wen; Huang, Guo-Wei; Liu, Huan

    2016-01-01

    Alzheimer’s disease (AD) is the most common type of dementia. Amyloid-β protein (Aβ) is identified as the core protein of neuritic plaques. Aβ is generated by the sequential cleavage of the amyloid precursor protein (APP) via the APP cleaving enzyme (α-secretase, or β-secretase) and γ-secretase. Previous studies indicated that folate deficiency elevated Aβ deposition in APP/PS1 mice, and this rise was prevented by folic acid. In the present study, we aimed to investigate whether folic acid could influence the generation of Aβ by regulating α-, β-, and γ-secretase. Herein, we demonstrated that folic acid reduced the deposition of Aβ42 in APP/PS1 mice brain by decreasing the mRNA and protein expressions of β-secretase [beta-site APP-cleaving enzyme 1 (BACE1)] and γ-secretase complex catalytic component—presenilin 1 (PS1)—in APP/PS1 mice brain. Meanwhile, folic acid increased the levels of ADAM9 and ADAM10, which are important α-secretases in ADAM (a disintegrin and metalloprotease) family. However, folic acid has no impact on the protein expression of nicastrin (Nct), another component of γ-secretase complex. Moreover, folic acid regulated the expression of miR-126-3p and miR-339-5p, which target ADAM9 and BACE1, respectively. Taken together, the effect of folic acid on Aβ deposition may relate to making APP metabolism through non-amyloidogenic pathway by decreasing β-secretase and increasing α-secretase. MicroRNA (miRNA) may involve in the regulation mechanism of folic acid on secretase expression. PMID:27618097

  5. Effects of Folic Acid on Secretases Involved in Aβ Deposition in APP/PS1 Mice.

    PubMed

    Tian, Tian; Bai, Dong; Li, Wen; Huang, Guo-Wei; Liu, Huan

    2016-09-09

    Alzheimer's disease (AD) is the most common type of dementia. Amyloid-β protein (Aβ) is identified as the core protein of neuritic plaques. Aβ is generated by the sequential cleavage of the amyloid precursor protein (APP) via the APP cleaving enzyme (α-secretase, or β-secretase) and γ-secretase. Previous studies indicated that folate deficiency elevated Aβ deposition in APP/PS1 mice, and this rise was prevented by folic acid. In the present study, we aimed to investigate whether folic acid could influence the generation of Aβ by regulating α-, β-, and γ-secretase. Herein, we demonstrated that folic acid reduced the deposition of Aβ42 in APP/PS1 mice brain by decreasing the mRNA and protein expressions of β-secretase [beta-site APP-cleaving enzyme 1 (BACE1)] and γ-secretase complex catalytic component-presenilin 1 (PS1)-in APP/PS1 mice brain. Meanwhile, folic acid increased the levels of ADAM9 and ADAM10, which are important α-secretases in ADAM (a disintegrin and metalloprotease) family. However, folic acid has no impact on the protein expression of nicastrin (Nct), another component of γ-secretase complex. Moreover, folic acid regulated the expression of miR-126-3p and miR-339-5p, which target ADAM9 and BACE1, respectively. Taken together, the effect of folic acid on Aβ deposition may relate to making APP metabolism through non-amyloidogenic pathway by decreasing β-secretase and increasing α-secretase. MicroRNA (miRNA) may involve in the regulation mechanism of folic acid on secretase expression.

  6. Prediction of salt effects on protein phase behavior by HIC retention and thermal stability.

    PubMed

    Baumgartner, Kai; Großhans, Steffen; Schütz, Juliane; Suhm, Susanna; Hubbuch, Jürgen

    2016-09-05

    In the biopharmaceutical industry it is mandatory to know and ensure the correct protein phase state as a critical quality attribute in every process step. Unwanted protein precipitation or crystallization can lead to column, pipe or filter blocking. In formulation, the formation of aggregates can even be lethal when injected into the patient. The typical methodology to illustrate protein phase states is the generation of protein phase diagrams. Commonly, protein phase behavior is shown in dependence of protein and precipitant concentration. Despite using high-throughput methods for the generation of phase diagrams, the time necessary to reach equilibrium is the bottleneck. Faster methods to predict protein phase behavior are desirable. In this study, hydrophobic interaction chromatography retention times were correlated to crystal size and form. High-throughput thermal stability measurements (melting and aggregation temperatures), using an Optim(®)2 system, were successfully correlated to glucose isomerase stability. By using hydrophobic interaction chromatography and thermal stability determinations, glucose isomerase conformational and colloidal stability were successfully predicted for different salts in a specific pH range.

  7. Cholesterol accumulation in Niemann Pick type C (NPC) model cells causes a shift in APP localization to lipid rafts

    SciTech Connect

    Kosicek, Marko; Malnar, Martina; Goate, Alison; Hecimovic, Silva

    2010-03-12

    It has been suggested that cholesterol may modulate amyloid-{beta} (A{beta}) formation, a causative factor of Alzheimer's disease (AD), by regulating distribution of the three key proteins in the pathogenesis of AD ({beta}-amyloid precursor protein (APP), {beta}-secretase (BACE1) and/or presenilin 1 (PS1)) within lipid rafts. In this work we tested whether cholesterol accumulation upon NPC1 dysfunction, which causes Niemann Pick type C disease (NPC), causes increased partitioning of APP into lipid rafts leading to increased CTF/A{beta} formation in these cholesterol-rich membrane microdomains. To test this we used CHO NPC1{sup -/-} cells (NPC cells) and parental CHOwt cells. By sucrose density gradient centrifugation we observed a shift in fl-APP/CTF compartmentalization into lipid raft fractions upon cholesterol accumulation in NPC vs. wt cells. Furthermore, {gamma}-secretase inhibitor treatment significantly increased fl-APP/CTF distribution in raft fractions in NPC vs. wt cells, suggesting that upon cholesterol accumulation in NPC1-null cells increased formation of APP-CTF and its increased processing towards A{beta} occurs in lipid rafts. Our results support that cholesterol overload, such as in NPC disease, leads to increased partitioning of APP/CTF into lipid rafts resulting in increased amyloidogenic processing of APP in these cholesterol-rich membranes. This work adds to the mechanism of the cholesterol-effect on APP processing and the pathogenesis of Alzheimer's disease and supports the role of lipid rafts in these processes.

  8. Serum protein capillary electrophoresis and measurement of acute phase proteins in a captive cheetah (Acinonyx jubatus) population.

    PubMed

    Depauw, Sarah; Delanghe, Joris; Whitehouse-Tedd, Katherine; Kjelgaard-Hansen, Mads; Christensen, Michelle; Hesta, Myriam; Tugirimana, Pierrot; Budd, Jane; Dermauw, Veronique; Janssens, Geert P J

    2014-09-01

    Renal and gastrointestinal pathologies are widespread in the captive cheetah (Acinonyx jubatus) population but are often diagnosed at a late stage, because diagnostic tools are limited to the evaluation of clinical signs or general blood examination. Presently, no data are available on serum proteins and acute-phase proteins in cheetahs during health or disease, although they might be important to improve health monitoring. This study aimed to quantify serum proteins by capillary electrophoresis in 80 serum samples from captive cheetahs, categorized according to health status and disease type. Moreover, serum amyloid A concentrations were measured via a turbidimetric immunoassay validated in domestic cats, whereas haptoglobin and C-reactive protein were determined by non-species-specific functional tests. Cheetahs classified as healthy had serum protein and acute phase protein concentrations within reference ranges for healthy domestic cats. In contrast, unhealthy cheetahs had higher (P < 0.001) serum amyloid A, alpha2-globulin, and haptoglobin concentrations compared with the healthy subgroup. Moreover, serum amyloid A (P = 0.020), alpha2-globulin (P < 0.001) and haptoglobin (P = 0.001) concentrations in cheetahs suffering from chronic kidney disease were significantly greater compared to the reportedly healthy cheetahs. Our study indicates that serum proteins in the cheetah can be analyzed by routine capillary electrophoresis, whereas acute-phase proteins can be measured using available immunoassays or non-species-specific techniques, which are also likely to be applicable in other exotic felids. Moreover, results suggest that serum amyloid A and haptoglobin are important acute-phase proteins in the diseased cheetah and highlight the need to evaluate their role as early-onset markers for disease.

  9. Genetic suppression of transgenic APP rescues Hypersynchronous network activity in a mouse model of Alzeimer's disease.

    PubMed

    Born, Heather A; Kim, Ji-Yoen; Savjani, Ricky R; Das, Pritam; Dabaghian, Yuri A; Guo, Qinxi; Yoo, Jong W; Schuler, Dorothy R; Cirrito, John R; Zheng, Hui; Golde, Todd E; Noebels, Jeffrey L; Jankowsky, Joanna L

    2014-03-12

    Alzheimer's disease (AD) is associated with an elevated risk for seizures that may be fundamentally connected to cognitive dysfunction. Supporting this link, many mouse models for AD exhibit abnormal electroencephalogram (EEG) activity in addition to the expected neuropathology and cognitive deficits. Here, we used a controllable transgenic system to investigate how network changes develop and are maintained in a model characterized by amyloid β (Aβ) overproduction and progressive amyloid pathology. EEG recordings in tet-off mice overexpressing amyloid precursor protein (APP) from birth display frequent sharp wave discharges (SWDs). Unexpectedly, we found that withholding APP overexpression until adulthood substantially delayed the appearance of epileptiform activity. Together, these findings suggest that juvenile APP overexpression altered cortical development to favor synchronized firing. Regardless of the age at which EEG abnormalities appeared, the phenotype was dependent on continued APP overexpression and abated over several weeks once transgene expression was suppressed. Abnormal EEG discharges were independent of plaque load and could be extinguished without altering deposited amyloid. Selective reduction of Aβ with a γ-secretase inhibitor has no effect on the frequency of SWDs, indicating that another APP fragment or the full-length protein was likely responsible for maintaining EEG abnormalities. Moreover, transgene suppression normalized the ratio of excitatory to inhibitory innervation in the cortex, whereas secretase inhibition did not. Our results suggest that APP overexpression, and not Aβ overproduction, is responsible for EEG abnormalities in our transgenic mice and can be rescued independently of pathology.

  10. Role of human GKN1 on APP processing in gastric cancer.

    PubMed

    Di Stadio, Chiara Stella; Altieri, Filomena; Minopoli, Giuseppina; Miselli, Giuseppina; Rippa, Emilia; Arcari, Paolo

    2017-04-01

    Gastrokine 1 (GKN1) is highly expressed in gastric tissue and is secreted into the stomach but is not expressed in gastric cancer. GKN1 belongs to the BRICHOS domain family and plays a major role in maintaining gastric mucosa integrity. We previously demonstrated that a recombinant human GKN1 protein was able to interact with the amyloid precursor protein (APP) and was endowed with an anti-amyloidogenic property because it inhibited polymerization of the Aβ(1-40) peptide released from APP upon its partial hydrolysis. Here, we report that GKN1 can act as a physiological suppressor of Aβ production in gastric cancer cells. GKN1 blocked the access of γ-secretase to APP, thereby facilitating the cleavage of APP by α- and β-secretases. GKN1 directly interacted with APP C-terminal fragments, C83 and C99. In addition, it did not affect γ-secretase activity in gastric cancer cells because it did not alter Notch1 processing. GKN1-mediated inhibition of APP processing might represent a new approach for the prevention and therapy of Alzheimer's disease (AD).

  11. Clinicopathological Significance of TARBP2, APP, and ZNF395 in Breast Cancer

    PubMed Central

    Oi, Ryoko; Koizumi, Hirotaka; Maeda, Ichiro; Noguchi, Akira; Tatsunami, Shinobu; Iwatani, Tsuguo; Kawamoto, Hisanori; Tsugawa, Koichiro; Takagi, Masayuki

    2016-01-01

    The double-stranded RNA-binding protein TARBP2 has been suggested to act as an upstream regulator of breast cancer metastasis by destabilizing transcripts of the possible metastasis suppressors amyloid precursor protein (APP) and ZNF395. We examined this hypothesis by immunostaining of TARBP2, APP, and ZNF395 in 200 breast cancer specimens using tissue microarrays and analyzed the relationships between expression levels and clinicopathological parameters and prognosis. Increased TARBP2 overexpression was associated with shorter overall survival and disease-free survival, and increased but not reduced APP expression correlated with lower overall survival and disease-free survival. ZNF395 expression levels had no prognostic value, but reduced expression correlated with reduced lymph node metastasis. There was no significant relationship between TARBP2 overexpression and reduced APP and/or ZNF395 expression. Patients with tumors with higher TARBP2 or APP expression had unfavorable prognoses. Although reduced ZNF395 expression was significantly related to reduced lymph node metastasis, further studies are needed to clarify the role of TARBP2/APP/ZNF395 in breast cancer. PMID:27980417

  12. StopApp: Using the Behaviour Change Wheel to Develop an App to Increase Uptake and Attendance at NHS Stop Smoking Services.

    PubMed

    Fulton, Emily Anne; Brown, Katherine E; Kwah, Kayleigh L; Wild, Sue

    2016-06-08

    Smokers who attend NHS Stop Smoking Services (SSS) are four times more likely to stop smoking; however, uptake has been in decline. We report the development of an intervention designed to increase uptake of SSS, from a more motivated self-selected sample of smokers. In Phase 1 we collected data to explore the barriers and facilitators to people using SSS. In Phase 2, data from extant literature and Phase 1 were subject to behavioural analysis, as outlined by the Behaviour Change Wheel (BCW) framework. Relevant Behaviour Change Techniques (BCTs) were identified in order to address these, informing the content of the StopApp intervention. In Phase 3 we assessed the acceptability of the StopApp. Smokers and ex-smokers identified a number of barriers to attending SSS, including a lack of knowledge about what happens at SSS (Capability); the belief that SSS is not easy to access (Opportunity); that there would be 'scare tactics' or 'nagging'; and not knowing anyone who had been and successfully quit (Motivation). The 'StopApp' is in development and will link in with the commissioned SSS booking system. Examples of the content and functionality of the app are outlined. The next phase will involve a full trial to test effectiveness.

  13. Quantitation and localization of intracellular redox active metals by X-ray fluorescence microscopy in cortical neurons derived from APP and APLP2 knockout tissue

    SciTech Connect

    Ciccotosto, Giuseppe D.; James, Simon A.; Altissimo, Matteo; Paterson, David; Vogt, Stefan; Lai, Barry; de Jonge, Martin D.; Howard, Daryl L.; Bush, Ashley I.; Cappai, Roberto

    2014-10-01

    The amyloid precursor protein (APP) gene family includes APP and the amyloid precursor-like proteins, APLP1 and APLP2. These proteins contain metal binding sites for copper, zinc and iron and are known to have physiological roles in modulating the metal homeostasis in brain cells. Here we report the application of X-ray fluorescence microscopy (XFM) to investigate the subcellular distribution patterns of the metal ions Cu, Zn, Fe, and Ca in individual neurons derived from APP and APLP2 knockout mice brains to further define their role in metal homeostasis. These studies add to the growing body of data that the APP family of proteins are metalloproteins that have shared as well as distinct effects on metals. As we continue to delineate the cellular effects of the APP family of proteins it is important to consider how metals are involved in their actions.

  14. Quantitation and localization of intracellular redox active metals by X-ray fluorescence microscopy in cortical neurons derived from APP and APLP2 knockout tissue

    DOE PAGES

    Ciccotosto, Giuseppe D.; James, Simon A.; Altissimo, Matteo; ...

    2014-10-01

    The amyloid precursor protein (APP) gene family includes APP and the amyloid precursor-like proteins, APLP1 and APLP2. These proteins contain metal binding sites for copper, zinc and iron and are known to have physiological roles in modulating the metal homeostasis in brain cells. Here we report the application of X-ray fluorescence microscopy (XFM) to investigate the subcellular distribution patterns of the metal ions Cu, Zn, Fe, and Ca in individual neurons derived from APP and APLP2 knockout mice brains to further define their role in metal homeostasis. These studies add to the growing body of data that the APP familymore » of proteins are metalloproteins that have shared as well as distinct effects on metals. As we continue to delineate the cellular effects of the APP family of proteins it is important to consider how metals are involved in their actions.« less

  15. Overview of an Algorithm Plugin Package (APP)

    NASA Astrophysics Data System (ADS)

    Linda, M.; Tilmes, C.; Fleig, A. J.

    2004-12-01

    Science software that runs operationally is fundamentally different than software that runs on a scientist's desktop. There are complexities in hosting software for automated production that are necessary and significant. Identifying common aspects of these complexities can simplify algorithm integration. We use NASA's MODIS and OMI data production systems as examples. An Algorithm Plugin Package (APP) is science software that is combined with algorithm-unique elements that permit the algorithm to interface with, and function within, the framework of a data processing system. The framework runs algorithms operationally against large quantities of data. The extra algorithm-unique items are constrained by the design of the data processing system. APPs often include infrastructure that is vastly similar. When the common elements in APPs are identified and abstracted, the cost of APP development, testing, and maintenance will be reduced. This paper is an overview of the extra algorithm-unique pieces that are shared between MODAPS and OMIDAPS APPs. Our exploration of APP structure will help builders of other production systems identify their common elements and reduce algorithm integration costs. Our goal is to complete the development of a library of functions and a menu of implementation choices that reflect common needs of APPs. The library and menu will reduce the time and energy required for science developers to integrate algorithms into production systems.

  16. Supporting Cancer Patients in Illness Management: Usability Evaluation of a Mobile App

    PubMed Central

    Kaufman, David R; Ruland, Cornelia M

    2014-01-01

    influenced by different context-related factors, such as type of access terminal (eg, desktop computer, tablet, mobile phone) and phases of illness. Based on the observed results, we proposed design and functionality recommendations that can be used for the development of mobile apps for cancer patients to support their health management process. Conclusions Understanding and addressing users’ requirements is one of the main prerequisites for developing useful and effective technology-based health interventions. The results of this study outline different user requirements related to the design of the mobile patient support app for cancer patients. The results will be used in the iterative development of the Connect Mobile app and can also inform other developers and researchers in development, integration, and evaluation of mobile health apps and services that support cancer patients in managing their health-related issues. PMID:25119490

  17. There’s an App for That: Content Analysis of Paid Health and Fitness Apps

    PubMed Central

    Hall, P. Cougar; Hanson, Carl L; Barnes, Michael D; Giraud-Carrier, Christophe; Barrett, James

    2012-01-01

    Background The introduction of Apple’s iPhone provided a platform for developers to design third-party apps, which greatly expanded the functionality and utility of mobile devices for public health. Objective This study provides an overview of the developers’ written descriptions of health and fitness apps and appraises each app’s potential for influencing behavior change. Methods Data for this study came from a content analysis of health and fitness app descriptions available on iTunes during February 2011. The Health Education Curriculum Analysis Tool (HECAT) and the Precede-Proceed Model (PPM) were used as frameworks to guide the coding of 3336 paid apps. Results Compared to apps with a cost less than US $0.99, apps exceeding US $0.99 were more likely to be scored as intending to promote health or prevent disease (92.55%, 1925/3336 vs 83.59%, 1411/3336; P<.001), to be credible or trustworthy (91.11%, 1895/3336 vs 86.14%, 1454/3349; P<.001), and more likely to be used personally or recommended to a health care client (72.93%, 1517/2644 vs 66.77%, 1127/2644; P<.001). Apps related to healthy eating, physical activity, and personal health and wellness were more common than apps for substance abuse, mental and emotional health, violence prevention and safety, and sexual and reproductive health. Reinforcing apps were less common than predisposing and enabling apps. Only 1.86% (62/3336) of apps included all 3 factors (ie, predisposing, enabling, and reinforcing). Conclusions Development efforts could target public health behaviors for which few apps currently exist. Furthermore, practitioners should be cautious when promoting the use of apps as it appears most provide health-related information (predisposing) or make attempts at enabling behavior, with almost none including all theoretical factors recommended for behavior change. PMID:22584372

  18. Monoolein lipid phases as incorporation and enrichment materials for membrane protein crystallization.

    SciTech Connect

    Wallace, E.; Dranow, D.; Laible, P. D.; Christensen, J.; Nollert, P.

    2011-01-01

    The crystallization of membrane proteins in amphiphile-rich materials such as lipidic cubic phases is an established methodology in many structural biology laboratories. The standard procedure employed with this methodology requires the generation of a highly viscous lipidic material by mixing lipid, for instance monoolein, with a solution of the detergent solubilized membrane protein. This preparation is often carried out with specialized mixing tools that allow handling of the highly viscous materials while minimizing dead volume to save precious membrane protein sample. The processes that occur during the initial mixing of the lipid with the membrane protein are not well understood. Here we show that the formation of the lipidic phases and the incorporation of the membrane protein into such materials can be separated experimentally. Specifically, we have investigated the effect of different initial monoolein-based lipid phase states on the crystallization behavior of the colored photosynthetic reaction center from Rhodobacter sphaeroides. We find that the detergent solubilized photosynthetic reaction center spontaneously inserts into and concentrates in the lipid matrix without any mixing, and that the initial lipid material phase state is irrelevant for productive crystallization. A substantial in-situ enrichment of the membrane protein to concentration levels that are otherwise unobtainable occurs in a thin layer on the surface of the lipidic material. These results have important practical applications and hence we suggest a simplified protocol for membrane protein crystallization within amphiphile rich materials, eliminating any specialized mixing tools to prepare crystallization experiments within lipidic cubic phases. Furthermore, by virtue of sampling a membrane protein concentration gradient within a single crystallization experiment, this crystallization technique is more robust and increases the efficiency of identifying productive crystallization

  19. Nucleation of protein crystals: critical nuclei, phase behavior, and control pathways

    NASA Astrophysics Data System (ADS)

    Galkin, Oleg; Vekilov, Peter G.

    2001-11-01

    We have studied the nucleation of crystals of the model protein lysozyme using a novel technique that allows direct determinations of homogeneous nucleation rates. At constant temperature of 12.6°C we varied the thermodynamic supersaturation by changing the concentrations of protein and precipitant. We found a broken dependence of the homogeneous nucleation rate on supersaturation that is beyond the predictions of the classical nucleation theory. The nucleation theorem allows us to relate this to discrete changes of the size of the crystal nuclei with increasing supersaturation as (10 or 11)→(4 or 5)→(1 or 2). Furthermore, we observe that the existence of a second liquid phase at high protein concentrations strongly affects crystal nucleation kinetics. We show that the rate of homogeneous nucleation of lysozyme crystals passes through a maximum in the vicinity of the liquid-liquid phase boundary hidden below the liquidus (solubility) line in the phase diagram of the protein solution. We found that glycerol and polyethylene glycol (PEG), which do not specifically bind to proteins, shift this phase boundary and significantly suppress or enhance the crystal nucleation rates, although no simple correlation exists between the action of PEG on the phase diagram and the nucleation kinetics. This provides for a control mechanism which does not require changes in the protein concentration, or the acidity and ionicity of the solution. The effects of the two additives on the phase diagram strongly depend on their concentration and this provides opportunities for further tuning of nucleation rates.

  20. Gas-phase concentration, purification, and identification of whole proteins from complex mixtures.

    PubMed

    Reid, Gavin E; Shang, Hao; Hogan, Jason M; Lee, Gil U; McLuckey, Scott A

    2002-06-26

    Five proteins present in a relatively complex mixture derived from a whole cell lysate fraction of E. coli have been concentrated, purified, and dissociated in the gas phase, using a quadrupole ion trap mass spectrometer. Concentration of intact protein ions was effected using gas-phase ion/ion proton-transfer reactions in conjunction with mass-to-charge dependent ion "parking" to accumulate protein ions initially dispersed over a range of charge states into a single lower charge state. Sequential ion isolation events interspersed with additional ion parking ion/ion reaction periods were used to "charge-state purify" the protein ion of interest. Five of the most abundant protein components present in the mixture were subjected to this concentration/purification procedure and then dissociated by collisional activation of their intact multiply charged precursor ions. Four of the five proteins were subsequently identified by matching the uninterpreted product ion spectra against a partially annotated protein sequence database, coupled with a novel scoring scheme weighted for the relative abundances of the experimentally observed product ions and the frequency of fragmentations occurring at preferential cleavage sites. The identification of these proteins illustrates the potential of this "top-down" protein identification approach to reduce the reliance on condensed-phase chemistries and extensive separations for complex protein mixture analysis.

  1. Protein phase behavior and crystallization: Effect of glycerol

    NASA Astrophysics Data System (ADS)

    Sedgwick, H.; Cameron, J. E.; Poon, W. C. K.; Egelhaaf, S. U.

    2007-09-01

    Glycerol is widely used as an additive to stabilize proteins in aqueous solution. We have studied the effect of up to 40wt% glycerol on the crystallization of lysozyme from brine. As the glycerol concentration increased, progressively larger amounts of salt were needed to crystallize the protein. Like previous authors, we interpret this as evidence for glycerol changing the interaction between lysozyme molecules. We quantitatively model the interprotein interaction using a Derjaguin-Landau-Verwey-Overbeek potential. We find that the effect of glycerol can be entirely accounted for by the way it modifies the dielectric constant and refractive index of the solvent. Quantifying the interprotein interaction by the second virial coefficient, B2, we find a universal crystallization boundary for all glycerol concentrations.

  2. Protein phase behavior and crystallization: effect of glycerol.

    PubMed

    Sedgwick, H; Cameron, J E; Poon, W C K; Egelhaaf, S U

    2007-09-28

    Glycerol is widely used as an additive to stabilize proteins in aqueous solution. We have studied the effect of up to 40 wt % glycerol on the crystallization of lysozyme from brine. As the glycerol concentration increased, progressively larger amounts of salt were needed to crystallize the protein. Like previous authors, we interpret this as evidence for glycerol changing the interaction between lysozyme molecules. We quantitatively model the interprotein interaction using a Derjaguin-Landau-Verwey-Overbeek potential. We find that the effect of glycerol can be entirely accounted for by the way it modifies the dielectric constant and refractive index of the solvent. Quantifying the interprotein interaction by the second virial coefficient, B(2), we find a universal crystallization boundary for all glycerol concentrations.

  3. Ceruloplasmin: Macromolecular Assemblies with Iron-Containing Acute Phase Proteins

    PubMed Central

    Samygina, Valeriya R.; Sokolov, Alexey V.; Bourenkov, Gleb; Petoukhov, Maxim V.; Pulina, Maria O.; Zakharova, Elena T.; Vasilyev, Vadim B.; Bartunik, Hans; Svergun, Dmitri I.

    2013-01-01

    Copper-containing ferroxidase ceruloplasmin (Cp) forms binary and ternary complexes with cationic proteins lactoferrin (Lf) and myeloperoxidase (Mpo) during inflammation. We present an X-ray crystal structure of a 2Cp-Mpo complex at 4.7 Å resolution. This structure allows one to identify major protein–protein interaction areas and provides an explanation for a competitive inhibition of Mpo by Cp and for the activation of p-phenylenediamine oxidation by Mpo. Small angle X-ray scattering was employed to construct low-resolution models of the Cp-Lf complex and, for the first time, of the ternary 2Cp-2Lf-Mpo complex in solution. The SAXS-based model of Cp-Lf supports the predicted 1∶1 stoichiometry of the complex and demonstrates that both lobes of Lf contact domains 1 and 6 of Cp. The 2Cp-2Lf-Mpo SAXS model reveals the absence of interaction between Mpo and Lf in the ternary complex, so Cp can serve as a mediator of protein interactions in complex architecture. Mpo protects antioxidant properties of Cp by isolating its sensitive loop from proteases. The latter is important for incorporation of Fe3+ into Lf, which activates ferroxidase activity of Cp and precludes oxidation of Cp substrates. Our models provide the structural basis for possible regulatory role of these complexes in preventing iron-induced oxidative damage. PMID:23843990

  4. Membrane-Protein Binding Measured with Solution-Phase Plasmonic Nanocube Sensors

    PubMed Central

    Wu, Hung-Jen; Henzie, Joel; Lin, Wan-Chen; Rhodes, Christopher; Li, Zhu; Sartorel, Elodie; Thorner, Jeremy; Yang, Peidong; Groves, Jay. T.

    2013-01-01

    We describe a solution-phase sensor of lipid-protein binding based on localized surface plasmon resonance (LSPR) of silver nanocubes. When silica-coated nanocubes are mixed into a suspension of lipid vesicles, supported membranes spontaneously assemble on their surfaces. Using a standard laboratory spectrophotometer, we calibrate the LSPR peak shift due to protein binding to the membrane surface and then characterize the lipid-binding specificity of a pleckstrin-homology domain protein. PMID:23085614

  5. Immunogenic protein variations of Clostridium chauvoei cellular antigens associated with the culture growth phase.

    PubMed

    Mattar, María Aída; Cortiñas, Teresa Inés; de Guzmán, Ana María Stefanini

    2002-03-25

    The immunoprotective capacity of four Clostridium chauvoei strains at different growth stages is reported. In all the strains tested, the cells coming from the stationary phase were those with the highest immunoprotective capacity and, depending on the strain, this protective capacity diminished or even disappeared in other phases. Protein profiles were similar in all the strains and few proteins were differentially expressed during growth as shown by SDS-PAGE. For strain 17, a local strain, a clear relationship was observed between the diminution of immunogenicity and the total loss of protective capacity of sonicated cells at late stationary phase.

  6. Protein-mediated loops and phase transition in nonthermal denaturation of DNA

    NASA Astrophysics Data System (ADS)

    Petrosyan, Karen G.; Hu, Chin-Kun

    2011-01-01

    We use a statistical mechanical model to study nonthermal denaturation of DNA in the presence of protein-mediated loops. We find that looping proteins which randomly link DNA bases located at a distance along the chain could cause a first-order phase transition. We estimate the denaturation transition time near the phase transition, which can be compared with experimental data. The model describes the formation of multiple loops via dynamical (fluctuational) linking between looping proteins, which is essential in many cellular biological processes.

  7. From analogue to apps--developing an app to prepare children for medical imaging procedures.

    PubMed

    Williams, Gigi; Greene, Siobhan

    2015-01-01

    The Royal Children's Hospital (RCH) in Melbourne has launched a world-first app for children that will help reduce anxiety and the need for anesthesia during medical imaging procedures. The free, game-based app, "Okee in Medical Imaging", helps children aged from four to eight years to prepare for all medical imaging procedures--X-ray, CT, MRI, ultrasound, nuclear medicine, and fluoroscopy. The app is designed to reduce anticipatory fear of imaging procedures, while helping to ensure that children attend imaging appointments equipped with the skills required for efficient and effective scans to be performed. This paper describes how the app was developed.

  8. Spectral-domain optical coherence phase microscopy for label-free multiplexed protein microarray assay.

    PubMed

    Joo, Chulmin; Ozkumur, Emre; Unlü, M Selim; Boer, Johannes F de

    2009-10-15

    Quantitative measurement of affinities and kinetics of various biomolecular interactions such as protein-protein, protein-DNA and receptor-ligand is central to our understanding of basic molecular and cellular functions and is useful for therapeutic evaluation. Here, we describe a laser-scanning quantitative imaging method, referred to as spectral-domain optical coherence phase microscopy, as an optical platform for label-free detection of biomolecular interactions. The instrument is based on a confocal interferometric microscope that enables depth-resolved quantitative phase measurements on sensor surface with high spatial resolution and phase stability. We demonstrate picogram per square millimeter surface mass sensitivity, and show its sensing capability by presenting static and dynamic detection of multiplexed protein microarray as immobilized antigens capture their corresponding antibodies.

  9. Percolation-like phase transitions in network models of protein dynamics

    NASA Astrophysics Data System (ADS)

    Weber, Jeffrey K.; Pande, Vijay S.

    2015-06-01

    In broad terms, percolation theory describes the conditions under which clusters of nodes are fully connected in a random network. A percolation phase transition occurs when, as edges are added to a network, its largest connected cluster abruptly jumps from insignificance to complete dominance. In this article, we apply percolation theory to meticulously constructed networks of protein folding dynamics called Markov state models. As rare fluctuations are systematically repressed (or reintroduced), we observe percolation-like phase transitions in protein folding networks: whole sets of conformational states switch from nearly complete isolation to complete connectivity in a rapid fashion. We analyze the general and critical properties of these phase transitions in seven protein systems and discuss how closely dynamics on protein folding landscapes relate to percolation on random lattices.

  10. Loss of Polo ameliorates APP-induced Alzheimer’s disease-like symptoms in Drosophila

    PubMed Central

    Peng, Fei; Zhao, Yu; Huang, Xirui; Chen, Changyan; Sun, Lili; Zhuang, Luming; Xue, Lei

    2015-01-01

    The amyloid precursor protein (APP) has been implicated in the pathogenesis of Alzheimer’s disease (AD). Despite extensive studies, little is known about the regulation of APP’s functions in vivo. Here we report that expression of human APP in Drosophila, in the same temporal-spatial pattern as its homolog APPL, induced morphological defects in wings and larval NMJ, larva and adult locomotion dysfunctions, male choice disorder and lifespan shortening. To identify additional genes that modulate APP functions, we performed a genetic screen and found that loss of Polo, a key regulator of cell cycle, partially suppressed APP-induced morphological and behavioral defects in larval and adult stages. Finally, we showed that eye-specific expression of APP induced retina degeneration and cell cycle re-entry, both phenotypes were mildly ameliorated by loss of Polo. These results suggest Polo is an important in vivo regulator of the pathological functions of APP, and provide insight into the role of cell cycle re-entry in AD pathogenesis. PMID:26597721

  11. Ear2 Deletion Causes Early Memory and Learning Deficits in APP/PS1 Mice

    PubMed Central

    Kummer, Markus P.; Hammerschmidt, Thea; Martinez, Ana; Terwel, Dick; Eichele, Gregor; Witten, Anika; Figura, Stefanie; Stoll, Monika; Schwartz, Stephanie; Pape, Hans-Christian; Schultze, Joachim L.; Weinshenker, David

    2014-01-01

    To assess the consequences of locus ceruleus (LC) degeneration and subsequent noradrenaline (NA) deficiency in early Alzheimer's disease (AD), mice overexpressing mutant amyloid precursor protein and presenilin-1 (APP/PS1) were crossed with Ear2(−/−) mice that have a severe loss of LC neurons projecting to the hippocampus and neocortex. Testing spatial memory and hippocampal long-term potentiation revealed an impairment in APP/PS1 Ear2(−/−) mice, whereas APP/PS1 or Ear2(−/−) mice showed only minor changes. These deficits were associated with distinct synaptic changes including reduced expression of the NMDA 2A subunit and increased levels of NMDA receptor 2B in APP/PS1 Ear2(−/−) mice. Acute pharmacological replacement of NA by l-threo-DOPS partially restored phosphorylation of β-CaMKII and spatial memory performance in APP/PS1 Ear2(−/−) mice. These changes were not accompanied by altered APP processing or amyloid β peptide (Aβ) deposition. Thus, early LC degeneration and subsequent NA reduction may contribute to cognitive deficits via CaMKII and NMDA receptor dysfunction independent of Aβ and suggests that NA supplementation could be beneficial in treating AD. PMID:24966384

  12. A physiologic signaling role for the γ-secretase-derived intracellular fragment of APP

    PubMed Central

    Leissring, Malcolm A.; Murphy, M. Paul; Mead, Tonya R.; Akbari, Yama; Sugarman, Michael C.; Jannatipour, Mehrdad; Anliker, Brigitte; Müller, Ulrike; Saftig, Paul; De Strooper, Bart; Wolfe, Michael S.; Golde, Todd E.; LaFerla, Frank M.

    2002-01-01

    Presenilins mediate an unusual intramembranous proteolytic activity known as γ-secretase, two substrates of which are the Notch receptor (Notch) and the β-amyloid precursor protein (APP). γ-Secretase-mediated cleavage of APP, like that of Notch, yields an intracellular fragment [APP intracellular domain (AICD)] that forms a transcriptively active complex. We now demonstrate a functional role for AICD in regulating phosphoinositide-mediated calcium signaling. Genetic ablation of the presenilins or pharmacological inhibition of γ-secretase activity (and thereby AICD production) attenuated calcium signaling in a dose-dependent and reversible manner through a mechanism involving the modulation of endoplasmic reticulum calcium stores. Cells lacking APP (and hence AICD) exhibited similar calcium signaling deficits, and—notably—these disturbances could be reversed by transfection with APP constructs containing an intact AICD, but not by constructs lacking this domain. Our findings indicate that the AICD regulates phosphoinositide-mediated calcium signaling through a γ-secretase-dependent signaling pathway, suggesting that the intramembranous proteolysis of APP may play a signaling role analogous to that of Notch. PMID:11917117

  13. Optimal processing for gel electrophoresis images: Applying Monte Carlo Tree Search in GelApp.

    PubMed

    Nguyen, Phi-Vu; Ghezal, Ali; Hsueh, Ya-Chih; Boudier, Thomas; Gan, Samuel Ken-En; Lee, Hwee Kuan

    2016-08-01

    In biomedical research, gel band size estimation in electrophoresis analysis is a routine process. To facilitate and automate this process, numerous software have been released, notably the GelApp mobile app. However, the band detection accuracy is limited due to a band detection algorithm that cannot adapt to the variations in input images. To address this, we used the Monte Carlo Tree Search with Upper Confidence Bound (MCTS-UCB) method to efficiently search for optimal image processing pipelines for the band detection task, thereby improving the segmentation algorithm. Incorporating this into GelApp, we report a significant enhancement of gel band detection accuracy by 55.9 ± 2.0% for protein polyacrylamide gels, and 35.9 ± 2.5% for DNA SYBR green agarose gels. This implementation is a proof-of-concept in demonstrating MCTS-UCB as a strategy to optimize general image segmentation. The improved version of GelApp-GelApp 2.0-is freely available on both Google Play Store (for Android platform), and Apple App Store (for iOS platform).

  14. Altered protein profile in chronic myeloid leukemia chronic phase identified by a comparative proteomic study.

    PubMed

    Pizzatti, Luciana; Sá, Lílian Ayres; de Souza, Jamison Menezes; Bisch, Paulo Mascarello; Abdelhay, Eliana

    2006-05-01

    Chronic myeloid leukemia is a hematological disorder in which the Ph chromosome is a marker of the disease, detected virtually in all cases. The chimeric transcripts encode a 210-kDa chimeric protein with altered tyrosine kinase activity, responsible for the disease phenotype. In this work, we tried to identify which are the molecular changes common to chronic phase patients, those that represent the chronic phase molecular phenotype. To address this problem we analyzed through a comparative proteomic approach, several CML bone marrow cells protein profile from patients in chronic phase and healthy bone marrow donors. From these results, we identified 31 differentially expressed proteins. Among these proteins, we pointed out c-Myc binding protein 1, 53BP1, Mdm4, OSBP-related protein 3 and Mortalin as putative candidates to BCR-ABL targets in chronic phase. Moreover, we describe for the first time the cytoplasmic protein map from bone marrow cells that helped in the elucidation of the changes we were looking for.

  15. Linkage and mutational analysis of familial Alzheimer disease kindreds for the APP gene region

    SciTech Connect

    Kamino, K.; Anderson, L.; O'dahl, S.; Nemens, E.; Bird, T.D.; Schellenberg, G.D.; Wijsman, E.M.; Kukall, W.; Larson, E. ); Heston, L.L.

    1992-11-01

    A large number of familial Alzheimer disease (FAD) kindreds were examined to determine whether mutations in the amyloid precursor protein (APP) gene could be responsible for the disease. Previous studies have identified three mutations at APP codon 717 which are pathogenic for Alzheimer disease (AD). Samples from affected subjects were examined for mutations in exons 16 and 17 of the APP gene. A combination of direct sequencing and single-strand conformational polymorphism analysis was used. Sporadic AD and normal controls were also examined by the same methods. Five sequence variants were identified. One variant at APP codon 693 resulted in a Glu[yields]Gly change. This is the same codon as the hereditary cerebral hemorrhage with amyloidosis-Dutch type Glu[yields]Gln mutation. Another single-base change at APP codon 708 did not alter the amino acid encoded at this site. Two point mutations and a 6-bp deletion were identified in the intronic sequences surrounding exon 17. None of the variants could be unambigously determined to be responsible for FAD. The larger families were also analyzed by testing for linkage of FAD to a highly polymorphic short tandem repeat marker (D21S210) that is tightly linked to APP. Highly negative LOD scores were obtained for the family groups tested, and linkage was formally excluded beyond [theta] = .10 for the Volga German kindreds, [theta] = .20 for early-onset non-Volga Germans, and [theta] = .10 for late-onset families. LOD scores for linkage of FAD to markers centromeric to APP (D21S1/S11, D21S13, and D21S215) were also negative in the three family groups. These studies show that APP mutations account for AD in only a small fraction of FAD kindreds. 49 refs., 6 figs., 4 tabs.

  16. Linkage and mutational analysis of familial Alzheimer disease kindreds for the APP gene region

    PubMed Central

    Kamino, Kouzin; Orr, Harry T.; Payami, Haydeh; Wijsman, Ellen M.; Alonso, Ma. Elisa; Pulst, Stefan M.; Anderson, Leojean; O'dahl, Sheldon; Nemens, Ellen; White, June A.; Sadovnick, Adele D.; Ball, Melvyn J.; Kaye, Jeffery; Warren, Andrew; McInnis, Melvin; Antonarakis, Stylianos E.; Korenberg, Julie R.; Sharma, Vikram; Kukull, Walter; Larson, Eric; Heston, Leonard L.; Martin, George M.; Bird, Thomas D.; Schellenberg, Gerard D.

    1992-01-01

    A large number of familial Alzheimer disease (FAD) kindreds were examined to determine whether mutations in the amyloid precursor protein (APP) gene could be responsible for the disease. Previous studies have identified three mutations at APP codon 717 which are pathogenic for Alzheimer disease (AD). Samples from affected subjects were examined for mutations in exons 16 and 17 of the APP gene. A combination of direct sequencing and single-strand conformational polymorphism analysis was used. Sporadic AD and normal controls were also examined by the same methods. Five sequence variants were identified. One variant at APP codon 693 resulted in a Glu→Gly change. This is the same codon as the hereditary cerebral hemorrhage with amyloidosis–Dutch type Glu→Gln mutation. Another single-base change at APP codon 708 did not alter the amino acid encoded at this site. Two point mutations and a 6-bp deletion were identified in the intronic sequences surrounding exon 17. None of the variants could be unambiguously determined to be responsible for FAD. The larger families were also analyzed by testing for linkage of FAD to a highly polymorphic short tandem repeat marker (D21S210) that is tightly linked to APP. Highly negative LOD scores were obtained for the family groups tested, and linkage was formally excluded beyond θ = .10 for the Volga German kindreds, θ = .20 for early-onset non-Volga Germans, and θ = .10 for late-onset families. LOD scores for linkage of FAD to markers centromeric to APP (D21S1/S11, D21S13, and D21S215) were also negative in the three family groups. These studies show that APP mutations account for AD in only a small fraction of FAD kindreds. ImagesFigure 4p1009-a PMID:1415269

  17. Continuous protein purification using functionalized magnetic nanoparticles in aqueous micellar two-phase systems.

    PubMed

    Fischer, Ingo; Hsu, Chia-Chang; Gärtner, Markus; Müller, Christine; Overton, Tim W; Thomas, Owen R T; Franzreb, Matthias

    2013-08-30

    A novel technique for technical-scale continuous purification of proteins is presented. It is based on the combined use of functionalized magnetic nano-particles and an Aqueous Micellar Two-Phase System featuring the non-ionic surfactant, Eumulgin ES, which undergoes temperature induced phase separation at ∼25°C. In the first step, conducted below the transition temperature (i.e. 15°C), the magnetic sorbent particles are added into the single dispersed phase and bind the protein of interest. Next, on raising the temperature to 30°C the protein-laden magnetic particles partition strongly into the micelle-rich top phase of the micellar two-phase system that's formed. The magnetically susceptible top phase is then continuously separated from the micelle-poor phase in a flowthrough tailor-made magnetic extractor featuring a permanent magnet providing an upwardly acting magnetic force. This separation device was shown to be effective for continuous separation of a wide range of differently sized magnetic particle sorbents (i.e. from 2μm diameter to as small as 25nm) from a 10% (w/w) Eumulgin ES system; high separation efficiencies were recorded for the phase-forming surfactant (87 to >98%), and all magnetic sorbent particles tested (95-99.9%). Finally, protein purification by continuous magnetic extraction was demonstrated at 15L scale for the recovery of an antibody fragment, A33 Fab', from a crude extract of Escherichia coli periplasm. Nearly 70% of the A33 Fab' initially present in the extract at 15.6% of the total protein content was recovered in a 2-fold concentrated and highly purified (>98%) state. Further, the amounts of magnetic sorbent and phase-forming surfactant lost in the process were very small; thus recycling of both components into subsequent rounds of continuous magnetic extraction is highly feasible.

  18. Effects of metal ion adduction on the gas-phase conformations of protein ions.

    PubMed

    Flick, Tawnya G; Merenbloom, Samuel I; Williams, Evan R

    2013-11-01

    Changes in protein ion conformation as a result of nonspecific adduction of metal ions to the protein during electrospray ionization (ESI) from aqueous solutions were investigated using traveling wave ion mobility spectrometry (TWIMS). For all proteins examined, protein cations (and in most cases anions) with nonspecific metal ion adducts are more compact than the fully protonated (or deprotonated) ions with the same charge state. Compaction of protein cations upon nonspecific metal ion binding is most significant for intermediate charge state ions, and there is a greater reduction in collisional cross section with increasing number of metal ion adducts and increasing ion valency, consistent with an electrostatic interaction between the ions and the protein. Protein cations with the greatest number of adducted metal ions are no more compact than the lowest protonated ions formed from aqueous solutions. These results show that smaller collisional cross sections for metal-attached protein ions are not a good indicator of a specific metal-protein interaction in solution because nonspecific metal ion adduction also results in smaller gaseous protein cation cross sections. In contrast, the collisional cross section of α-lactalbumin, which specifically binds one Ca(2+), is larger for the holo-form compared with the apo-form, in agreement with solution-phase measurements. Because compaction of protein cations occurs when metal ion adduction is nonspecific, elongation of a protein cation may be a more reliable indicator that a specific metal ion-protein interaction occurs in solution.

  19. Treadmill exercise enhances synaptic plasticity, but does not alter β-amyloid deposition in hippocampi of aged APP/PS1 transgenic mice.

    PubMed

    Zhao, G; Liu, H L; Zhang, H; Tong, X J

    2015-07-09

    Several studies reveal that the beneficial effects of exercise interventions are dependent on the progression of Alzheimer's disease (AD). We have previously shown that long-term treadmill exercise begun before the onset of β-amyloid (Aβ) pathology prevents the deficits of cognition and long-term potentiation (LTP) in amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic mice (8 months of age) paralleled by the reduction of soluble Aβ levels and Aβ deposition in the hippocampus. In the present study, treadmill exercise was initiated at a developed Aβ deposition stage in order to further investigate whether or not treadmill exercise in this phase can delay the progression of AD in aged APP/PS1 mice (17 months of age). Our results show that 5-month treadmill exercise ameliorates the impairment of spatial learning and memory with age paralleled by synaptic plasticity enhancement in aged APP/PS1 mice. In addition, exercise-induced enhancement of synaptic plasticity was accompanied by a significant reduction of soluble Aβ levels rather than Aβ plaque deposition. Therefore, the investigation demonstrates that long-term treadmill exercise has beneficial effects on cognition and synaptic plasticity even when the brain has developed Aβ deposition, and changes in soluble Aβ levels rather than Aβ plaque deposition may contribute to exercise-induced benefits.

  20. The Top Chinese Mobile Health Apps: A Systematic Investigation

    PubMed Central

    Hsu, Jeffrey; Liu, Di; Yu, Ya Min; Zhao, Hui Tong; Chen, Zhi Rou; Li, Jiao

    2016-01-01

    Background China’s mHealth market is on track to become a global leader by industry size. The Chinese mobile app market and health care system have peculiarities that distinguish them from other app markets. To date, Chinese mHealth apps have not been systematically investigated. Objective The objective of this study was to provide an overview of Chinese mHealth apps as of December 2015. Methods We identified and investigated the most downloaded apps from the iOS and Android platforms. For each app, we analyzed and recorded its main service offered, mHealth initiative, disease and specialty focus, app cost, target user, Web app availability, and emphasis on information security. Standard descriptive statistics were used. Results A total of 234 apps met the inclusion criteria and were investigated. The apps targeting nonhealth care professionals focused on providing telemedicine and appointment-making services. The apps targeting health care professionals focused on education and peer reviewed articles. The most common disease-specific apps focused primarily on diabetes, hypertension, and hepatitis management. Most apps were free and available on both iOS and Android platforms. Conclusions The primary mHealth initiatives targeted by the apps reflect Chinese patients’ demand for access to medical care. Disease-specific apps are also representative of disease prevalence in China. Government press releases suggest that new policies on the horizon may shift the industry. PMID:27573724

  1. LRP-mediated clearance of Abeta is inhibited by KPI-containing isoforms of APP.

    PubMed

    Moir, Robert D; Tanzi, Rudolph E

    2005-04-01

    The pathogenesis of Alzheimer's disease (AD) involves the abnormal accumulation and deposition of beta-amyloid in cerebral blood vessels and in the brain parenchyma. Critical in modulating beta-amyloid deposition in brain is the flux of Abeta across the blood brain barrier. The low-density lipoprotein receptor-related protein (LRP), is a large endocytic receptor that mediates the efflux of Abeta out of brain and into the periphery. The first step in the LRP-mediated clearance of Abeta involves the formation of a complex between Abeta and the LRP ligands apolipoprotein E (apoE) or alpha(2)-macroglobulin (alpha(2)M). The Abeta/chaperone complexes then bind to LRP via binding sites on apoE or alpha(2)M. The efflux of Abeta/chaperone complexes out of the neuropil and into the periphery may be attenuated by LRP-ligands that compete with apoE or alpha(2)M for LRP binding. LRP is also the cell surface receptor for Kunitz Protease Inhibitor (KPI) containing isoforms of Abeta's parent protein, the amyloid protein precursor (APP). Protein and mRNA levels of KPI-containing APP isoforms (APP-KPI) are elevated in AD brain and are associated with increased Abeta production. In this study we show that soluble non-amyloidogenic APP-KPI can also inhibit the uptake of Abeta/alpha(2)M in a cell culture model of LRP mediated Abeta clearance. Clearance of Abeta/apoE complexes was not inhibited by APP-KPI. Our findings are consistent with studies showing that apoE and alpha(2)M have discrete binding sites on LRP. Most significantly, our data suggests that the elevated levels of APP-KPI in AD brain may attenuate the clearance of Abeta, the proteins own amyloidogenic catabolic product.

  2. Automated de novo phasing and model building of coiled-coil proteins.

    PubMed

    Rämisch, Sebastian; Lizatović, Robert; André, Ingemar

    2015-03-01

    Models generated by de novo structure prediction can be very useful starting points for molecular replacement for systems where suitable structural homologues cannot be readily identified. Protein-protein complexes and de novo-designed proteins are examples of systems that can be challenging to phase. In this study, the potential of de novo models of protein complexes for use as starting points for molecular replacement is investigated. The approach is demonstrated using homomeric coiled-coil proteins, which are excellent model systems for oligomeric systems. Despite the stereotypical fold of coiled coils, initial phase estimation can be difficult and many structures have to be solved with experimental phasing. A method was developed for automatic structure determination of homomeric coiled coils from X-ray diffraction data. In a benchmark set of 24 coiled coils, ranging from dimers to pentamers with resolutions down to 2.5 Å, 22 systems were automatically solved, 11 of which had previously been solved by experimental phasing. The generated models contained 71-103% of the residues present in the deposited structures, had the correct sequence and had free R values that deviated on average by 0.01 from those of the respective reference structures. The electron-density maps were of sufficient quality that only minor manual editing was necessary to produce final structures. The method, named CCsolve, combines methods for de novo structure prediction, initial phase estimation and automated model building into one pipeline. CCsolve is robust against errors in the initial models and can readily be modified to make use of alternative crystallographic software. The results demonstrate the feasibility of de novo phasing of protein-protein complexes, an approach that could also be employed for other small systems beyond coiled coils.

  3. Finding a Depression App: A Review and Content Analysis of the Depression App Marketplace

    PubMed Central

    Shen, Nelson; Levitan, Michael-Jane; Johnson, Andrew; Bender, Jacqueline Lorene; Hamilton-Page, Michelle; Jadad, Alejandro (Alex) R

    2015-01-01

    Background Depression is highly prevalent and causes considerable suffering and disease burden despite the existence of wide-ranging treatment options. Mobile phone apps offer the potential to help close this treatment gap by confronting key barriers to accessing support for depression. Objectives Our goal was to identify and characterize the different types of mobile phone depression apps available in the marketplace. Methods A search for depression apps was conducted on the app stores of the five major mobile phone platforms: Android, iPhone, BlackBerry, Nokia, and Windows. Apps were included if they focused on depression and were available to people who self-identify as having depression. Data were extracted from the app descriptions found in the app stores. Results Of the 1054 apps identified by the search strategy, nearly one-quarter (23.0%, 243/1054) unique depression apps met the inclusion criteria. Over one-quarter (27.7%, 210/758) of the excluded apps failed to mention depression in the title or description. Two-thirds of the apps had as their main purpose providing therapeutic treatment (33.7%, 82/243) or psychoeducation (32.1%, 78/243). The other main purpose categories were medical assessment (16.9%, 41/243), symptom management (8.2%, 20/243), and supportive resources (1.6%, 4/243). A majority of the apps failed to sufficiently describe their organizational affiliation (65.0%, 158/243) and content source (61.7%, 150/243). There was a significant relationship (χ 2 5=50.5, P<.001) between the main purpose of the app and the reporting of content source, with most medical assessment apps reporting their content source (80.5%, 33/41). A fifth of the apps featured an e-book (20.6%, 50/243), audio therapy (16.9%, 41/243), or screening (16.9%, 41/243) function. Most apps had a dynamic user interface (72.4%, 176/243) and used text as the main type of media (51.9%, 126/243), and over a third (14.4%, 35/243) incorporated more than one form of media. Conclusion

  4. PLASMA PROTEIN ELECTROPHORESIS AND SELECT ACUTE PHASE PROTEINS IN HEALTHY BONNETHEAD SHARKS (SPHYRNA TIBURO) UNDER MANAGED CARE.

    PubMed

    Hyatt, Michael W; Field, Cara L; Clauss, Tonya M; Arheart, Kristopher L; Cray, Carolyn

    2016-12-01

    Preventative health care of elasmobranchs is an important but understudied field of aquatic veterinary medicine. Evaluation of inflammation through the acute phase response is a valuable tool in health assessments. To better assess the health of bonnethead sharks ( Sphyrna tiburo ) under managed care, normal reference intervals of protein electrophoresis (EPH) and the acute phase proteins, C-reactive protein (CRP) and haptoglobin (HP), were established. Blood was collected from wild caught, captive raised bonnethead sharks housed at public aquaria. Lithium heparinized plasma was either submitted fresh or stored at -80°C prior to submission. Electrophoresis identified protein fractions with migration characteristics similar to other animals with albumin, α-1 globulin, α-2 globulin, β globulin, and γ globulin. These fractions were classified as fractions 1-5 as fractional contents are unknown in this species. Commercial reagents for CRP and HP were validated for use in bonnethead sharks. Reference intervals were established using the robust method recommended by the American Society for Veterinary Clinical Pathology for the calculation of 90% reference intervals. Once established, the diagnostic and clinical applicability of these reference intervals was used to assess blood from individuals with known infectious diseases that resulted in systemic inflammation and eventual death. Unhealthy bonnethead sharks had significantly decreased fraction 2, fraction 3, and fraction 3:4 ratio and significantly increased fraction 5, CRP, and HP. These findings advance our understanding of elasmobranch acute phase inflammatory response and health and aid clinicians in the diagnosis of inflammatory disease in bonnethead sharks.

  5. Photo dynamics of BLUF domain mutant H44R of AppA from Rhodobacter sphaeroides

    NASA Astrophysics Data System (ADS)

    Zirak, P.; Penzkofer, A.; Hegemann, P.; Mathes, T.

    2007-05-01

    The photo-cycle dynamics of the H44R mutant of the BLUF domain of the transcriptional anti-repressor protein AppA (AppA-H44R) from the non-sulfur anoxyphototropic purple bacterium Rhodobacter sphaeroides is studied in order to gain information on the involvement of His44 in the photo-cyclic mechanism of the AppA BLUF domain and to add information to the involved processes. The amino acid residue histidine at position 44 is replaced by arginine. A 12 nm red-shifted signalling state is formed upon blue-light excitation, while in wild-type AppA (AppA-wt) the red-shift is 16 nm. The recovery to the receptor dark state is approximately a factor of 2.5 faster ( τrec ≈ 6.5 min) than the recovery of the wild-type counterpart. Extended light exposure of the mutant causes photo-degradation of flavin (mainly free flavin conversion to lumichrome and re-equilibration between free and non-covalently bound flavin) and protein aggregation (showing up as light scattering). No photo-degradation was observed for AppA-wt. The quantum efficiency of signalling-state formation determined by intensity dependent absorption measurements is found to be ϕs ≈ 0.3 (for AppA-wt: ϕs ≈ 0.24). A two-component single-exponential fluorescence relaxation was observed, which is interpreted as fast fluorescence quenching to an equilibrium value by photo-induced electron transfer followed by slower fluorescence decay due to charge recombination. Based on the experimental findings, an extended photo-cycle model for BLUF domains is proposed.

  6. Cerebrospinal Fluid Aβ42 Levels and APP Processing Pathway Genes in Parkinson’s Disease

    PubMed Central

    Bekris, L.M.; Tsuang, D.W.; Peskind, E.R.; Yu, C.E.; Montine, T.J.; Zhang, J.; Zabetian, C.P.; Leverenz, J.B.

    2015-01-01

    Background Of recent interest is the finding that certain CSF biomarkers traditionally linked to Alzheimer’s disease (AD), specifically amyloid beta protein (Aβ), are abnormal in PD CSF. The aim of this exploratory investigation was to determine if genetic variation within the amyloid precursor protein (APP) processing pathway genes, correlate with cerebrospinal fluid (CSF) Aβ42 levels in Parkinson’s disease (PD). Method PD (n=86) and control (n=161) DNA were genotyped for 19 regulatory region tagging single nucleotide polymorphisms (SNPs) within nine genes (APP, ADAM10, BACE1, BACE2, PSEN1, PSEN2, PEN2, NCSTN and APH1B) involved in the cleavage of APP. SNP genotypes were tested for their association with CSF biomarkers and PD risk while adjusting for age, gender, and APOE ε4 status. Results Significant correlation with CSF Aβ42 levels in PD was observed for two SNPs, (APP rs466448 and APH1B rs2068143). Conversely, significant correlation with CSF Aβ42 levels in controls was observed for three SNPs (APP rs214484 and rs2040273 and PSEN1 rs362344). Conclusion The results of this exploratory investigation suggest that an APP SNP and an APH1B SNP are marginally associated with PD CSF Aβ42 levels in APOE ε4 non-carriers. Further hypotheses generated include that decreased CSF Aβ42 levels are in part driven by genetic variation in APP processing genes. Additional investigation into the relationship between these findings and clinical characteristics of PD, including cognitive impairment, compared to other neurodegenerative diseases, such as AD, are warranted. PMID:25808939

  7. Cloning and Expression of Phytase appA Gene from Shigella sp. CD2 in Pichia pastoris and Comparison of Properties with Recombinant Enzyme Expressed in E. coli.

    PubMed

    Pal Roy, Moushree; Mazumdar, Deepika; Dutta, Subhabrata; Saha, Shyama Prasad; Ghosh, Shilpi

    2016-01-01

    The phytase gene appAS was isolated from Shigella sp. CD2 genomic library. The 3.8 kb DNA fragment contained 1299 bp open reading frame encoding 432 amino acid protein (AppAS) with 22 amino acid signal peptide at N-terminal and three sites of N-glycosylation. AppAS contained the active site RHGXRXP and HDTN sequence motifs, which are conserved among histidine acid phosphatases. It showed maximum identity with phytase AppA of Escherichia coli and Citrobacter braakii. The appAS was expressed in Pichia pastoris and E. coli to produce recombinant phytase rAppAP and rAppAE, respectively. Purified glycosylated rAppAP and nonglycosylated rAppAE had specific activity of 967 and 2982 U mg(-1), respectively. Both had pH optima of 5.5 and temperature optima of 60°C. Compared with rAppAE, rAppAP was 13 and 17% less active at pH 3.5 and 7.5 and 11 and 18% less active at temperature 37 and 50°C, respectively; however, it was more active at higher incubation temperatures. Thermotolerance of rAppAP was 33% greater at 60°C and 24% greater at 70°C, when compared with rAppAE. Both the recombinant enzymes showed high specificity to phytate and resistance to trypsin. To our knowledge, this is the first report on cloning and expression of phytase from Shigella sp.

  8. Cloning and Expression of Phytase appA Gene from Shigella sp. CD2 in Pichia pastoris and Comparison of Properties with Recombinant Enzyme Expressed in E. coli

    PubMed Central

    Pal Roy, Moushree; Mazumdar, Deepika; Dutta, Subhabrata; Saha, Shyama Prasad; Ghosh, Shilpi

    2016-01-01

    The phytase gene appAS was isolated from Shigella sp. CD2 genomic library. The 3.8 kb DNA fragment contained 1299 bp open reading frame encoding 432 amino acid protein (AppAS) with 22 amino acid signal peptide at N-terminal and three sites of N-glycosylation. AppAS contained the active site RHGXRXP and HDTN sequence motifs, which are conserved among histidine acid phosphatases. It showed maximum identity with phytase AppA of Escherichia coli and Citrobacter braakii. The appAS was expressed in Pichia pastoris and E. coli to produce recombinant phytase rAppAP and rAppAE, respectively. Purified glycosylated rAppAP and nonglycosylated rAppAE had specific activity of 967 and 2982 U mg-1, respectively. Both had pH optima of 5.5 and temperature optima of 60°C. Compared with rAppAE, rAppAP was 13 and 17% less active at pH 3.5 and 7.5 and 11 and 18% less active at temperature 37 and 50°C, respectively; however, it was more active at higher incubation temperatures. Thermotolerance of rAppAP was 33% greater at 60°C and 24% greater at 70°C, when compared with rAppAE. Both the recombinant enzymes showed high specificity to phytate and resistance to trypsin. To our knowledge, this is the first report on cloning and expression of phytase from Shigella sp. PMID:26808559

  9. Planet App: Kids' Book Apps Are Everywhere. But Are They Any Good?

    ERIC Educational Resources Information Center

    Bird, Elizabeth

    2011-01-01

    A proper picture book app lets a parent and child read, listen to, or explore a book in a fun and interactive manner. Typical options offered in these apps include turning off the sound (so that a parent or child can read on their own), changing from one language to another, and small interactive features, such as making the characters move. To…

  10. Surface induced dissociation: dissecting noncovalent protein complexes in the gas phase.

    PubMed

    Zhou, Mowei; Wysocki, Vicki H

    2014-04-15

    The quaternary structures of proteins are both important and of interest to chemists, because many proteins exist as complexes in vivo, and probing these structures allows us to better understand their biological functions. Conventional structural biology methods such as X-ray crystallography and nuclear magnetic resonance provide high-resolution information on the structures of protein complexes and are the gold standards in the field. However, other emerging biophysical methods that only provide low-resolution data (e.g. stoichiometry and subunit connectivity) on the structures of the protein complexes are also becoming more important to scientists. Mass spectrometry is one of these approaches that provide lower than atomic structural resolution, but the approach is higher throughput and provides not only better mass information than other techniques but also stoichiometry and topology. Fragile noncovalent interactions within the protein complexes can be preserved in the gas phase of MS under gentle ionization and transfer conditions. Scientists can measure the masses of the complexes with high confidence to reveal the stoichiometry and composition of the proteins. What makes mass spectrometry an even more powerful method is that researchers can further isolate the protein complexes and activate them in the gas phase to release subunits for more structural information. The caveat is that, upon gas-phase activation, the released subunits need to faithfully reflect the native topology so that useful information on the proteins can be extracted from mass spectrometry experiments. Unfortunately, many proteins tend to favor unfolding upon collision with neutral gas (the most common activation method in mass spectrometers). Therefore, this typically results in limited insights on the quaternary structure of the precursor without further manipulation of other experimental factors. Scientists have observed, however, that valuable structural information can be obtained

  11. High resolution ion mobility measurements for gas phase proteins: correlation between solution phase and gas phase conformations

    NASA Astrophysics Data System (ADS)

    Hudgins, Robert R.; Woenckhaus, Jürgen; Jarrold, Martin F.

    1997-11-01

    Our high resolution ion mobility apparatus has been modified by attaching an electrospray source to perform measurements for biological molecules. While the greater resolving power permits the resolution of more conformations for BPTI and cytochrome c, the resolved features are generally much broader than expected for a single rigid conformation. A major advantage of the new experimental configuration is the much gentler introduction of ions into the drift tube, so that the observed gas phase conformations appear to more closely reflect those present in solution. For example, it is possible to distinguish between the native state of cytochrome c and the methanol-denatured form on the basis of the ion mobility measurements; the mass spectra alone are not sensitive enough to detect this change. Thus this approach may provide a quick and sensitive tool for probing the solution phase conformations of biological molecules.

  12. Water Mediated Interactions and the Protein Folding Phase Diagram in the Temperature-Pressure Plane.

    PubMed

    Sirovetz, Brian J; Schafer, Nicholas P; Wolynes, Peter G

    2015-08-27

    The temperature-pressure behavior of two proteins, ubiquitin and λ-repressor, is explored using a realistically coarse-grained physicochemical model, the associative memory, water mediated, structure and energy model (AWSEM). The phase diagram across the temperature-pressure plane is obtained by perturbing the water mediated interactions in the Hamiltonian systematically. The phase diagrams calculated with direct simulations along with an extended bridge sampling estimator show the main features found experimentally, including both cold- and pressure-denaturation. The denatured ensembles in different parts of the phase diagram are characterized and found to be structurally distinct. The protein energy landscape is found to be funneled throughout the phase diagram, but modest changes in the entropy and free energy of the water are found to drive both cold and pressure induced denaturation.

  13. Mobile App Rating Scale: A New Tool for Assessing the Quality of Health Mobile Apps

    PubMed Central

    Kavanagh, David J; Zelenko, Oksana; Tjondronegoro, Dian; Mani, Madhavan

    2015-01-01

    Background The use of mobile apps for health and well being promotion has grown exponentially in recent years. Yet, there is currently no app-quality assessment tool beyond “star”-ratings. Objective The objective of this study was to develop a reliable, multidimensional measure for trialling, classifying, and rating the quality of mobile health apps. Methods A literature search was conducted to identify articles containing explicit Web or app quality rating criteria published between January 2000 and January 2013. Existing criteria for the assessment of app quality were categorized by an expert panel to develop the new Mobile App Rating Scale (MARS) subscales, items, descriptors, and anchors. There were sixty well being apps that were randomly selected using an iTunes search for MARS rating. There were ten that were used to pilot the rating procedure, and the remaining 50 provided data on interrater reliability. Results There were 372 explicit criteria for assessing Web or app quality that were extracted from 25 published papers, conference proceedings, and Internet resources. There were five broad categories of criteria that were identified including four objective quality scales: engagement, functionality, aesthetics, and information quality; and one subjective quality scale; which were refined into the 23-item MARS. The MARS demonstrated excellent internal consistency (alpha = .90) and interrater reliability intraclass correlation coefficient (ICC = .79). Conclusions The MARS is a simple, objective, and reliable tool for classifying and assessing the quality of mobile health apps. It can also be used to provide a checklist for the design and development of new high quality health apps. PMID:25760773

  14. Smartphone app use among medical providers in ACGME training programs.

    PubMed

    Franko, Orrin I; Tirrell, Timothy F

    2012-10-01

    The past decade has witnessed the advent of the smartphone, a device armed with computing power, mobility and downloadable "apps," that has become commonplace within the medical field as both a personal and professional tool. The popularity of medically-related apps suggests that physicians use mobile technology to assist with clinical decision making, yet usage patterns have never been quantified. A digital survey examining smartphone and associated app usage was administered via email to all ACGME training programs. Data regarding respondent specialty, level of training, use of smartphones, use of smartphone apps, desired apps, and commonly used apps were collected and analyzed. Greater than 85% of respondents used a smartphone, of which the iPhone was the most popular (56%). Over half of the respondents reported using apps in their clinical practice; the most commonly used app types were drug guides (79%), medical calculators (18%), coding and billing apps (4%) and pregnancy wheels (4%). The most frequently requested app types were textbook/reference materials (average response: 55%), classification/treatment algorithms (46%) and general medical knowledge (43%). The clinical use of smartphones and apps will likely continue to increase, and we have demonstrated an absence of high-quality and popular apps despite a strong desire among physicians and trainees. This information should be used to guide the development of future healthcare delivery systems; expanded app functionality is almost certain but reliability and ease of use will likely remain major factors in determining the successful integration of apps into clinical practice.

  15. Commercially Available Mobile Phone Headache Diary Apps: A Systematic Review

    PubMed Central

    Huguet, Anna; McGrath, Patrick J; Stinson, Jennifer N; Wheaton, Mike

    2014-01-01

    Background Headache diaries are often used by headache sufferers to self-monitor headaches. With advances in mobile technology, mobile electronic diary apps are becoming increasingly common. Objective This review aims to identify and evaluate all commercially available mobile headache diary apps for the two most popular mobile phone platforms, iOS and Android. Methods The authors developed a priori a set of 7 criteria that define an ideal headache diary app intended to help headache sufferers better understand and manage their headaches, while providing relevant data to health professionals. The app criteria were intended as minimum requirements for an acceptable headache diary app that could be prescribed by health care professionals. Each app was evaluated and scored against each criterion. Results Of the 38 apps identified, none of the apps met all 7 app criteria. The 3 highest scoring apps, meeting 5 of the app criteria, were iHeadache (developed by Better QOL), ecoHeadache (developed by ecoTouchMedia), and Headache Diary Pro (developed by Froggyware). Only 18% of the apps were created with scientific or clinical headache expertise and none of the apps reported on psychometric properties. Conclusions Despite the growing market and demand, there is a concerning lack of scientific expertise and evidence base associated with headache diary apps. PMID:25138438

  16. Early downregulation of acute phase proteins after doxorubicin exposition in patients with breast cancer.

    PubMed

    Panis, Carolina; Pizzatti, Luciana; Bufalo, Aedra Carla; Herrera, Ana Cristina; Victorino, Vanessa Jacob; Cecchini, Rubens; Abdelhay, Eliana

    2016-03-01

    Chemotherapy remains the first-choice option for adjuvant therapy in breast cancer. Here, we investigated the impact of the first chemotherapic cycle of doxorubicin on the plasmatic-proteomic profiling of women diagnosed with breast cancer (n = 87). Blood samples were obtained from the same patient before and after doxorubicin infusion (1 h, 60 mg/m(2)) and processed for label-free LC-MS proteomic screening. A total of 80 proteins were downregulated after chemotherapy. In silico analysis revealed that the main biological process enrolled was inflammation and canonical pathways involving acute phase proteins. TNF-α, IL-1β, IL-12, TGF-β1, clusterin, and gelsolin were chosen as relevant for further validation. All selected targets presented reduced plasmatic levels after treatment. Our results indicate that doxorubicin downregulated acute phase proteins immediately after its infusion. Since such proteins are cancer promoting, its downregulation could support the effectiveness of doxorubicin along treatment.

  17. Arginine methylation in yeast proteins during stationary-phase growth and heat shock.

    PubMed

    Lakowski, Ted M; Pak, Magnolia L; Szeitz, András; Thomas, Dylan; Vhuiyan, Mynol I; Clement, Bernd; Frankel, Adam

    2015-12-01

    Arginine methyltransferases (RMTs) catalyze the methylation of arginine residues on proteins. We examined the effects of log-phase growth, stationary-phase growth, and heat shock on the formation of methylarginines on yeast proteins to determine if the conditions favor a particular type of methylation. Utilizing linear ion trap mass spectrometry, we identify methylarginines in wild-type and RMT deletion yeast strains using secondary product ion scans (MS(3)), and quantify the methylarginines using multiple reaction monitoring (MRM). Employing MS(3) and isotopic incorporation, we demonstrate for the first time that Nη1, Nη2-dimethylarginine (sDMA) is present on yeast proteins, and make a detailed structural determination of the fragment ions from the spectra. Nη-monomethylarginine (ηMMA), Nδ-monomethylarginine (δMMA), Nη1, Nη1-dimethylarginine (aDMA), and sDMA were detected in RMT deletion yeast using MS(3) and MRM with and without isotopic incorporation, suggesting that additional RMT enzymes remain to be discovered in yeast. The concentrations of ηMMA and δMMA decreased by half during heat shock and stationary phase compared to log-phase growth of wild-type yeast, whereas sDMA increased by as much as sevenfold and aDMA decreased by 11-fold. Therefore, upon entering stressful conditions like heat shock or stationary-phase growth, there is a net increase in sDMA and decreases in aDMA, ηMMA, and δMMA on yeast proteins.

  18. Beebook: light field mapping app

    NASA Astrophysics Data System (ADS)

    De Donatis, Mauro; Di Pietro, Gianfranco; Rinnone, Fabio

    2014-05-01

    In the last decade the mobile systems for field digital mapping were developed (see Wikipedia for "Digital geologic mapping"), also against many skeptic traditional geologists. Until now, hardware was often heavy (tablet PC) and software sometime difficult also for expert GIS users. At present, the advent of light tablet and applications makes things easier, but we are far to find a whole solution for a complex survey like the geological one where you have to manage complexities such information, hypothesis, data, interpretation. Beebook is a new app for Android devices, has been developed for fast ad easy mapping work in the field trying to try to solve this problem. The main features are: • off-line raster management, GeoTIFF ed other raster format using; • on-line map visualisation (Google Maps, OSM, WMS, WFS); • SR management and conversion using PROJ.4; • vector file mash-up (KML and SQLite format); • editing of vector data on the map (lines, points, polygons); • augmented reality using "Mixare" platform; • export of vector data in KML, CSV, SQLite (Spatialite) format; • note: GPS or manual point inserting linked to other application files (pictures, spreadsheet, etc.); • form: creation, edition and filling of customized form; • GPS: status control, tracker and positioning on map; • sharing: synchronization and sharing of data, forms, positioning and other information can be done among users. The input methods are different from digital keyboard to fingers touch, from voice recording to stylus. In particular the most efficient way of inserting information is the stylus (or pen): field geologists are familiar with annotation and sketches. Therefore we suggest the use of devices with stylus. The main point is that Beebook is the first "transparent" mobile GIS for tablet and smartphone deriving from previous experience as traditional mapping and different previous digital mapping software ideation and development (MapIT, BeeGIS, Geopaparazzi

  19. Roles of STAT3 in Protein Secretion Pathways during the Acute-Phase Response

    PubMed Central

    Ahyi, Ayele-Nati N.; Quinton, Lee J.; Jones, Matthew R.; Ferrari, Joseph D.; Pepper-Cunningham, Zachary A.; Mella, Juan R.; Remick, Daniel G.

    2013-01-01

    The acute-phase response is characteristic of perhaps all infections, including bacterial pneumonia. In conjunction with the acute-phase response, additional biological pathways are induced in the liver and are dependent on the transcription factors STAT3 and NF-κB, but these responses are poorly understood. Here, we demonstrate that pneumococcal pneumonia and other severe infections increase expression of multiple components of the cellular secretory machinery in the mouse liver, including the endoplasmic reticulum (ER) translocon complex, which mediates protein translation into the ER, and the coat protein complexes (COPI and COPII), which mediate vesicular transport of proteins to and from the ER. Hepatocyte-specific mutation of STAT3 prevented the induction of these secretory pathways during pneumonia, with similar results observed following pharmacological activation of ER stress by using tunicamycin. These findings implicate STAT3 in the unfolded protein response and suggest that STAT3-dependent optimization of secretion may apply broadly. Pneumonia also stimulated the binding of phosphorylated STAT3 to promoter regions of secretion-related genes in the liver, supporting a direct role for STAT3 in their transcription. Altogether, these results identify a novel function of STAT3 during the acute-phase response, namely, the induction of secretory machinery in hepatocytes. This may facilitate the processing and delivery of newly synthesized loads of acute-phase proteins, enhancing innate immunity and preventing liver injury during infection. PMID:23460517

  20. The 'sticky business' of cleaning gas-phase membrane proteins: a detergent oriented perspective.

    PubMed

    Borysik, Antoni J; Robinson, Carol V

    2012-11-14

    In recent years the properties of gas-phase detergent clusters have come under close scrutiny due in part to their participation in the analysis of intact membrane protein complexes by mass spectrometry. The detergent molecules that cover the protein complex are removed in the gas-phase by thermally agitating the ions by collision-induced dissociation. This process however, is not readily controlled and can frequently result in the disruption of protein structure. Improved methods of releasing proteins from detergent clusters are clearly required. To facilitate this the structural properties of detergent clusters along with the mechanistic details of their dissociation need to be understood. Pivotal to understanding the properties of gas-phase detergent clusters is the technique of ion mobility mass spectrometry. This technique can be used to assign polydisperse detergent clusters and provide information about their geometries and packing densities. In this article we consider the shapes of detergent clusters and show that these clusters possess geometries that are inconsistent with those in solution. We analyse the distributions of clusters in detail using tandem mass spectrometry and suggest that the mean charge of clusters formed from certain detergents is governed by electrostatic repulsion. We discuss the dissociation of detergent clusters and propose that detergent evaporation it a key process in the protection of protein complexes during high energy collisions in the gas-phase.

  1. Osmotic Virial Coefficients as Access to the Protein Partitioning in Aqueous Two-Phase Systems.

    PubMed

    Kress, Christian; Brandenbusch, Christoph

    2015-11-01

    A promising alternative to state of the art chromatographic separations of therapeutic proteins is the extraction of the target protein using an aqueous two-phase system (ATPS). The use of an additional salt working as a displacement agent can influence the protein partitioning behavior in ATPS and thus enable a selective purification of the target protein. The selection of a suitable ATPS for protein extraction requires information concerning the protein-protein interactions (second osmotic virial coefficient B22 ) as well as the interactions between protein and solute (displacement agent and phase-forming components) (cross virial coefficient B23 ). In this work, the partitioning behavior and the precipitation affinity of immunoglobulin G (IgG) is considered within a polyethylene glycol (PEG)-phosphate ATPS. The influence on IgG partitioning upon addition of NaCl and (NH4)2 SO4 was investigated. In order to access the IgG precipitation affinity and the IgG partitioning behavior, the B22 and B23 values were determined for several combinations of solute [PEG, phosphate buffer, NaCl, and (NH4)2 SO4 ] and IgG based on static light scattering measurements. A qualitative estimation of the IgG precipitation affinity and the suitability of a solute as potential displacement agent within the PEG-phosphate ATPS on the basis of the measured B22 and B23 values is presented.

  2. Phosphoprotein Stability in Clinical Tissue and Its Relevance for Reverse Phase Protein Microarray Technology

    PubMed Central

    Espina, Virginia; Mueller, Claudius; Liotta, Lance A.

    2013-01-01

    Phosphorylated proteins reflect the activity of specific cell signaling nodes in biological kinase protein networks. Cell signaling pathways can be either activated or deactivated depending on the phosphorylation state of the constituent proteins. The state of these kinase pathways reflects the in vivo activity of the cells and tissue at any given point in time. As such, cell signaling pathway information can be extrapolated to infer which phosphorylated proteins/pathways are driving an individual tumor’s growth. Reverse Phase Protein Microarrays (RPMA) are a sensitive and precise platform that can be applied to the quantitative measurement of hundreds of phosphorylated signal proteins from a small sample of tissue. Pre-analytical variability originating from tissue procurement and preservation may cause significant variability and bias in downstream molecular analysis. Depending on the ex vivo delay time in tissue processing, and the manner of tissue handling, protein biomarkers such as signal pathway phosphoproteins will be elevated or suppressed in a manner that does not represent the biomarker levels at the time of excision. Consequently, assessment of the state of these kinase networks requires stabilization, or preservation, of the phosphoproteins immediately post tissue procurement. We have employed reverse phase protein microarray analysis of phosphoproteins to study the factors influencing stability of phosphoproteins in tissue following procurement. Based on this analysis we have established tissue procurement guidelines for clinical research with an emphasis on quantifying phosphoproteins by RPMA. PMID:21901591

  3. Production of Dengue 2 Envelope Protein in the Yeast Saccharomyces Cerevisiae. Phase 1

    DTIC Science & Technology

    1990-02-15

    PRODUCTION OF DENGUE 2 ENVELOPE PROTEIN IN THE YEAST SACCHAROMYCES CEREVISIAE FINAL, PHASE I REPORT JOHN M. IVY KATHY HOUTCHENS FEBRUARY 15, 1990...SUBTITLE Production of Dengue 2 Envelope Protein in the Yeast Saccharomyces cerevisiae ( 6. AUTHOR(S) John M. Ivy Kathy Houtchens 7 PERFORMING...DISTRIBUTION CODE 13. ABSTRACT (Mammum 200 words) The four serotypes of dengue viruses are a leading cause of morbidity throughout the tropics and subtropics

  4. Simple Model Study of Phase Transition Properties of Isolated and Aggregated Protein

    NASA Astrophysics Data System (ADS)

    Ji, Yong-Yun; Yi, Wei-Qi; Zhang, Lin-Xi

    2011-03-01

    We investigate the phase transition properties of isolated and aggregated protein by exhaustive numerical study in the confined conformation space with maximally compact lattice model. The study within the confined conformation space shows some general folding properties. Various sequences show different folding properties: two-state folding, three-state folding and prion-like folding behavior. We find that the aggregated protein holds a more evident transition than isolated one and the transition temperature is generally lower than that in isolated case.

  5. Late Protein Synthesis-Dependent Phases in CTA Long-Term Memory: BDNF Requirement

    PubMed Central

    Martínez-Moreno, Araceli; Rodríguez-Durán, Luis F.; Escobar, Martha L.

    2011-01-01

    It has been proposed that long-term memory (LTM) persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF) is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related LTM when protein synthesis was inhibited. Our previous studies on the insular cortex (IC), a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA), have demonstrated that intracortical delivery of BDNF reverses the deficit in CTA memory caused by the inhibition of IC protein synthesis due to anisomycin administration during early acquisition. In this work, we first analyze whether CTA memory storage is protein synthesis-dependent in different time windows. We observed that CTA memory become sensible to protein synthesis inhibition 5 and 7 h after acquisition. Then, we explore the effect of BDNF delivery (2 μg/2 μl per side) in the IC during those late protein synthesis-dependent phases. Our results show that BDNF reverses the CTA memory deficit produced by protein synthesis inhibition in both phases. These findings support the notion that recurrent rounds of consolidation-like events take place in the neocortex for maintenance of CTA memory trace and that BDNF is an essential component of these processes. PMID:21960964

  6. Late Protein Synthesis-Dependent Phases in CTA Long-Term Memory: BDNF Requirement.

    PubMed

    Martínez-Moreno, Araceli; Rodríguez-Durán, Luis F; Escobar, Martha L

    2011-01-01

    It has been proposed that long-term memory (LTM) persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF) is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related LTM when protein synthesis was inhibited. Our previous studies on the insular cortex (IC), a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA), have demonstrated that intracortical delivery of BDNF reverses the deficit in CTA memory caused by the inhibition of IC protein synthesis due to anisomycin administration during early acquisition. In this work, we first analyze whether CTA memory storage is protein synthesis-dependent in different time windows. We observed that CTA memory become sensible to protein synthesis inhibition 5 and 7 h after acquisition. Then, we explore the effect of BDNF delivery (2 μg/2 μl per side) in the IC during those late protein synthesis-dependent phases. Our results show that BDNF reverses the CTA memory deficit produced by protein synthesis inhibition in both phases. These findings support the notion that recurrent rounds of consolidation-like events take place in the neocortex for maintenance of CTA memory trace and that BDNF is an essential component of these processes.

  7. Mass Spectrometry of Protein-Ligand Complexes: Enhanced Gas Phase Stability of Ribonuclease-Nucleotide Complexes

    PubMed Central

    Yin, Sheng; Xie, Yongming; Loo, Joseph A.

    2008-01-01

    Noncovalent protein-ligand complexes are readily detected by electrospray ionization mass spectrometry (ESI-MS). Ligand binding stoichiometry can be determined easily by the ESI-MS method. The ability to detect noncovalent protein-ligand complexes depends, however, on the stability of the complexes in the gas phase environment. Solution binding affinities may or may not be accurate predictors of their stability in vacuo. Complexes composed of cytidine nucleotides bound to ribonuclease A (RNase A) and ribonuclease S (RNase S) were detected by ESI-MS and were further analyzed by MS/MS. RNase A and RNase S share similar structures and biological activity. Subtilisin-cleavage of RNase A yields an S-peptide and an S-protein; the S-peptide and S-protein interact through hydrophobic interactions with a solution binding constant in the nanomolar range to generate an active RNase S. Cytidine nucleotides bind to the ribonucleases through electrostatic interactions with a solution binding constant in the micromolar range. Collisionally activated dissociation (CAD) of the 1:1 RNase A-CDP and CTP complexes yields cleavage of the covalent phosphate bonds of the nucleotide ligands, releasing CMP from the complex. CAD of the RNase S-CDP and CTP complexes dissociates the S-peptide from the remaining S-protein/nucleotide complex; further dissociation of the S-protein/nucleotide complex fragments a covalent phosphate bond of the nucleotide with subsequent release of CMP. Despite a solution binding constant favoring the S-protein/S-peptide complex, CDP/CTP remains electrostatically bound to the S-protein in the gas phase dissociation experiment. This study highlights the intrinsic stability of electrostatic interactions in the gas phase and the significant differences in solution and gas phase stabilities of noncovalent complexes that can result. PMID:18565758

  8. Development of porous polymer monoliths for reverse-phase chromatography of proteins.

    SciTech Connect

    Shepodd, Timothy J.; Stephens, Christopher P.

    2003-09-01

    The polymers developed in this project are intended for use as a stationary phase in reverse-phase chromatography of proteins, where the mobile phase is a solution of acetonitrile and a phosphate buffer, 6.6 pH. A full library of pore sizes have been developed ranging from 0.41{micro}m to 4.09 {micro}m; these pore sizes can be determined by the solvent ratio of tetrahydrofuran:methoxyethanol during polymerization. A column that can separate proteins in an isocratic mode would be a vast improvement from the common method of separating proteins through gradient chromatography using multiple solvents. In the stationary phase, the main monomers have hydrophobic tails, lauryl acrylate and steryl acrylate. Separations of small hydrophobic molecules and peptides (trial molecules) have efficiencies of 24,000-33,000 theoretical plates m{sup -1}. The combination of a highly non-polar stationary phase and a mobile phase where the polarity can be controlled provide for excellent separation.

  9. Acute-phase protein α1-antitrypsin--a novel regulator of angiopoietin-like protein 4 transcription and secretion.

    PubMed

    Frenzel, Eileen; Wrenger, Sabine; Immenschuh, Stephan; Koczulla, Rembert; Mahadeva, Ravi; Deeg, H Joachim; Dinarello, Charles A; Welte, Tobias; Marcondes, A Mario Q; Janciauskiene, Sabina

    2014-06-01

    The angiopoietin-like protein 4 (angptl4, also known as peroxisome proliferator-activated receptor [PPAR]γ-induced angiopoietin-related protein) is a multifunctional protein associated with acute-phase response. The mechanisms accounting for the increase in angptl4 expression are largely unknown. This study shows that human α1-antitrypsin (A1AT) upregulates expression and release of angplt4 in human blood adherent mononuclear cells and in primary human lung microvascular endothelial cells in a concentration- and time-dependent manner. Mononuclear cells treated for 1 h with A1AT (from 0.1 to 4 mg/ml) increased mRNA of angptl4 from 2- to 174-fold, respectively, relative to controls. In endothelial cells, the maximal effect on angptl4 expression was achieved at 8 h with 2 mg/ml A1AT (11-fold induction versus controls). In 10 emphysema patients receiving A1AT therapy (Prolastin), plasma angptl4 levels were higher relative to patients without therapy (nanograms per milliliter, mean [95% confidence interval] 127.1 [99.5-154.6] versus 76.8 [54.8-98.8], respectively, p = 0.045) and correlated with A1AT levels. The effect of A1AT on angptl4 expression was significantly diminished in cells pretreated with a specific inhibitor of ERK1/2 activation (UO126), irreversible and selective PPARγ antagonist (GW9662), or genistein, a ligand for PPARγ. GW9662 did not alter the ability of A1AT to induce ERK1/2 phosphorylation, suggesting that PPARγ is a critical mediator in the A1AT-driven angptl4 expression. In contrast, the forced accumulation of HIF-1α, an upregulator of angptl4 expression, enhanced the effect of A1AT. Thus, acute-phase protein A1AT is a physiological regulator of angptl4, another acute-phase protein.

  10. Smartphone apps in microbiology--is better regulation required?

    PubMed

    Visvanathan, A; Hamilton, A; Brady, R R W

    2012-07-01

    Increasing diversity of available medical applications (apps) has led to their widespread use in healthcare delivery. However, app involvement in diagnosis and patient management has raised concerns, specifically regarding accuracy and reliability of content. Here, we report on the contemporary range of microbiology-themed apps and prevalence of medical professional involvement in app development. Of 94 microbiology-themed apps identified, only 34% had stated medical professional involvement. The lack of such involvement in app design is concerning and undermines consumers' ability to be informed regarding quality of content. We propose that increased regulatory measures are introduced to safeguard patient welfare.

  11. Challenge with lipopolysaccharides or Freund's adjuvant? What is the best option to trigger acute phase protein production in broilers?

    PubMed

    Koppenol, A; Everaert, N; Buyse, J; Delezie, E

    2015-04-01

    Broilers were injected at 10 days of age with either Escherichia coli lipopolysaccharides (LPS) or with Freund's adjuvants (FA) to investigate its triggering effect on the acute phase reaction (APR). First the kinetics of certain APP was studied by sampling blood 4 h, 8 h, 12 h and 24 h post injection with LPS. Ovotransferrin (OVT) and α-1 acid glycoprotein (AGP) concentration increased with time post injection (PI) with LPS to reach a plateau at 12 and 24 h PI. Caeruloplasmin (CP) did not increase with time PI. Compared to injection with phosphate buffered saline, OVT concentrations were higher when injecting chicks with LPS at all time points PI. At 24 h PI, LPS injection resulted in higher OVT and AGP concentration compared to injection with FA. It is recommended to use LPS instead of FA to trigger the APR. The best time point to sample blood for APP determination is 24 h PI.

  12. Phase separation and bistability in a three-dimensional model for protein domain formation at biomembranes

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Bär, Markus

    2010-12-01

    Proteins in living cells interact with membranes. They may bind to or unbind from the membrane to the cytosol depending on the lipid composition of the membrane and their interaction with cytosolic enzymes. Moreover, proteins can accumulate at the membrane and assemble in spatial domains. Here, a simple model of protein cycling at biomembranes is studied, when the total number of proteins is conserved. Specifically, we consider the spatio-temporal dynamics of MARCKS proteins and their interactions with enzymes facilitating translocation from and rebinding to the membrane. The model exhibits two qualitatively different mechanisms of protein domain formation: phase separation related to a long-wave instability of a membrane state with homogeneous protein coverage and stable coexistence of two states with different homogeneous protein coverage in bistable media. We evaluate the impact of the cytosolic volume on the occurrence of protein pattern formation by simulations in a three-dimensional model. We show that the explicit treatment of the volume in the model leads to an effective rescaling of the reaction rates. For a simplified model of protein cycling, we can derive analytical expressions for the rescaling coefficients and verify them by direct simulations with the complete three-dimensional model.

  13. Gleevec shifts APP processing from a β-cleavage to a nonamyloidogenic cleavage

    PubMed Central

    Netzer, William J.; Bettayeb, Karima; Sinha, Subhash C.; Flajolet, Marc; Bustos, Victor

    2017-01-01

    Neurotoxic amyloid-β peptides (Aβ) are major drivers of Alzheimer’s disease (AD) and are formed by sequential cleavage of the amyloid precursor protein (APP) by β-secretase (BACE) and γ-secretase. Our previous study showed that the anticancer drug Gleevec lowers Aβ levels through indirect inhibition of γ-secretase activity. Here we report that Gleevec also achieves its Aβ-lowering effects through an additional cellular mechanism. It renders APP less susceptible to proteolysis by BACE without inhibiting BACE enzymatic activity or the processing of other BACE substrates. This effect closely mimics the phenotype of APP A673T, a recently discovered mutation that protects carriers against AD and age-related cognitive decline. In addition, Gleevec induces formation of a specific set of APP C-terminal fragments, also observed in cells expressing the APP protective mutation and in cells exposed to a conventional BACE inhibitor. These Gleevec phenotypes require an intracellular acidic pH and are independent of tyrosine kinase inhibition, given that a related compound lacking tyrosine kinase inhibitory activity, DV2-103, exerts similar effects on APP metabolism. In addition, DV2-103 accumulates at high concentrations in the rodent brain, where it rapidly lowers Aβ levels. This study suggests that long-term treatment with drugs that indirectly modulate BACE processing of APP but spare other BACE substrates and achieve therapeutic concentrations in the brain might be effective in preventing or delaying the onset of AD and could be safer than nonselective BACE inhibitor drugs. PMID:28115709

  14. Effective protein separation by coupling hydrophobic interaction and reverse phase chromatography for top-down proteomics.

    PubMed

    Xiu, Lichen; Valeja, Santosh G; Alpert, Andrew J; Jin, Song; Ge, Ying

    2014-08-05

    One of the challenges in proteomics is the proteome's complexity, which necessitates the fractionation of proteins prior to the mass spectrometry (MS) analysis. Despite recent advances in top-down proteomics, separation of intact proteins remains challenging. Hydrophobic interaction chromatography (HIC) appears to be a promising method that provides high-resolution separation of intact proteins, but unfortunately the salts conventionally used for HIC are incompatible with MS. In this study, we have identified ammonium tartrate as a MS-compatible salt for HIC with comparable separation performance as the conventionally used ammonium sulfate. Furthermore, we found that the selectivity obtained with ammonium tartrate in the HIC mobile phases is orthogonal to that of reverse phase chromatography (RPC). By coupling HIC and RPC as a novel two-dimensional chromatographic method, we have achieved effective high-resolution intact protein separation as demonstrated with standard protein mixtures and a complex cell lysate. Subsequently, the separated intact proteins were identified by high-resolution top-down MS. For the first time, these results have shown the high potential of HIC as a high-resolution protein separation method for top-down proteomics.

  15. Triton X-114 phase separation in the isolation and purification of mouse liver microsomal membrane proteins.

    PubMed

    Mathias, Rommel A; Chen, Yuan-Shou; Kapp, Eugene A; Greening, David W; Mathivanan, Suresh; Simpson, Richard J

    2011-08-01

    Integral membrane proteins (IMPs) mediate several cellular functions including cell adhesion, ion and nutrient transport, and cell signalling. IMPs are typically hard to isolate and purify due to their hydrophobic nature and low cellular abundance, however, microsomes are small lipid vesicles rich in IMPs, which form spontaneously when cells are mechanically disrupted. In this study, we have employed mouse liver microsomes as a model for optimising a method for IMP isolation and characterisation. Microsomes were collected by differential centrifugation, purified with sodium carbonate, and subjected to GeLC-MS/MS analysis. A total of 1124 proteins were identified in the microsome fraction, with 47% (524/1124) predicted by TMHMM to contain at least one transmembrane domain (TMD). The ability of phase partitioning using the detergent Triton X-114 (TX-114) to further enrich for membrane proteins was evaluated. Microsomes were subjected to successive rounds of solubility-based phase separation, with proteins partitioning into the aqueous phase, detergent phase, or TX-114-insoluble pellet fraction. GeLC-MS/MS analysis of the three TX-114 fractions identified 1212 proteins, of which 146 were not detected in the un-fractionated microsome sample. Conspicuously, IMPs partitioned to the detergent phase, with 56% (435/770) of proteins identified in that fraction containing at least one TMD. GO Slim characterisation of the microsome proteome revealed enrichment of proteins from the endoplasmic reticulum, mitochondria, Golgi apparatus, endosome, and cytoplasm. Further, enzymes including monooxygenases were well represented with 35 cytochrome P450 identifications (CYPs 1A2, 2A5, 2A12, 2B10, 2C29, 2C37, 2C39, 2C44, 2C50, 2C54. 2C67, 2C68, 2C70, 2D10, 2D11, 2D22, 2D26, 2D9, 2E1, 2F2, 2J5, 2U1, 3A11, 3A13, 3A25, 4A10, 4A12A, 4A12B, 4F13, 4F14, 4F15, 4V3, 51,7B1, and 8B1). Evaluation of biological processes showed enrichment of proteins involved in fatty acid biosynthesis and

  16. Autism, Alzheimer disease, and fragile X: APP, FMRP, and mGluR5 are molecular links.

    PubMed

    Sokol, D K; Maloney, B; Long, J M; Ray, B; Lahiri, D K

    2011-04-12

    The present review highlights an association between autism, Alzheimer disease (AD), and fragile X syndrome (FXS). We propose a conceptual framework involving the amyloid-β peptide (Aβ), Aβ precursor protein (APP), and fragile X mental retardation protein (FMRP) based on experimental evidence. The anabolic (growth-promoting) effect of the secreted α form of the amyloid-β precursor protein (sAPPα) may contribute to the state of brain overgrowth implicated in autism and FXS. Our previous report demonstrated that higher plasma sAPPα levels associate with more severe symptoms of autism, including aggression. This molecular effect could contribute to intellectual disability due to repression of cell-cell adhesion, promotion of dense, long, thin dendritic spines, and the potential for disorganized brain structure as a result of disrupted neurogenesis and migration. At the molecular level, APP and FMRP are linked via the metabotropic glutamate receptor 5 (mGluR5). Specifically, mGluR5 activation releases FMRP repression of APP mRNA translation and stimulates sAPP secretion. The relatively lower sAPPα level in AD may contribute to AD symptoms that significantly contrast with those of FXS and autism. Low sAPPα and production of insoluble Aβ would favor a degenerative process, with the brain atrophy seen in AD. Treatment with mGluR antagonists may help repress APP mRNA translation and reduce secretion of sAPP in FXS and perhaps autism.

  17. Association of TrkA and APP Is Promoted by NGF and Reduced by Cell Death-Promoting Agents.

    PubMed

    Canu, Nadia; Pagano, Ilaria; La Rosa, Luca Rosario; Pellegrino, Marsha; Ciotti, Maria Teresa; Mercanti, Delio; Moretti, Fabiola; Sposato, Valentina; Triaca, Viviana; Petrella, Carla; Maruyama, Ichiro N; Levi, Andrea; Calissano, Pietro

    2017-01-01

    The amyloid precursor protein (APP) interacts with the tropomyosin receptor kinase A (TrkA) in normal rat, mouse, and human brain tissue but not in Alzheimer's disease (AD) brain tissue. However, it has not been reported whether the two proteins interact directly, and if so, which domains are involved. Clarifying these points will increase our understanding of the role and regulation of the TrkA/APP interaction in normal brain functioning as well as in AD. Here we addressed these questions using bimolecular fluorescence complementation (BiFC) and the proximity ligation assay (PLA). We demonstrated that exogenously expressed APP and TrkA associate through their juxtamembrane/transmembrane domains, to form a complex that localizes mainly to the plasma membrane, endoplasmic reticulum (ER) and Golgi. Formation of the complex was inhibited by p75NTR, ShcC and Mint-2. Importantly, we demonstrated that the association between endogenous APP and TrkA in primary septal neurons were modified by NGF, or by drugs that either inhibit ER-to-Golgi transport or perturb microtubules and microfilaments. Interestingly, several agents that induce cell death [amyloid β (Aβ)-peptide, staurosporine and rapamycin], albeit via different mechanisms, all caused dissociation of APP/TrkA complexes and increased production of C-terminal fragment (β-CTF) APP fragment. These findings open new perspectives for investigating the interplay between these proteins during neurodegeneration and AD.

  18. Association of TrkA and APP Is Promoted by NGF and Reduced by Cell Death-Promoting Agents

    PubMed Central

    Canu, Nadia; Pagano, Ilaria; La Rosa, Luca Rosario; Pellegrino, Marsha; Ciotti, Maria Teresa; Mercanti, Delio; Moretti, Fabiola; Sposato, Valentina; Triaca, Viviana; Petrella, Carla; Maruyama, Ichiro N.; Levi, Andrea; Calissano, Pietro

    2017-01-01

    The amyloid precursor protein (APP) interacts with the tropomyosin receptor kinase A (TrkA) in normal rat, mouse, and human brain tissue but not in Alzheimer’s disease (AD) brain tissue. However, it has not been reported whether the two proteins interact directly, and if so, which domains are involved. Clarifying these points will increase our understanding of the role and regulation of the TrkA/APP interaction in normal brain functioning as well as in AD. Here we addressed these questions using bimolecular fluorescence complementation (BiFC) and the proximity ligation assay (PLA). We demonstrated that exogenously expressed APP and TrkA associate through their juxtamembrane/transmembrane domains, to form a complex that localizes mainly to the plasma membrane, endoplasmic reticulum (ER) and Golgi. Formation of the complex was inhibited by p75NTR, ShcC and Mint-2. Importantly, we demonstrated that the association between endogenous APP and TrkA in primary septal neurons were modified by NGF, or by drugs that either inhibit ER-to-Golgi transport or perturb microtubules and microfilaments. Interestingly, several agents that induce cell death [amyloid β (Aβ)-peptide, staurosporine and rapamycin], albeit via different mechanisms, all caused dissociation of APP/TrkA complexes and increased production of C-terminal fragment (β-CTF) APP fragment. These findings open new perspectives for investigating the interplay between these proteins during neurodegeneration and AD. PMID:28197073

  19. Identification and characterization of BipA, a Bordetella Bvg-intermediate phase protein.

    PubMed

    Stockbauer, K E; Fuchslocher, B; Miller, J F; Cotter, P A

    2001-01-01

    The Bordetella BvgAS sensory transduction system has traditionally been viewed as controlling a transition between two distinct phenotypic phases: the Bvg(+) or virulent phase and the Bvg(-) or avirulent phase. Recently, we identified a phenotypic phase of Bordetella bronchiseptica that displays reduced virulence in a rat model of respiratory infection concomitant with increased ability to survive nutrient deprivation. Characterization of this phase, designated Bvg-intermediate (Bvg(i)), indicated the presence of antigens that are maximally, if not exclusively, expressed in this phase and therefore suggested the existence of a previously unidentified class of Bvg-regulated genes. We now report the identification and characterization of a Bvg(i) phase protein, BipA (Bvg-intermediate phase protein A), and its structural gene, bipA. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicates that bipA is expressed maximally under Bvgi phase conditions and thus represents the first identified Bvgi phase gene. bipA encodes a 1578-amino-acid protein that shares amino acid sequence similarity at its N-terminus with the proposed outer membrane localization domains of intimin (Int) of enteropathogenic and enterohaemorrhagic Escherichia coli and invasin (Inv) of Yersinia spp. Although not apparent at the amino acid level, BipA is also similar to Int and Inv in that the proposed membrane-spanning domain is followed by several 90-amino-acid repeats and a distinct C-terminal domain. Localization studies using an antibody directed against the C-terminus of BipA indicated that its C-terminus is exposed on the bacterial cell surface. Western blot analysis with this same antibody indicated that BipA homologues are expressed in Bvg(i) phase Bordetella pertussis and Bordetella parapertussis. Comparison of a Delta bipA strain with wild-type B. bronchiseptica indicated that BipA is not required for Bvg(i) phase-specific aggregative adherence to rat lung epithelial cells

  20. Compliance of blood donation apps with mobile OS usability guidelines.

    PubMed

    Ouhbi, Sofia; Fernández-Alemán, José Luis; Pozo, José Rivera; Bajta, Manal El; Toval, Ambrosio; Idri, Ali

    2015-06-01

    The aim of this paper is to employ the guidelines of Android, iOS, Blackberry and Windows Phone to analyze the usability compliance of free blood donation (BD) apps. An analysis process based on a systematic review protocol is used to select free BD apps. An assessment is conducted using a questionnaire composed of 13 questions concerning the compliance of free BD apps with Android, Blackberry, iOS and Windows Phone usability guidelines. A total of 133 free BD apps have been selected from the 188 BD apps identified. Around 63% of the free BD apps selected have a good compliance with mobile OS usability recommendations. Around 72% of Android, 57% of Windows Phone, 33% of iOS and 33% of Blackberry BD apps have a high usability score. The aspect of BD app behavior should be improved along with some style components: the use of pictures to explain ideas and the adaptation of the app to both horizontal and vertical orientations. Structure patterns should also be used to improve the structure aspect of a BD app. Usability is a quality aspect that should be improved in current BD apps. Our study provides smartphone users with a list of usable free BD apps and BD app developers with recommendations.

  1. easyHealthApps: e-Health Apps dynamic generation for smartphones & tablets.

    PubMed

    Paschou, Mersini; Sakkopoulos, Evangelos; Tsakalidis, Athanasios

    2013-06-01

    Mobile phones and especially smartphones have been embraced by a rapidly increasing number of people worldwide and this trend is expected to evolve even more in the years to come. There are numerous smartphone Apps that record critical medical data in an effort to solve a particular health issue each time. We studied such applications and not surprisingly, we have found that development and design effort is often repeated. Software patterns have been detected to exist, however re-usability has not been enforced. This leads to lost programming manpower and to increased probability of repeating bugs in Apps. Moreover, at the moment smartphone e-Health Apps demand time, effort and costs for development. Unfortunately even simple data recording Apps are practically impossible to be produced by multiple health domain users who are not developers. In this work, we propose, design and implement a simple and integrated solution which gives healthcare professionals and researchers the ability to create their own data intensive smartphone applications, independent of the desired healthcare domain. The proposed approach applies efficient software techniques that hide development from the users and enable App creation through a simple Web User Interface. The Apps produced are in native format and it is possible to dynamically receive m-Health business logic and the chosen UI. Evaluation of the proposed solution has shown that the generated Apps are functionally and UI equivalent to human-coded Apps according to a number of comparison parameters. Furthermore, e-Health professionals show particular interest in developing Apps on their own for a particular domain they focus on.

  2. An alternative scenario for the formation of specialized protein nano-domains (cluster phases) in biomembranes

    NASA Astrophysics Data System (ADS)

    Destainville, N.

    2010-09-01

    We discuss a realistic scenario, accounting for the existence of sub-micrometric protein domains in cell membranes. At the biological level, such membrane domains have been shown to be specialized, in order to perform a determined biological task, in the sense that they gather one or a few protein species out of the hundreds of different ones that a cell membrane may contain. By analyzing the balance between mixing entropy and protein affinities, we propose that such protein sorting in distinct domains can be explained without appealing to pre-existing lipidic micro-phase separations, as in the lipid raft scenario. We show that the proposed scenario is compatible with known physical interactions between membrane proteins, even if thousands of different species coexist.

  3. Phase Behavior of DNA in the Presence of DNA-Binding Proteins

    PubMed Central

    Le Treut, Guillaume; Képès, François; Orland, Henri

    2016-01-01

    To characterize the thermodynamical equilibrium of DNA chains interacting with a solution of nonspecific binding proteins, we implemented a Flory-Huggins free energy model. We explored the dependence on DNA and protein concentrations of the DNA collapse. For physiologically relevant values of the DNA-protein affinity, this collapse gives rise to a biphasic regime with a dense and a dilute phase; the corresponding phase diagram was computed. Using an approach based on Hamiltonian paths, we show that the dense phase has either a molten globule or a crystalline structure, depending on the DNA bending rigidity, which is influenced by the ionic strength. These results are valid at the thermodynamical equilibrium and therefore should be consistent with many biological processes, whose characteristic timescales range typically from 1 ms to 10 s. Our model may thus be applied to biological phenomena that involve DNA-binding proteins, such as DNA condensation with crystalline order, which occurs in some bacteria to protect their chromosome from detrimental factors; or transcription initiation, which occurs in clusters called transcription factories that are reminiscent of the dense phase characterized in this study. PMID:26745409

  4. The effect of chronic ammonia exposure on acute phase proteins, immunoglobulin and cytokines in laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia is a potential health hazard to both humans and animals, causing systemic low-grade inflammation based on its levels and durations. The objective of this study was to examine the effect of 45 weeks of exposure to 30 ppm NH3 on the concentrations of acute phase proteins, immunoglobulins and c...

  5. The diagnostic accuracy of acute phase proteins and proinflammatory cytokines in sheep with pneumonic pasteurellosis

    PubMed Central

    Elmoslemany, Ahmed M.

    2016-01-01

    The goal of this study was to assess the diagnostic accuracy of acute phase proteins and proinflammatory cytokines in sheep with pneumonic pasteurellosis. Blood samples were collected from 56 sheep (36 naturally infected with Pasteurella multocida and 20 healthy controls) belonging to one farm in Eastern region, Saudi Arabia. Serum samples were evaluated for acute phase proteins (Haptoglobin (Hp), serum amyloid A (SAA) and fibrinogen (Fb)), and the proinflammatory cytokines (interleukins (IL-1α, IL-1β, and IL-6), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-ϒ)). Additionally, nasopharyngeal swabs and bronchoalveolar lavages were collected from all animals for bacteriological examinations. Receiver operating characteristic curve was used to assess the diagnostic performance of each parameter. All parameters showed moderate to high degree of positive correlation with case-control status. There was no significant difference in the area under the curve (AUC) among acute phase proteins; however, both Hp and SAA showed better sensitivity and specificity than Fb. The proinflammatory cytokines (IL1-α, IL1-β, and IL6) showed similar and highly accurate diagnostic performance (AUC > 0.9), whereas IFN-ϒ was moderately accurate (AUC = 0.79). In conclusion, this study confirms the value of acute phase proteins and cytokines as diagnostic biomarkers of naturally occuring pneumonic pasteurellosis in sheep. PMID:27547520

  6. Studies of proteinograms in dermatophytes by disc electrophoresis. 1. Protein bands in relation to growth phase

    NASA Technical Reports Server (NTRS)

    Danev, P.; Friedrich, E.; Balabanov, V.

    1983-01-01

    Homogenates were prepared from various growth phases of Microsporum gypseum grown on different amino acids as the nitrogen source. When analyzed on 7.5% polyacrylamide disc gels, the water-soluble proteins in these homogenates gave essentially identical banding patterns.

  7. Circulating Microbial Products and Acute Phase Proteins as Markers of Pathogenesis in Lymphatic Filarial Disease

    PubMed Central

    Anuradha, R.; George, P. Jovvian; Pavan Kumar, N.; Fay, Michael P.; Kumaraswami, V.; Nutman, Thomas B.; Babu, Subash

    2012-01-01

    Lymphatic filariasis can be associated with development of serious pathology in the form of lymphedema, hydrocele, and elephantiasis in a subset of infected patients. Dysregulated host inflammatory responses leading to systemic immune activation are thought to play a central role in filarial disease pathogenesis. We measured the plasma levels of microbial translocation markers, acute phase proteins, and inflammatory cytokines in individuals with chronic filarial pathology with (CP Ag+) or without (CP Ag−) active infection; with clinically asymptomatic infections (INF); and in those without infection (endemic normal [EN]). Comparisons between the two actively infected groups (CP Ag+ compared to INF) and those without active infection (CP Ag− compared to EN) were used preliminarily to identify markers of pathogenesis. Thereafter, we tested for group effects among all the four groups using linear models on the log transformed responses of the markers. Our data suggest that circulating levels of microbial translocation products (lipopolysaccharide and LPS-binding protein), acute phase proteins (haptoglobin and serum amyloid protein-A), and inflammatory cytokines (IL-1β, IL-12, and TNF-α) are associated with pathogenesis of disease in lymphatic filarial infection and implicate an important role for circulating microbial products and acute phase proteins. PMID:22685406

  8. Alzheimer's-related endosome dysfunction in Down syndrome is Abeta-independent but requires APP and is reversed by BACE-1 inhibition.

    PubMed

    Jiang, Ying; Mullaney, Kerry A; Peterhoff, Corrinne M; Che, Shaoli; Schmidt, Stephen D; Boyer-Boiteau, Anne; Ginsberg, Stephen D; Cataldo, Anne M; Mathews, Paul M; Nixon, Ralph A

    2010-01-26

    An additional copy of the beta-amyloid precursor protein (APP) gene causes early-onset Alzheimer's disease (AD) in trisomy 21 (DS). Endosome dysfunction develops very early in DS and AD and has been implicated in the mechanism of neurodegeneration. Here, we show that morphological and functional endocytic abnormalities in fibroblasts from individuals with DS are reversed by lowering the expression of APP or beta-APP-cleaving enzyme 1 (BACE-1) using short hairpin RNA constructs. By contrast, endosomal pathology can be induced in normal disomic (2N) fibroblasts by overexpressing APP or the C-terminal APP fragment generated by BACE-1 (betaCTF), all of which elevate the levels of betaCTFs. Expression of a mutant form of APP that cannot undergo beta-cleavage had no effect on endosomes. Pharmacological inhibition of APP gamma-secretase, which markedly reduced Abeta production but raised betaCTF levels, also induced AD-like endosome dysfunction in 2N fibroblasts and worsened this pathology in DS fibroblasts. These findings strongly implicate APP and the betaCTF of APP, and exclude Abeta and the alphaCTF, as the cause of endocytic pathway dysfunction in DS and AD, underscoring the potential multifaceted value of BACE-1 inhibition in AD therapeutics.

  9. Determination of gas phase protein ion densities via ion mobility analysis with charge reduction.

    PubMed

    Maisser, Anne; Premnath, Vinay; Ghosh, Abhimanyu; Nguyen, Tuan Anh; Attoui, Michel; Hogan, Christopher J

    2011-12-28

    We use a charge reduction electrospray (ESI) source and subsequent ion mobility analysis with a differential mobility analyzer (DMA, with detection via both a Faraday cage electrometer and a condensation particle counter) to infer the densities of single and multiprotein ions of cytochrome C, lysozyme, myoglobin, ovalbumin, and bovine serum albumin produced from non-denaturing (20 mM aqueous ammonium acetate) and denaturing (1 : 49.5 : 49.5, formic acid : methanol : water) ESI. Charge reduction is achieved through use of a Po-210 radioactive source, which generates roughly equal concentrations of positive and negative ions. Ions produced by the source collide with and reduce the charge on ESI generated drops, preventing Coulombic fissions, and unlike typical protein ESI, leading to gas-phase protein ions with +1 to +3 excess charges. Therefore, charge reduction serves to effectively mitigate any role that Coulombic stretching may play on the structure of the gas phase ions. Density inference is made via determination of the mobility diameter, and correspondingly the spherical equivalent protein volume. Through this approach it is found that for both non-denaturing and denaturing ESI-generated ions, gas-phase protein ions are relatively compact, with average densities of 0.97 g cm(-3) and 0.86 g cm(-3), respectively. Ions from non-denaturing ESI are found to be slightly more compact than predicted from the protein crystal structures, suggesting that low charge state protein ions in the gas phase are slightly denser than their solution conformations. While a slight difference is detected between the ions produced with non-denaturing and denaturing ESI, the denatured ions are found to be much more dense than those examined previously by drift tube mobility analysis, in which charge reduction was not employed. This indicates that Coulombic stretching is typically what leads to non-compact ions in the gas-phase, and suggests that for gas phase

  10. The intrinsically disordered C-RING biomineralization protein, AP7, creates protein phases that introduce nanopatterning and nanoporosities into mineral crystals.

    PubMed

    Chang, Eric P; Russ, Jennie A; Verch, Andreas; Kröger, Roland; Estroff, Lara A; Evans, John Spencer

    2014-07-15

    We report an interesting process whereby the formation of nanoparticle assemblies on and nanoporosities within calcite crystals is directed by an intrinsically disordered C-RING mollusk shell nacre protein, AP7. Under mineralization conditions, AP7 forms protein phases that direct the nucleation of ordered calcite nanoparticles via a repetitive protein phase deposition process onto calcite crystals. These organized nanoparticles are separated by gaps or spaces that become incorporated into the forming bulk crystal as nanoporosities. This is an unusual example of organized nanoparticle biosynthesis and mineral modification directed by a C-RING protein phase.

  11. The Intrinsically Disordered C-RING Biomineralization Protein, AP7, Creates Protein Phases That Introduce Nanopatterning and Nanoporosities into Mineral Crystals

    PubMed Central

    2015-01-01

    We report an interesting process whereby the formation of nanoparticle assemblies on and nanoporosities within calcite crystals is directed by an intrinsically disordered C-RING mollusk shell nacre protein, AP7. Under mineralization conditions, AP7 forms protein phases that direct the nucleation of ordered calcite nanoparticles via a repetitive protein phase deposition process onto calcite crystals. These organized nanoparticles are separated by gaps or spaces that become incorporated into the forming bulk crystal as nanoporosities. This is an unusual example of organized nanoparticle biosynthesis and mineral modification directed by a C-RING protein phase. PMID:24977921

  12. Levels of complement components, immunoglobulins and acute phase proteins in plasma during aging in Nigeria.

    PubMed

    Oyeyinka, G O; Salimonu, L S

    1999-01-01

    Plasma samples from Nigerians aged 6-95 years were examined for their content of complement components (C3, C4, factor B-Bf), immuloglobins (IgG, IgA, IgM IgD) and acute phase proteins (transferrin, albumin, C-reactive protein--CRP, alpha-2-macroglobulin). Albumin, was estimated colorimetrically and the other components by the single radial immunodiffusion techniques. No significant age-related changes in mean values of the four immunobulins and the four acute phase proteins could be demonstrated. Also, the mean values for C3 and Bf did not change significantly with age but C4 values rose significantly with increasing age (r -0.232: P < 0.01).

  13. Gas-phase IR spectra of intact [alpha]-helical coiled coil protein complexes

    NASA Astrophysics Data System (ADS)

    Pagel, Kevin; Kupser, Peter; Bierau, Frauke; Polfer, Nicolas C.; Steill, Jeffrey D.; Oomens, Jos; Meijer, Gerard; Koksch, Beate; von Helden, Gert

    2009-06-01

    Electrospray ionization (ESI) is the softest ionization method that is currently available and it is widely accepted, that ESI generated ions of proteins and protein assemblies at certain conditions retain characteristic aspects of their solution-state conformation. ESI mass spectrometry (MS) therefore evolved as a useful tool to obtain information on composition, stoichiometry, and dynamics of non-covalently associated protein complexes. While tertiary structure information of proteins can be obtained from ion mobility spectrometry (IMS), only a few techniques yield direct information on the secondary structure of gas-phase peptides and proteins. We present here the mid-IR spectroscopic secondary structural analysis of three de novo designed [alpha]-helical coiled coil model peptides and their non-covalently associated complexes in the gas-phase. The conformational stability of such coiled coil peptides in solution is primarily driven by aggregation. Isolated monomers usually remain unfolded. Two of the investigated peptides were designed to assemble into stable [alpha]-helical complexes in acidic solution, while the third one remains monomeric and unfolded at these conditions. Monomer ions of all three peptides show comparable photodissociation IR spectra and therefore suggest an unfolded conformation in the gas phase. In contrast, considerable CO stretch (amide-I) and N-H bend (amide-II) band shifts have been observed for the dimers which is consistent with an elevated H-bond content. These findings provide evidence that at least a fraction of the condensed phase [alpha]-helical structure is retained in the gas-phase coiled coil complexes.

  14. Liquid crystalline phase behavior of protein fibers in water: experiments versus theory.

    PubMed

    Jung, Jin-Mi; Mezzenga, Raffaele

    2010-01-05

    We have developed a new method allowing the study of the thermodynamic phase behavior of mesoscopic colloidal systems consisting of amyloid protein fibers in water, obtained by heat denaturation and aggregation of beta-lactoglobulin, a dairy protein. The fibers have a cross section of about 5.2 nm and two groups of polydisperse contour lengths: (i) long fibers of 1-20 microm, showing semiflexible behavior, and (ii) short rods of 100-200 nm long, obtained by cutting the long fibers via high-pressure homogenization. At pH 2 without salt, these fibers are highly charged and stable in water. We have studied the isotropic-nematic phase transition for both systems and compared our results with the theoretical values predicted by Onsager's theory. The experimentally measured isotropic-nematic phase transition was found to occur at 0.4% and at 3% for the long and short fibers, respectively. For both systems, this phase transition occurs at concentrations more than 1 order of magnitude lower than what is expected based on Onsager's theory. Moreover, at low enough pH, no intermediate biphasic region was observed between the isotropic phase and the nematic phase. The phase diagrams of both systems (pH vs concentration) showed similar, yet complex and rich, phase behavior. We discuss the possible physical fundamentals ruling the phase diagram as well as the discrepancy we observe for the isotropic-nematic phase transition between our experimental results and the predicted theoretical results. Our work highlights that systems formed by water-amyloid protein fibers are way too complex to be understood based solely on Onsager's theories. Experimental results are revisited in terms of the Flory's theory (1956) for suspensions of rods, which allows accounting for rod-solvent hydrophobic interactions. This theoretical approach allows explaining, on a semiquantitative basis, most of the discrepancies observed between the experimental results and Onsager's predictions. The sources of

  15. IL-10 Alters Immunoproteostasis in APP mice, Increasing Plaque Burden and Worsening Cognitive Behavior

    PubMed Central

    Chakrabarty, Paramita; Li, Andrew; Ceballos-Diaz, Carolina; Eddy, James A.; Funk, Cory C; Moore, Brenda; DiNunno, Nadia; Rosario, Awilda M; Cruz, Pedro E; Verbeeck, Christophe; Sacino, Amanda; Nix, Sarah; Janus, Christopher; Price, Nathan D; Das, Pritam; Golde, Todd E

    2014-01-01

    Summary Anti-inflammatory strategies are proposed to have beneficial effects in Alzheimer's disease. To explore how anti-inflammatory cytokine signaling affects Aβ pathology, we investigated the effects of adeno-associated virus (AAV2/1) mediated expression of Interleukin (IL)-10 in the brains of APP transgenic mouse models. IL-10 expression resulted in increased Aβ accumulation and impaired memory in APP mice. A focused transcriptome analysis revealed changes consistent with enhanced IL-10 signaling and increased ApoE expression in IL-10 expressing APP mice. ApoE protein was selectively increased in the plaque-associated insoluble cellular fraction, likely due to direct interaction with aggregated Aβ in the IL-10 expressing APP mice. Ex vivo studies also show that IL-10 and ApoE can individually impair glial Aβ phagocytosis. Our observations that IL-10 has an unexpected negative effect on Aβ proteostasis and cognition in APP mouse models demonstrate the complex interplay between innate immunity and proteostasis in neurodegenerative diseases, an interaction we call immunoproteostasis. PMID:25619653

  16. Phase variable DNA repeats in Neisseria gonorrhoeae influence transcription, translation, and protein sequence variation

    PubMed Central

    Zelewska, Marta A.; Pulijala, Madhuri; Spencer-Smith, Russell; Mahmood, Hiba-Tun-Noor A.; Norman, Billie; Churchward, Colin P.; Calder, Alan

    2016-01-01

    There are many types of repeated DNA sequences in the genomes of the species of the genus Neisseria, from homopolymeric tracts to tandem repeats of hundreds of bases. Some of these have roles in the phase-variable expression of genes. When a repeat mediates phase variation, reversible switching between tract lengths occurs, which in the species of the genus Neisseria most often causes the gene to switch between on and off states through frame shifting of the open reading frame. Changes in repeat tract lengths may also influence the strength of transcription from a promoter. For phenotypes that can be readily observed, such as expression of the surface-expressed Opa proteins or pili, verification that repeats are mediating phase variation is relatively straightforward. For other genes, particularly those where the function has not been identified, gathering evidence of repeat tract changes can be more difficult. Here we present analysis of the repetitive sequences that could mediate phase variation in the Neisseria gonorrhoeae strain NCCP11945 genome sequence and compare these results with other gonococcal genome sequences. Evidence is presented for an updated phase-variable gene repertoire in this species, including a class of phase variation that causes amino acid changes at the C-terminus of the protein, not previously described in N. gonorrhoeae. PMID:28348872

  17. Change of uterine histroph proteins during follicular and luteal phase in pigs.

    PubMed

    Lee, Sang-Hee; Song, Eun-Ji; Hwangbo, Yong; Lee, Seunghyung; Park, Choon-Keun

    2016-05-01

    The aim of this study was to examine protein expression patterns of uterine histroph (UH) during the follicular phase (FP) and luteal phase (LP) in pigs. Forty-nine common proteins were identified from FP and LP samples; five were significantly down-regulated (>1.5-fold), while 15 were significantly up-regulated (>1.5-fold) in LPUH compared with FPUH (P<0.05). The 20 differentially-expressed proteins are involved in cell proliferation, cell responses, translation, transport, and metabolism and their molecular functions include nucleic acid binding, oxygen activity, enzymatic activity, growth activity, iron binding, and redox binding. Protein expression of vascular endothelial growth factor D (VEGFD), coatomer subunit gamma-2 (G2COP), collagen alpha 4 chain (COL4), cysteine rich protein 2 (CRP2), myoglobin (MYG), and galactoside 3-L-fucosyltransferase 4 (FUT4) was analyzed by Western blotting. These proteins were significantly higher in LPUH compared to FPUH (P<0.05). These data expand our understanding of changes in the intrauterine environment during the pre-implantation period in pigs.

  18. Phase-specific optimization of multiple endotoxin-protein production with genetically engineered Bacillus thuringiensis.

    PubMed

    Yang, X M; Wang, S S

    2000-02-01

    An optimization approach was designed to specifically study the toxin-expression phase of the fermentation process of a genetically engineered Bacillus thuringiensis strain expressing dual toxin proteins (CryI and CryIII). The study has resulted in the discovery of important nutrient and process factors affecting toxin-protein yield. The results show that the existence of nitrogen sources in the medium during the toxin-expression phase is detrimental to the toxin-protein expression, while a high carbon-source level (40 g/l) encouraged protein expression. The study also suggests that the depletion of nitrogen source is the trigger for B. thuringiensis to initiate sporulation and toxin expression. A temperature setting of 28 degrees C for B. thuringiensis fermentation processes is optimal for protein yield, and reduces the oxygen requirement. It was found that the optimal conditions for spore yield and for toxin-protein yield were not the same, even though sporulation and toxin formation proceed simultaneously during the fermentation process. Scale-up studies were also conducted to confirm the optimal conditions obtained from a small-scale optimization study.

  19. Understanding and Capturing People’s Mobile App Privacy Preferences

    DTIC Science & Technology

    2013-10-28

    they collect might also include personal information such as users’ location, phone number, etc. Similar to targeted advertising libraries, mobile ...The percentage of users surprised about popular mobile apps using users’ location, phone ID and contact list. This figure shows the top 10 apps with...surprised by these popular mobile apps access users’ location, unique phone ID and contact list. Figure 17 shows the data related to the top 10 apps

  20. Overproduction, purification, crystallization and preliminary X-ray analysis of human Fe65-PTB2 in complex with the amyloid precursor protein intracellular domain

    SciTech Connect

    Radzimanowski, Jens; Beyreuther, Konrad; Sinning, Irmgard; Wild, Klemens

    2008-05-01

    Alzheimer’s disease is characterized by proteolytic processing of the amyloid precursor protein (APP), which releases the aggregation-prone amyloid-β (Aβ) peptide and liberates the intracellular domain (AICD) that interacts with various adaptor proteins. The crystallized AICD–Fe65-PTB2 complex is of central importance for APP translocation, nuclear signalling, processing and Aβ generation. Alzheimer’s disease is associated with typical brain deposits (senile plaques) that mainly contain the neurotoxic amyloid β peptide. This peptide results from proteolytic processing of the type I transmembrane protein amyloid precursor protein (APP). During this proteolytic pathway the APP intracellular domain (AICD) is released into the cytosol, where it associates with various adaptor proteins. The interaction of the AICD with the C-terminal phosphotyrosine-binding domain of Fe65 (Fe65-PTB2) regulates APP translocation, signalling and processing. Human AICD and Fe65-PTB2 have been cloned, overproduced and purified in large amounts in Escherichia coli. A complex of Fe65-PTB2 with the C-terminal 32 amino acids of the AICD gave well diffracting hexagonal crystals and data have been collected to 2.1 Å resolution. Initial phases obtained by the molecular-replacement method are of good quality and revealed well defined electron density for the substrate peptide.

  1. [Mechanism of thiol-dependence of acute phase proteins and serology of monospecific antisera in vitro].

    PubMed

    Kostiushov, V V; Kostiushova, N V; Pavlovich, S I; Sakhno, Iu P; Tymchyshyn, O L

    2001-01-01

    For the donors and for the patients with inflammatory processes is thiol-dependent the gear of immune responses in vitro an antigen--antibody on dynamics(changes) of change (+/- delta) of the contents SH- and S-S-group reaction mixtures. Thus, is conducted the analysis of interplay of proteins of an acute phase (CRP, orosomucoid and transferin) serums of a blood of the donors and patients with serology by related diagnostic (complementary) monospecific serums (MSS) against CRP (Anti-CRP), against Oroso (Anti-Oroso) i against Transf (Anti-Transf). Is established, that as against the donors, for the patients with inflammatory processes these reacting are accompanied by a phenomenon of a liberation of energy of Ag(+)-sensing non proteins SH-groups and they occur in supernatants of deprotheinized of reaction mixtures. At the same time, both for the donors, and for the patients, these reacting are accompanied modification by changes kept in repair (+/- delta) proteins SH- and S-S-rpy[symbol: see text], in integral reaction mixtures (in which one protein did not deposit). Such data testify, that the inflammatory process, apparently, can be accompanied by such rearrangement of a structurally functional condition of proteins of an acute phase, that under operating MSS in reaction mixtures descends labelised blended disulfide of communications between them and low molecular weight thiols. As a result of it there is a liberation of energy of Ag(+)-sensing non proteins SH-groups. This parameter can be used for an estimation of functional activity of proteins of an acute phase.

  2. Techtalk: Mobile Apps and College Mathematics

    ERIC Educational Resources Information Center

    Hoang, Theresa V.; Caverly, David C.

    2013-01-01

    In this column, the authors discuss apps useful in developing mathematical reasoning. They place these into a theoretical framework, suggesting how they could be used in an instructional model such as the Algorithmic Instructional Technique (AIT) developed by Vasquez (2003). This model includes four stages: modeling, practice, transition, and…

  3. Ebola - What You Need to Know app.

    PubMed

    Evans, Roger

    2015-02-03

    This app is the pocket companion to the Ebola in Africa section of the International SOS website. With headquarters in London and Singapore, International SOS is a company that provides medical, clinical and security services in 81 countries for organisations with international operations.

  4. Motivating Instruction? There's an App for That!

    ERIC Educational Resources Information Center

    Bruhn, Allison; Hirsch, Shanna; Vogelgesang, Kari

    2017-01-01

    Keeping students engaged in the curriculum is extremely important when attempting to close the achievement gap for students with and at risk for disabilities. This is particularly important for students with learning disabilities or behavior disorders. This article discusses the use of applications (apps) for mobile technologies that may be used…

  5. North Tyneside Perspective on Primary Science APP

    ERIC Educational Resources Information Center

    Keilty, Ged

    2010-01-01

    The status of primary science as a core subject has been gradually corroded in recent years, with the abolition of targets for science and the focus of the primary national strategy on literacy and numeracy. The NAIGS Committee were very well positioned within local authorities to pilot APP, but first had to write the criteria. Towards the end of…

  6. The App Squad: SLJ's Advisors Weigh in on Kids' Book Apps

    ERIC Educational Resources Information Center

    Ishizuka, Kathy

    2011-01-01

    In this article, "School Library Journal's" ("SLJ") advisors talk about book apps for kids. They discuss what they like, what one should look for in discerning the best for kids and teens, and where this all might be headed.

  7. A composite agarose-polyacrylamide matrix as two-dimensional hard support for solid-phase protein assays.

    PubMed

    Krajewski, Wladyslaw A

    2016-03-15

    The solid-phase protein assays using blotting membranes as hard support do not allow achieving the low background and sensitivity of protein staining in clear gels. The membrane opacity complicates imaging of results on standard lab documentation systems. We describe a low-cost transparent matrix that can be used as an alternative to polymeric membranes for solid-phase assays. Protein samples are spotted onto a dry film of composite agarose-polyacrylamide matrix covering standard glass microscopic slides. After rehydration in protein-fixing solution, matrix with protein samples can be detached from glass support and stained as conventional protein polyacrylamide gels.

  8. Realizing the promise of reverse phase protein arrays for clinical, translational, and basic research: a workshop report: the RPPA (Reverse Phase Protein Array) society.

    PubMed

    Akbani, Rehan; Becker, Karl-Friedrich; Carragher, Neil; Goldstein, Ted; de Koning, Leanne; Korf, Ulrike; Liotta, Lance; Mills, Gordon B; Nishizuka, Satoshi S; Pawlak, Michael; Petricoin, Emanuel F; Pollard, Harvey B; Serrels, Bryan; Zhu, Jingchun

    2014-07-01

    Reverse phase protein array (RPPA) technology introduced a miniaturized "antigen-down" or "dot-blot" immunoassay suitable for quantifying the relative, semi-quantitative or quantitative (if a well-accepted reference standard exists) abundance of total protein levels and post-translational modifications across a variety of biological samples including cultured cells, tissues, and body fluids. The recent evolution of RPPA combined with more sophisticated sample handling, optical detection, quality control, and better quality affinity reagents provides exquisite sensitivity and high sample throughput at a reasonable cost per sample. This facilitates large-scale multiplex analysis of multiple post-translational markers across samples from in vitro, preclinical, or clinical samples. The technical power of RPPA is stimulating the application and widespread adoption of RPPA methods within academic, clinical, and industrial research laboratories. Advances in RPPA technology now offer scientists the opportunity to quantify protein analytes with high precision, sensitivity, throughput, and robustness. As a result, adopters of RPPA technology have recognized critical success factors for useful and maximum exploitation of RPPA technologies, including the following: preservation and optimization of pre-analytical sample quality, application of validated high-affinity and specific antibody (or other protein affinity) detection reagents, dedicated informatics solutions to ensure accurate and robust quantification of protein analytes, and quality-assured procedures and data analysis workflows compatible with application within regulated clinical environments. In 2011, 2012, and 2013, the first three Global RPPA workshops were held in the United States, Europe, and Japan, respectively. These workshops provided an opportunity for RPPA laboratories, vendors, and users to share and discuss results, the latest technology platforms, best practices, and future challenges and

  9. Low-Budget Apps for Students of All Abilities

    ERIC Educational Resources Information Center

    VanWeelden, Kimberly; Heath, Julia

    2013-01-01

    With more than 850,000 apps currently on the market, there are multiple apps that can be used to help all students in music education, particularly those with special needs. This article lists low-budget apps useful for the elementary or secondary general music classroom.

  10. Using Apps to Support Disciplinary Literacy and Science Learning

    ERIC Educational Resources Information Center

    Castek, Jill; Beach, Richard

    2013-01-01

    Apps, specialized programs used on mobile computers, can be used in innovative ways to enhance science and literacy learning. With the skilled guidance of their teachers, students can exploit app affordances for learning and acquire disciplinary literacies unique to science. This article showcases apps that help students to access information,…

  11. English Language Teaching Apps: Positioning Parents and Young Learners

    ERIC Educational Resources Information Center

    Chik, Alice

    2014-01-01

    Since the introduction of iPads in 2010, the sales of tablet computers and mobile applications (apps) have grown exponentially. iPads and other tablets are marketed as learning tools, and many apps target learners as young as six months old. This article reports on a research project examining the unique features of English learning apps based on…

  12. Educational Behavior Apps and Wearable Devices: Current Research and Prospects

    ERIC Educational Resources Information Center

    Lowe, Heather

    2016-01-01

    Dartmouth and MIT have developed educational behavior apps and wearable devices that collect contiguous streams of data from student users. Given the consent of the user, the app collects information about a student's physical activity, sleep patterns, and location to form conjectures about social and academic behavior. These apps have the…

  13. Using the Modern Technology That Is the "App"

    ERIC Educational Resources Information Center

    Bernardelli, Alessio

    2013-01-01

    A few years ago, the sight of the letters APP would have made teachers in England think of the Assessing Pupils' Progress assessment approach introduced by the government. Now, when they see those same letters they mostly think about smartphone and tablet applications, shortened to "apps." With the thousands of apps available in the…

  14. Cleaning up That Mess: A Framework for Classifying Educational Apps

    ERIC Educational Resources Information Center

    Cherner, Todd; Dix , Judy; Lee, Corey

    2014-01-01

    As tablet technologies continue to evolve, the emergence of educational applications (apps) is impacting the work of teacher educators. Beyond online lists of best apps for education and recommendations from colleagues, teacher educators have few resources available to support their teaching of how to select educational apps. In response, this…

  15. Athletic Training Education: There's an App for That

    ERIC Educational Resources Information Center

    Keeley, Kim; Potteiger, Kelly; Brown, Christopher D.

    2015-01-01

    Context: Mobile applications (apps) are growing in popularity due to the increased use of smartphones. Many available apps are educational in nature and may provide both students and educators freedom for learning to occur outside of the typical classroom environment. Objective: To provide a description of relevant apps along with a brief synopsis…

  16. Car App's Persuasive Design Principles and Behavior Change

    ERIC Educational Resources Information Center

    Zhang, Chao; Wan, Lili; Min, Daihwan

    2016-01-01

    The emphasis of this study lies in behavior change after using car apps that assist users in using their vehicles and establishing a process for examining the interrelationship between car app's persuasive characteristics and behavior change. A categorizing method was developed and 697 car apps were investigated and classified into eight…

  17. Mobile Phone Apps to Improve Medication Adherence: A Systematic Stepwise Process to Identify High-Quality Apps

    PubMed Central

    Richtering, Sarah S; Chalmers, John; Thiagalingam, Aravinda; Chow, Clara K; Redfern, Julie

    2016-01-01

    Background There are a growing number of mobile phone apps available to support people in taking their medications and to improve medication adherence. However, little is known about how these apps differ in terms of features, quality, and effectiveness. Objective We aimed to systematically review the medication reminder apps available in the Australian iTunes store and Google Play to assess their features and their quality in order to identify high-quality apps. Methods This review was conducted in a similar manner to a systematic review by using a stepwise approach that included (1) a search strategy; (2) eligibility assessment; (3) app selection process through an initial screening of all retrieved apps and full app review of the included apps; (4) data extraction using a predefined set of features considered important or desirable in medication reminder apps; (5) analysis by classifying the apps as basic and advanced medication reminder apps and scoring and ranking them; and (6) a quality assessment by using the Mobile App Rating Scale (MARS), a reliable tool to assess mobile health apps. Results We identified 272 medication reminder apps, of which 152 were found only in Google Play, 87 only in iTunes, and 33 in both app stores. Apps found in Google Play had more customer reviews, higher star ratings, and lower cost compared with apps in iTunes. Only 109 apps were available for free and 124 were recently updated in 2015 or 2016. Overall, the median number of features per app was 3.0 (interquartile range 4.0) and only 18 apps had ≥9 of the 17 desirable features. The most common features were flexible scheduling that was present in 56.3% (153/272) of the included apps, medication tracking history in 54.8% (149/272), snooze option in 34.9% (95/272), and visual aids in 32.4% (88/272). We classified 54.8% (149/272) of the included apps as advanced medication reminder apps and 45.2% (123/272) as basic medication reminder apps. The advanced apps had a higher number

  18. APP Deletion Accounts for Age-Dependent Changes in the Bioenergetic Metabolism and in Hyperphosphorylated CaMKII at Stimulated Hippocampal Presynaptic Active Zones

    PubMed Central

    Laßek, Melanie; Weingarten, Jens; Wegner, Martin; Neupärtl, Moritz; Array, Tabiwang N.; Harde, Eva; Beckert, Benedikt; Golghalyani, Vahid; Ackermann, Jörg; Koch, Ina; Müller, Ulrike C.; Karas, Michael; Acker-Palmer, Amparo; Volknandt, Walter

    2017-01-01

    Synaptic release sites are characterized by exocytosis-competent synaptic vesicles tightly anchored to the presynaptic active zone (PAZ) whose proteome orchestrates the fast signaling events involved in synaptic vesicle cycle and plasticity. Allocation of the amyloid precursor protein (APP) to the PAZ proteome implicated a functional impact of APP in neuronal communication. In this study, we combined state-of-the-art proteomics, electrophysiology and bioinformatics to address protein abundance and functional changes at the native hippocampal PAZ in young and old APP-KO mice. We evaluated if APP deletion has an impact on the metabolic activity of presynaptic mitochondria. Furthermore, we quantified differences in the phosphorylation status after long-term-potentiation (LTP) induction at the purified native PAZ. We observed an increase in the phosphorylation of the signaling enzyme calmodulin-dependent kinase II (CaMKII) only in old APP-KO mice. During aging APP deletion is accompanied by a severe decrease in metabolic activity and hyperphosphorylation of CaMKII. This attributes an essential functional role to APP at hippocampal PAZ and putative molecular mechanisms underlying the age-dependent impairments in learning and memory in APP-KO mice. PMID:28163681

  19. APP Deletion Accounts for Age-Dependent Changes in the Bioenergetic Metabolism and in Hyperphosphorylated CaMKII at Stimulated Hippocampal Presynaptic Active Zones.

    PubMed

    Laßek, Melanie; Weingarten, Jens; Wegner, Martin; Neupärtl, Moritz; Array, Tabiwang N; Harde, Eva; Beckert, Benedikt; Golghalyani, Vahid; Ackermann, Jörg; Koch, Ina; Müller, Ulrike C; Karas, Michael; Acker-Palmer, Amparo; Volknandt, Walter

    2017-01-01

    Synaptic release sites are characterized by exocytosis-competent synaptic vesicles tightly anchored to the presynaptic active zone (PAZ) whose proteome orchestrates the fast signaling events involved in synaptic vesicle cycle and plasticity. Allocation of the amyloid precursor protein (APP) to the PAZ proteome implicated a functional impact of APP in neuronal communication. In this study, we combined state-of-the-art proteomics, electrophysiology and bioinformatics to address protein abundance and functional changes at the native hippocampal PAZ in young and old APP-KO mice. We evaluated if APP deletion has an impact on the metabolic activity of presynaptic mitochondria. Furthermore, we quantified differences in the phosphorylation status after long-term-potentiation (LTP) induction at the purified native PAZ. We observed an increase in the phosphorylation of the signaling enzyme calmodulin-dependent kinase II (CaMKII) only in old APP-KO mice. During aging APP deletion is accompanied by a severe decrease in metabolic activity and hyperphosphorylation of CaMKII. This attributes an essential functional role to APP at hippocampal PAZ and putative molecular mechanisms underlying the age-dependent impairments in learning and memory in APP-KO mice.

  20. Smartphone Apps for Schizophrenia: A Systematic Review

    PubMed Central

    2015-01-01

    Background There is increasing interest in using mobile technologies such as smartphones for improving the care of patients with schizophrenia. However, less is known about the current clinical evidence for the feasibility and effectiveness of smartphone apps in this population. Objective To review the published literature of smartphone apps applied for the care of patients with schizophrenia and other psychotic disorders. Methods An electronic database search of Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, Health Technology Assessment Database, Allied and Complementary Medicine, Health and Psychosocial Instruments, PsycINFO, and Embase was conducted on May 24, 2015. All eligible studies were systematically reviewed, and proportional meta-analyses were applied to pooled data on recruitment, retention, and adherence to examine the overall feasibility of smartphone interventions for schizophrenia. Results Our search produced 226 results from which 7 eligible articles were identified, reporting on 5 studies of smartphone apps for patients with schizophrenia. All examined feasibility, and one assessed the preliminary efficacy of a smartphone intervention for schizophrenia. Study lengths varied between 6 and 130 days. Overall retention was 92% (95% CI 82-98%). Participants consistently used the smartphone apps on more than 85% of days during the study period, averaging 3.95 interactions per person per day. Furthermore, participants responded to 71.9% of automated prompts (95% CI 65.7-77.8%). Participants reported a range of potential benefits from the various interventions, and user experience was largely positive. Conclusions Although small, the current published literature demonstrates strong evidence for the feasibility of using smartphones to enhance the care of people with schizophrenia. High rates of engagement and satisfaction with a broad range of apps suggest the nascent potential of this mobile technology. However, there remains limited

  1. Analysis of the subcellular distribution of avian p95-APP2, an ARF-GAP orthologous to mammalian paxillin kinase linker.

    PubMed

    Paris, Simona; Za, Lorena; Sporchia, Barbara; de Curtis, Ivan

    2002-07-01

    We describe here the identification and characterization of avian p95-APP2, a multi-domain protein of a recently identified family of ADP-ribosylation factor (ARF)-GTPase-activating proteins (GAPs) including mammalian G protein-coupled receptor kinases (GRK)-interactor 1 (GIT1), paxillin kinase linker (PKL), and GIT2, as well as avian p95-APP1. The p95-APP2 is eluted from Rac-GTP-gamma-S, but not from Rac-GDP-beta-S columns. As other members of the family, p95-APP2 has binding regions for the focal adhesion protein paxillin, and for the Rac exchanging factor PIX. Sequence comparison indicates that p95-APP2 is the avian orthologue of mammalian PKL. Expression studies showed a largely diffuse distribution of the full length p95-APP2, without evident effects on cell morphology. We observed a dramatic difference between the localization of the amino-terminal portion of the protein, including the ARF-GAP domain and the three ankyrin repeats, and the carboxy-terminal portion including the paxillin-binding site. Moreover, the expression of truncated carboxy-terminal polypeptides including both the PIX- and paxillin-binding regions leads to a marked localization of the protein together with paxillin at large vesicles. Comparison of the expression of corresponding ARF-GAP-deficient constructs from p95-APP2 and p95-APP1 shows their distribution at distinct endocytic compartments. Altogether, these data support a role of distinct members of this family of ARF-GAPs in the regulation of different steps of membrane traffic during cell motility, and suggest that p95-APP2 may shuttle between an intracellular compartment and the cell periphery, although, further work will be needed to address this point.

  2. Effect of the surface charge distribution on the fluid phase behavior of charged colloids and proteins

    NASA Astrophysics Data System (ADS)

    Blanco, Marco A.; Shen, Vincent K.

    2016-10-01

    A generic but simple model is presented to evaluate the effect of the heterogeneous surface charge distribution of proteins and zwitterionic nanoparticles on their thermodynamic phase behavior. By considering surface charges as continuous "patches," the rich set of surface patterns that is embedded in proteins and charged patchy particles can readily be described. This model is used to study the fluid phase separation of charged particles where the screening length is of the same order of magnitude as the particle size. In particular, two types of charged particles are studied: dipolar fluids and protein-like fluids. The former represents the simplest case of zwitterionic particles, whose charge distribution can be described by their dipole moment. The latter system corresponds to molecules/particles with complex surface charge arrangements such as those found in biomolecules. The results for both systems suggest a relation between the critical region, the strength of the interparticle interactions, and the arrangement of charged patches, where the critical temperature is strongly correlated to the magnitude of the dipole moment. Additionally, competition between attractive and repulsive charge-charge interactions seems to be related to the formation of fluctuating clusters in the dilute phase of dipolar fluids, as well as to the broadening of the binodal curve in protein-like fluids. Finally, a variety of self-assembled architectures are detected for dipolar fluids upon small changes to the charge distribution, providing the groundwork for studying the self-assembly of charged patchy particles.

  3. Binary liquid phase separation and critical phenomena in a protein/water solution.

    PubMed Central

    Thomson, J A; Schurtenberger, P; Thurston, G M; Benedek, G B

    1987-01-01

    We have investigated the phase diagram of aqueous solutions of the bovine lens protein gamma II-crystallin. For temperatures T less than Tc = 278.5 K, we find that these solutions exhibit a reversible coexistence between two isotropic liquid phases differing in protein concentration. The dilute and concentrated branches of the coexistence curve were characterized, consistently, both by measurements of the two coexisting concentrations, c(T), and by measuring the cloud temperatures for various initial concentrations. We estimate that the critical concentration, cc, is 244 mg of protein per ml solution. The coexistence curve is well represented by the absolute value of (c - cc)/cc = 5.2 square root (Tc - T)/Tc. Using the temperature dependence of the scattered light intensity along isochores parallel to the critical isochore, we estimated the location of the spinodal line and found it to have the form (c - cc)/cc = 3.0 square root (Tc - T)/Tc. The ratio of the widths of the coexistence curve and the spinodal line, (5.2/3.0), is close to the mean-field value square root 3. We have also observed the growth of large crystals of gamma II-crystallin in some of these aqueous solutions and have made preliminary observations as to the factors that promote or delay the onset of crystallization. These findings suggest that selected protein/water systems can serve as excellent model systems for the study of phase transitions and critical phenomena. PMID:3478681

  4. Phase behaviour and in vitro hydrolysis of wheat starch in mixture with whey protein.

    PubMed

    Yang, Natasha; Liu, Yingting; Ashton, John; Gorczyca, Elisabeth; Kasapis, Stefan

    2013-04-15

    Network formation of whey protein isolate (WPI) with increasing concentrations of native wheat starch (WS) has been examined. Small deformation dynamic oscillation in shear and modulated temperature differential scanning calorimetry enabled analysis of binary mixtures at the macro- and micromolecular level. Following heat induced gelation, textural hardness was measured by undertaking compression tests. Environmental scanning electron microscopy provided tangible information on network morphology of polymeric constituents. Experiments involving in vitro starch digestion also allowed for indirect assessment of phase topology in the binary mixture. The biochemical component of this work constitutes an attempt to utilise whey protein as a retardant to the enzymatic hydrolysis of starch in a model system with α-amylase enzyme. During heating, rheological profiles of binary mixtures exhibited dramatic increases in G' at temperatures more closely related to those observed for single whey protein rather than pure starch. Results from this multidisciplinary approach of analysis, utilising rheology, calorimetry and microscopy, argue for the occurrence of phase separation phenomena in the gelled systems. There is also evidence of whey protein forming the continuous phase with wheat starch being the discontinuous filler, an outcome that is explored in the in vitro study of the enzymatic hydrolysis of starch.

  5. Observation of Structural Phase Transition in Ferroelectric Crystals Using Green Fluorescence Protein

    NASA Astrophysics Data System (ADS)

    Sedarous, Salah; Wessels, William

    1998-03-01

    The Green Fluorescence Protein (GFP) of the jellyfish Aequorea Victoria has attracted widespread interest as a biomolecular marker. It has created many applications in a variety of systems ranging from cell biology to biomedicine. One important application of GFP fluorescence is the detection of structural transitions in biomolecules.In order to examine the sensitivity of the protein fluorescence to structural changes, we sequestered GFP in ferroelectric crystals such as Triglycine sulfate (TGS) and Rochelle salt (RS). TGS has a second order phase transition at 49 C while RS has two phase transitions at -18 and +24 C. The peak of the fluorescence spectrum changes from 510 nm in solution to 470 nm in the crystal indicating a shift of the two absorption bands in the protein upon crystallization. The fluorescence intensity of GFP in TGS decreases as the temperature of the crystal approaches T_C, while its spectrum in RS shows complex changes with temperature. The changes in the time-resolved data are similar to that of the steady state data. Our data show that the onset of structural phase transition in these crystals is clearly detectable from the spectral changes of this chromophore. Other applications of this protein in time-resolved solid state dynamics will be discussed.

  6. Responsive Gel-Gel Phase Transitions in Artificially Engineered Protein Hydrogels

    NASA Astrophysics Data System (ADS)

    Olsen, B. D.

    2012-02-01

    Artificially engineered protein hydrogels provide an attractive platform for biomedical materials due to their similarity to components of the native extracellular matrix. Engineering responsive transitions between shear-thinning and tough gel phases in these materials could potentially enable gels that are both shear-thinning and tough to be produced as novel injectable biomaterials. To engineer a gel with such transitions, a triblock copolymer with thermoresponsive polymer endblocks and an artificially engineered protein gel midblock is designed. Temperature is used to trigger a transition from a single network protein hydrogel phase to a double network phase with both protein and block copolymer networks present at different length scales. The thermodynamics of network formation and resulting structural changes are established using small-angle scattering, birefringence, and dynamic scanning calorimetry. The formation of the second network is shown to produce a large, nonlinear increase in the elastic modulus as well as enhancements in creep compliance and toughness. Although the gels show yielding behavior in both the single and double network regimes, a qualitative change in the deformation mechanism is observed due to the structural changes.

  7. Renaturing Membrane Proteins in the Lipid Cubic Phase, a Nanoporous Membrane Mimetic

    PubMed Central

    Li, Dianfan; Caffrey, Martin

    2014-01-01

    Membrane proteins play vital roles in the life of the cell and are important therapeutic targets. Producing them in large quantities, pure and fully functional is a major challenge. Many promising projects end when intractable aggregates or precipitates form. Here we show how such unfolded aggregates can be solubilized and the solution mixed with lipid to spontaneously self-assemble a bicontinuous cubic mesophase into the bilayer of which the protein, in a confined, chaperonin-like environment, reconstitutes with 100% efficiency. The test protein, diacylglycerol kinase, reconstituted in the bilayer of the mesophase, was then crystallized in situ by the in meso or lipid cubic phase method providing an X-ray structure to a resolution of 2.55 Å. This highly efficient, inexpensive, simple and rapid approach should find application wherever properly folded, membrane reconstituted and functional proteins are required where the starting material is a denatured aggregate. PMID:25055873

  8. Amphipols Outperform Dodecylmaltoside Micelles in Stabilizing Membrane Protein Structure in the Gas Phase

    PubMed Central

    2014-01-01

    Noncovalent mass spectrometry (MS) is emerging as an invaluable technique to probe the structure, interactions, and dynamics of membrane proteins (MPs). However, maintaining native-like MP conformations in the gas phase using detergent solubilized proteins is often challenging and may limit structural analysis. Amphipols, such as the well characterized A8-35, are alternative reagents able to maintain the solubility of MPs in detergent-free solution. In this work, the ability of A8-35 to retain the structural integrity of MPs for interrogation by electrospray ionization-ion mobility spectrometry-mass spectrometry (ESI-IMS-MS) is compared systematically with the commonly used detergent dodecylmaltoside. MPs from the two major structural classes were selected for analysis, including two β-barrel outer MPs, PagP and OmpT (20.2 and 33.5 kDa, respectively), and two α-helical proteins, Mhp1 and GalP (54.6 and 51.7 kDa, respectively). Evaluation of the rotationally averaged collision cross sections of the observed ions revealed that the native structures of detergent solubilized MPs were not always retained in the gas phase, with both collapsed and unfolded species being detected. In contrast, ESI-IMS-MS analysis of the amphipol solubilized MPs studied resulted in charge state distributions consistent with less gas phase induced unfolding, and the presence of lowly charged ions which exhibit collision cross sections comparable with those calculated from high resolution structural data. The data demonstrate that A8-35 can be more effective than dodecylmaltoside at maintaining native MP structure and interactions in the gas phase, permitting noncovalent ESI-IMS-MS analysis of MPs from the two major structural classes, while gas phase dissociation from dodecylmaltoside micelles leads to significant gas phase unfolding, especially for the α-helical MPs studied. PMID:25495802

  9. Restriction of histone gene transcription to S phase by phosphorylation of a chromatin boundary protein

    PubMed Central

    Kurat, Christoph F.; Lambert, Jean-Philippe; van Dyk, Dewald; Tsui, Kyle; van Bakel, Harm; Kaluarachchi, Supipi; Friesen, Helena; Kainth, Pinay; Nislow, Corey; Figeys, Daniel; Fillingham, Jeffrey; Andrews, Brenda J.

    2011-01-01

    The cell cycle-regulated expression of core histone genes is required for DNA replication and proper cell cycle progression in eukaryotic cells. Although some factors involved in histone gene transcription are known, the molecular mechanisms that ensure proper induction of histone gene expression during S phase remain enigmatic. Here we demonstrate that S-phase transcription of the model histone gene HTA1 in yeast is regulated by a novel attach–release mechanism involving phosphorylation of the conserved chromatin boundary protein Yta7 by both cyclin-dependent kinase 1 (Cdk1) and casein kinase 2 (CK2). Outside S phase, integrity of the AAA-ATPase domain is required for Yta7 boundary function, as defined by correct positioning of the histone chaperone Rtt106 and the chromatin remodeling complex RSC. Conversely, in S phase, Yta7 is hyperphosphorylated, causing its release from HTA1 chromatin and productive transcription. Most importantly, abrogation of Yta7 phosphorylation results in constitutive attachment of Yta7 to HTA1 chromatin, preventing efficient transcription post-recruitment of RNA polymerase II (RNAPII). Our study identified the chromatin boundary protein Yta7 as a key regulator that links S-phase kinases with RNAPII function at cell cycle-regulated histone gene promoters. PMID:22156209

  10. Restriction of histone gene transcription to S phase by phosphorylation of a chromatin boundary protein.

    PubMed

    Kurat, Christoph F; Lambert, Jean-Philippe; van Dyk, Dewald; Tsui, Kyle; van Bakel, Harm; Kaluarachchi, Supipi; Friesen, Helena; Kainth, Pinay; Nislow, Corey; Figeys, Daniel; Fillingham, Jeffrey; Andrews, Brenda J

    2011-12-01

    The cell cycle-regulated expression of core histone genes is required for DNA replication and proper cell cycle progression in eukaryotic cells. Although some factors involved in histone gene transcription are known, the molecular mechanisms that ensure proper induction of histone gene expression during S phase remain enigmatic. Here we demonstrate that S-phase transcription of the model histone gene HTA1 in yeast is regulated by a novel attach-release mechanism involving phosphorylation of the conserved chromatin boundary protein Yta7 by both cyclin-dependent kinase 1 (Cdk1) and casein kinase 2 (CK2). Outside S phase, integrity of the AAA-ATPase domain is required for Yta7 boundary function, as defined by correct positioning of the histone chaperone Rtt106 and the chromatin remodeling complex RSC. Conversely, in S phase, Yta7 is hyperphosphorylated, causing its release from HTA1 chromatin and productive transcription. Most importantly, abrogation of Yta7 phosphorylation results in constitutive attachment of Yta7 to HTA1 chromatin, preventing efficient transcription post-recruitment of RNA polymerase II (RNAPII). Our study identified the chromatin boundary protein Yta7 as a key regulator that links S-phase kinases with RNAPII function at cell cycle-regulated histone gene promoters.

  11. Global Analysis of S-nitrosylation Sites in the Wild Type (APP) Transgenic Mouse Brain-Clues for Synaptic Pathology *

    PubMed Central

    Zaręba-Kozioł, Monika; Szwajda, Agnieszka; Dadlez, Michał; Wysłouch-Cieszyńska, Aleksandra; Lalowski, Maciej

    2014-01-01

    Alzheimer's disease (AD) is characterized by an early synaptic loss, which strongly correlates with the severity of dementia. The pathogenesis and causes of characteristic AD symptoms are not fully understood. Defects in various cellular cascades were suggested, including the imbalance in production of reactive oxygen and nitrogen species. Alterations in S-nitrosylation of several proteins were previously demonstrated in various AD animal models and patients. In this work, using combined biotin-switch affinity/nano-LC-MS/MS and bioinformatic approaches we profiled endogenous S-nitrosylation of brain synaptosomal proteins from wild type and transgenic mice overexpressing mutated human Amyloid Precursor Protein (hAPP). Our data suggest involvement of S-nitrosylation in the regulation of 138 synaptic proteins, including MAGUK, CamkII, or synaptotagmins. Thirty-eight proteins were differentially S-nitrosylated in hAPP mice only. Ninety-five S-nitrosylated peptides were identified for the first time (40% of total, including 33 peptides exclusively in hAPP synaptosomes). We verified differential S-nitrosylation of 10 (26% of all identified) synaptosomal proteins from hAPP mice, by Western blotting with specific antibodies. Functional enrichment analysis linked S-nitrosylated proteins to various cellular pathways, including: glycolysis, gluconeogenesis, calcium homeostasis, ion, and vesicle transport, suggesting a basic role of this post-translational modification in the regulation of synapses. The linkage of SNO-proteins to axonal guidance and other processes related to APP metabolism exclusively in the hAPP brain, implicates S-nitrosylation in the pathogenesis of Alzheimer's disease. PMID:24895380

  12. An over expression APP model for anti-Alzheimer disease drug screening created by zinc finger nuclease technology.

    PubMed

    Zhang, Xiaojing; Li, Hui; Mao, Yiqing; Li, Zhixin; Wang, Rong; Guo, Tingting; Jin, Ling; Song, Rongjing; Xu, Wei; Zhou, Na; Zhang, Yizhuang; Hu, Ruobi; Wang, Xi; Huang, Huakang; Lei, Zhen; Niu, Gang; Irwin, David M; Tan, Huanran

    2013-01-01

    Zinc Finger Nucleases (ZFNs), famous for their ability to precisely and efficiently modify specific genomic loci, have been employed in numerous transgenic model organism and cell constructions. Here we employ the ZFNs technology, with homologous recombination (HR), to construct sequence-specific Amyloid Precursor Protein (APP) knock-in cells. With the use of ZFNs, we established APP knock in cell lines with gene-modification efficiencies of about 7%. We electroporated DNA fragment containing the promoter and the protein coding regions of the zinc finger nucleases into cells, instead of the plasmids, to avoid problems associated with off target homologous recombination, and adopted a pair of mutated FokI cleavage domains to reduce the toxic effects of the ZFNs on cell growth. Since over-expression of APP, or a subdomain of it, might lead to an immediately lethal effect, we used the Cre-LoxP System to regulate APP expression. Our genetically transformed cell lines, w5c1 and s12c8, showed detectable APP and Amyloid β (Aβ) production. The Swedish double mutation in the APP coding sequence enhanced APP and Aβ abundance. What is more, the activity of the three key secretases in Aβ formation could be modulated, indicating that these transgenic cells have potential for drug screening to modify amyloid metabolism in cells. Our transformed cells could readily be propagated in culture and should provide an excellent experimental medium for elucidating aspects of the molecular pathogenesis of Alzheimer's disease, especially those concerning the amyloidogenic pathways involving mutations in the APP coding sequence. The cellular models may also serve as a tool for deriving potentially useful therapeutic agents.

  13. Protein synthesis during the initial phase of the temperature-induced bleaching response in Euglena gracilis

    SciTech Connect

    Ortiz, W. )

    1990-05-01

    Growing cultures of photoheterotrophic Euglena gracilis experience an increase in chlorophyll accumulation during the initial phase of the temperature-induced bleaching response suggesting an increase in the synthesis of plastid components at the bleaching temperature of 33{degree}C. A primary goal of this work was to establish whether an increase in the synthesis of plastid proteins accompanies the observed increase in chlorophyll accumulation. In vivo pulse-labeling experiments with ({sup 35}S)sodium sulfate were carried out with cells grown at room temperature or at 33{degree}C. The synthesis of a number of plastid polypeptides of nucleocytoplasmic origin, including some presumably novel polypeptides, increased in cultures treated for 15 hours at 33{degree}C. In contrast, while synthesis of thylakoid proteins by the plastid protein synthesis machinery decreased modestly, synthesis of the large subunit of the enzyme ribulosebisphosphate carboxylase was strongly affected at the elevated temperature. Synthesis of novel plastid-encoded polypeptides was not induced at the bleaching temperature. It is concluded that protein synthesis in plastids declines during the initial phase of the temperature response in Euglena despite an overall increase in cellular protein synthesis and an increase in chlorophyll accumulation per cell.

  14. Apps and eating disorders: A systematic clinical appraisal

    PubMed Central

    Rothwell, Emily R.

    2015-01-01

    ABSTRACT Objective Smartphone applications (apps) are proliferating and health‐related apps are particularly popular. The aim of this study was to identify, characterize, and evaluate the clinical utility of apps designed either for people with eating disorders or for eating disorder professionals. Method A search of the major app stores identified 805 potentially relevant apps, of which 39 were primarily designed for people with eating disorders and five for professionals. Results The apps for people with eating disorders had four main functions. Most common was the provision of advice, the quality of which ranged from sound to potentially harmful. Five apps included self‐assessment tools but only two used methods that would generally be viewed as reliable. Four apps had the self‐monitoring of eating habits as a major feature. Entering information into these apps could be accomplished with varying degrees of ease, but viewing it was more difficult. One app allowed the transfer of information between patients and clinicians. Discussion The enthusiasm for apps outstrips the evidence supporting their use. Given their popularity, it is suggested that clinicians evaluate app use as part of routine assessment. The clinical utility of the existing apps is not clear. Some are capable of tracking key features over time, but none has the functions required for analytic self‐monitoring as in cognitive behavioral treatments. The full potential of apps has yet to be realized. Specialized apps could be designed to augment various forms of treatment, and there is the possibility that they could deliver an entire personalized intervention. © 2015 The Authors. International Journal of Eating Disorders published by Wiley Periodicals, Inc. (Int J Eat Disord 2015; 48:1038–1046) PMID:25728705

  15. The circular RNA ciRS-7 promotes APP and BACE1 degradation in an NF-κB-dependent manner.

    PubMed

    Shi, Zhemin; Chen, Ting; Yao, Qingbin; Zheng, Lina; Zhang, Zhen; Wang, Jingzhao; Hu, Zhimei; Cui, Hongmei; Han, Yawei; Han, Xiaohui; Zhang, Kun; Hong, Wei

    2017-04-01

    The aberrant accumulation of β-amyloid peptide (Aβ) in the brain is a key feature of Alzheimer's disease (AD), and enhanced cleavage of β-amyloid precursor protein (APP) by β-site APP-cleaving enzyme 1 (BACE1) has a major causative role in AD. Despite their prominence in AD pathogenesis, the regulation of BACE1 and APP is incompletely understood. In this study, we report that the circular RNA circular RNA sponge for miR-7 (ciRS-7) has an important role in regulating BACE1 and APP protein levels. Previous studies have shown that ciRS-7, which is highly expressed in the human brain, is down-regulated in the brain of people with AD but the relevance of this finding was not clear. We have found that ciRS-7 is not involved in the regulation of APP and BACE1 gene expression, but instead reduces the protein levels of APP and BACE1 by promoting their degradation via the proteasome and lysosome. Consequently, overexpression of ciRS-7 reduces the generation of Aβ, indicating a potential neuroprotective role of ciRS-7. Our data also suggest that ciRS-7 modulates APP and BACE1 levels in a nuclear factor-κB (NF-κB)-dependent manner: ciRS-7 expression inhibits translation of NF-κB and induces its cytoplasmic localization, thus derepressing expression of UCHL1, which promotes APP and BACE1 degradation. Additionally, we demonstrated that APP reduces the level of ciRS-7, revealing a mutual regulation of ciRS-7 and APP. Taken together, our data provide a molecular mechanism implicating reduced ciRS-7 expression in AD, suggesting that ciRS-7 may represent a useful target in the development of therapeutic strategies for AD.

  16. Growth-Phase-Specific Modulation of Cell Morphology and Gene Expression by an Archaeal Histone Protein

    PubMed Central

    Dulmage, Keely A.; Todor, Horia

    2015-01-01

    ABSTRACT In all three domains of life, organisms use nonspecific DNA-binding proteins to compact and organize the genome as well as to regulate transcription on a global scale. Histone is the primary eukaryotic nucleoprotein, and its evolutionary roots can be traced to the archaea. However, not all archaea use this protein as the primary DNA-packaging component, raising questions regarding the role of histones in archaeal chromatin function. Here, quantitative phenotyping, transcriptomic, and proteomic assays were performed on deletion and overexpression mutants of the sole histone protein of the hypersaline-adapted haloarchaeal model organism Halobacterium salinarum. This protein is highly conserved among all sequenced haloarchaeal species and maintains hallmark residues required for eukaryotic histone functions. Surprisingly, despite this conservation at the sequence level, unlike in other archaea or eukaryotes, H. salinarum histone is required to regulate cell shape but is not necessary for survival. Genome-wide expression changes in histone deletion strains were global, significant but subtle in terms of fold change, bidirectional, and growth phase dependent. Mass spectrometric proteomic identification of proteins from chromatin enrichments yielded levels of histone and putative nucleoid-associated proteins similar to those of transcription factors, consistent with an open and transcriptionally active genome. Taken together, these data suggest that histone in H. salinarum plays a minor role in DNA compaction but important roles in growth-phase-dependent gene expression and regulation of cell shape. Histone function in haloarchaea more closely resembles a regulator of gene expression than a chromatin-organizing protein like canonical eukaryotic histone. PMID:26350964

  17. Evaluation and comparison of n-alkyl chain and polar ligand bonded stationary phases for protein separation in reversed-phase liquid chromatography.

    PubMed

    Ding, Ling; Guo, Zhimou; Xiao, Yuansheng; Xue, Xingya; Zhang, Xiuli; Liang, Xinmiao

    2014-09-01

    Protein retention is very sensitive to the change of solvent composition in reversed-phase liquid chromatography for so called "on-off" mechanism, leading to difficulty in mobile phase optimization. In this study, a novel 3-chloropropyl trichlorosilane ligand bonded column was prepared for protein separation. The differences in retention characteristics between the 3-chloropropyl trichlorosilane ligand bonded column and n-alkyl chain modified (C2, C4, C8) stationary phases were elucidated by the retention equation l nk=a+cC(B). Retention parameters (a and c) of nine standard proteins with different molecular weights were calculated by using homemade software. Results showed that retention times of nine proteins were similar on four columns, but the 3-chloropropyl trichlorosilane ligand bonded column obtained the lowest retention parameter values of larger proteins. It meant that their retention behavior affected by acetonitrile concentration would be different due to lower |c| values. More specifically, protein elution windows were broader, and retentions were less sensitive to the change of acetonitrile concentration on the 3-chloropropyl trichlorosilane ligand bonded column than that on other columns. Meanwhile, the 3-chloropropyl trichlorosilane ligand bonded column displayed distinctive selectivity for some proteins. Our results indicated that stationary phase with polar ligand provided potential solutions to the "on-off" problem and optimization in protein separation.

  18. Apps for People With Rheumatoid Arthritis to Monitor Their Disease Activity: A Review of Apps for Best Practice and Quality

    PubMed Central

    Townsley, Hermaleigh; White, Bonnie; Langlotz, Tobias; Taylor, William J

    2017-01-01

    Background Rheumatoid arthritis (RA) is a chronic inflammatory arthritis requiring long-term treatment with regular monitoring by a rheumatologist to achieve good health outcomes. Since people with RA may wish to monitor their own disease activity with a smartphone app, it is important to understand the functions and quality of apps for this purpose. Objective The aim of our study was to assess the features and quality of apps to assist people to monitor their RA disease activity by (1) summarizing the available apps, particularly the instruments used for measurement of RA disease activity; (2) comparing the app features with American College of Rheumatology and European League against Rheumatism (ACR and EULAR) guidelines for monitoring of RA disease activity; and (3) rating app quality with the Mobile App Rating Scale (MARS). Methods Systematic searches of the New Zealand iTunes and Google Play app stores were used to identify all apps for monitoring of RA disease activity that could be used by people with RA. The apps were described by both key metadata and app functionality. App adherence with recommendations for monitoring of RA disease activity in clinical practice was evaluated by identifying whether apps included calculation of a validated composite disease activity measure and recorded results for future retrieval. App quality was assessed by 2 independent reviewers using the MARS. Results The search identified 721 apps in the Google Play store and 216 in the iTunes store, of which 19 unique apps met criteria for inclusion (8 from both app stores, 8 iTunes, and 3 Google Play). In total, 14 apps included at least one validated instrument measuring RA disease activity; 7 of 11 apps that allowed users to enter a joint count used the standard 28 swollen and tender joint count; 8 apps included at least one ACR and EULAR-recommended RA composite disease activity (CDA) measure; and 10 apps included data storage and retrieval. Only 1 app, Arthritis Power, included

  19. Osthole Upregulates BDNF to Enhance Adult Hippocampal Neurogenesis in APP/PS1 Transgenic Mice.

    PubMed

    Liu, Hong; Xue, Xinhong; Shi, Huijian; Qi, Lifeng; Gong, Dianrong

    2015-01-01

    Adult hippocampal neurogenesis occurs in the dentate gyrus (DG) of the mouse hippocampus, and plays roles in learning and memory progresses. In amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic mice, a rodent model of Alzheimer's disease (AD), severe impairment of neurogenesis in the dentate subgranular zone (SGZ) of the DG has been reported. Osthole, an active constituent of Cnidium monnieri (L.) CUSSON, has been reported to exert neuroprotective effects and may promote neural stem cell proliferation. However, whether osthole ameliorates spatial memory deficits and improves hippocampal neurogenesis in APP/PS1 mice remains unknown. In this study we found that osthole (30 mg/kg intraperitoneally (i.p.) once daily) treatment dramatically ameliorated the cognitive impairments by Morris Water Maze test and passive avoidance test, and augmented neurogenesis in the DG of hippocampus in APP/PS1 mice. Furthermore, osthole treatment upregulated expression of brain-derived neurotrophic factor (BDNF) and enhanced activation of the BDNF receptor tyrosine receptor kinase B (TrkB) following increased phosphorylation of cyclic AMP response element-binding protein (CREB), indicating that osthole improves neurogenesis via stimulating BDNF/TrkB/CREB signaling in APP/PS1 transgenic mice.

  20. Aβ aggregation profiles and shifts in APP processing favor amyloidogenesis in canines

    PubMed Central

    Pop, Viorela; Head, Elizabeth; Berchtold, Nicole C.; Glabe, Charles G.; Studzinski, Christa M.; Weidner, Adam M.; Murphy, M. Paul; Cotman, Carl W.

    2010-01-01

    The aged canine is a higher animal model that naturally accumulates β-amyloid (Aβ) and shows age-related cognitive decline. However, profiles of Aβ accumulation in different species (40 vs. 42), its assembly states, and Aβ precursor protein (APP) processing as a function of age remain unexplored. In this study, we show that Aβ increases progressively with age as detected in extracellular plaques and biochemically extractable Aβ40 and Aβ42 species. Soluble oligomeric forms of the peptide, with specific increases in an Aβ oligomer migrating at 56kDa, also increase with age. Changes in APP processing could potentially explain why Aβ accumulates, and we show age-related shifts towards decreased total APP protein and non-amyloidogenic (α-secretase) processing coupled with increased amyloidogenic (β-secretase) cleavage of APP. Importantly, we describe Aβ pathology in the cingulate and temporal cortex and provide a description of oligomeric Aβ across the canine lifespan. Our findings are in line with observations in the human brain, suggesting that canines are a valuable higher animal model for the study of Aβ pathogenesis. PMID:20434811

  1. Application of the aqueous two-phase systems of ethylene and propylene oxide copolymer-maltodextrin for protein purification.

    PubMed

    Bolognese, Belén; Nerli, Bibiana; Picó, Guillermo

    2005-01-25

    In this study, the effect of several factors that govern the partitioning behaviour of three model proteins, such as bovine serum albumin, lysozyme and trypsin was analysed in a two-phase system formed by maltodextrin and a copolymer of ethylene and propylene oxides. The protein partition coefficient (K(r)) showed to be very sensitive to temperature changes, protein molecular weight, pH medium and the lyotropic ion presence. The phase diagram obtained for these novel polymer-polymer two-phase systems shows two phases with high polymer concentrations. The maltodextrin is enriched in the bottom phase while the copolymer of ethylene and propylene oxides is found in the upper phase. Since this copolymer is thermoreactive, the upper phase can be removed and heated above the copolymer's cloud point resulting in the formation of a new two-phase system with a lower water phase, containing the target protein and an upper copolymer-rich phase. Our results show that systems formed by maltodextrin and a copolymer of ethylene and propylene oxides may be considered as an interesting alternative to be used in protein purification due to their low cost, and also because they offer a viable solution to problems of polymer removal and recycling.

  2. Native biomolecules in the gas phase? The case of green fluorescent protein.

    PubMed

    Frankevich, Vladimir; Barylyuk, Konstantin; Chingin, Konstantin; Nieckarz, Robert; Zenobi, Renato

    2013-04-02

    Green fluorescent protein (GFP) was ionized by native electrospray ionization and trapped for many seconds in high vacuum, allowing fluorescence emission to be measured as a probe of its biological function, to answer the question whether GFP exists in the native form in the gas phase or not. Although a narrow charge-state distribution, a collision cross-section very close to that expected for correctly folded GFP, and a large stability against dissociation all support a near-native gas-phase structure, no fluorescence emission was observed. The loss of the native form is attributed to the absence of residual water in the gas phase, which normally stabilizes the para-hydroxybenzylidene imidazolone chromophore of GFP.

  3. ADP-2Ho as a Phasing Tool for Nucleotide-Containing Proteins

    SciTech Connect

    Ku,S.; Smith, G.; Howell, P.

    2007-01-01

    Trivalent holmium ions were shown to isomorphously replace magnesium ions to form an ADP-2Ho complex in the nucleotide-binding domain of Bacillus subtilis 5-methylthioribose (MTR) kinase. This nucleotide-holmium complex provided sufficient phasing power to allow SAD and SIRAS phasing of this previously unknown structure using the L{sub III} absorption edge of holmium. The structure of ADP-2Ho reveals that the two Ho ions are approximately 4 {angstrom} apart and are likely to share their ligands: the phosphoryl O atoms of ADP and a water molecule. The structure determination of MTR kinase using data collected using Cu K X-radiation was also attempted. Although the heavy-atom substructure determination was successful, interpretation of the map was more challenging. The isomorphous substitution of holmium for magnesium in the MTR kinase-nucleotide complex suggests that this could be a useful phasing tool for other metal-dependent nucleotide-containing proteins.

  4. Acoustic Methods to Monitor Protein Crystallization and to Detect Protein Crystals in Suspensions of Agarose and Lipidic Cubic Phase.

    PubMed

    Ericson, Daniel L; Yin, Xingyu; Scalia, Alexander; Samara, Yasmin N; Stearns, Richard; Vlahos, Harry; Ellson, Richard; Sweet, Robert M; Soares, Alexei S

    2016-02-01

    Improvements needed for automated crystallography include crystal detection and crystal harvesting. A technique that uses acoustic droplet ejection to harvest crystals was previously reported. Here a method is described for using the same acoustic instrument to detect protein crystals and to monitor crystal growth. Acoustic pulses were used to monitor the progress of crystallization trials and to detect the presence and location of protein crystals. Crystals were detected, and crystallization was monitored in aqueous solutions and in lipidic cubic phase. Using a commercially available acoustic instrument, crystals measuring ~150 µm or larger were readily detected. Simple laboratory techniques were used to increase the sensitivity to 50 µm by suspending the crystals away from the plastic surface of the crystallization plate. This increased the sensitivity by separating the strong signal generated by the plate bottom that can mask the signal from small protein crystals. It is possible to further boost the acoustic reflection from small crystals by reducing the wavelength of the incident sound pulse, but our current instrumentation does not allow this option. In the future, commercially available sound-emitting transducers with a characteristic frequency near 300 MHz should detect and monitor the growth of individual 3 µm crystals.

  5. Elimination Half-Lives of Acute Phase Proteins in Rats and Beagle Dogs During Acute Inflammation.

    PubMed

    Kuribayashi, Takashi; Seita, Tetsuro; Momotani, Eiichi; Yamazaki, Shunsuke; Hagimori, Kohei; Yamamoto, Shizuo

    2015-08-01

    The half-lives of typical acute phase proteins in rats and beagle dogs during acute inflammation were investigated. Acute inflammation was induced by injection of turpentine oil in rats and administration of indomethacin in beagle dogs. Serum concentrations of α2-macroglobulin (α2M) and C-reactive protein (CRP) were measured by enzyme-linked immunosorbent assay and α1-acid glycoprotein (AAG) was measured by single radial immunodiffusion. Half-life was calculated as 0.693/elimination rate constant (K). The mean half-lives in the terminal elimination phase of α2M and AAG were 68.1 and 164.8 h, respectively. The half-life of AAG was significantly longer than that of α2M. Mean half-lives in the terminal elimination phase of CRP and AAG were 161.9 and 304.4 h, respectively. The half-life of AAG was significantly longer than that of CRP in beagle dogs. No significant differences in the half-life of AAG were observed between rats and beagle dogs. Furthermore, serum concentrations in the terminal elimination phase could be simulated with the K data acquired in this study.

  6. C-reactive protein and the acute phase reaction in geriatric patients.

    PubMed

    Bertsch, Thomas; Triebel, Jakob; Bollheimer, Cornelius; Christ, Michael; Sieber, Cornel; Fassbender, Klaus; Heppner, Hans Jürgen

    2015-10-01

    The C-reactive protein (CRP), first described as a serum component capable of precipitating the C-polysaccharide of pneumococci, is one of the most important proteins because the serum concentration rises in the acute phase reaction. The acute phase reaction is the nonspecific reaction of the body to noxious stimuli of the most varied kinds, such as infections, burns, neoplasms and tissue trauma. The CRP is synthesized in liver parenchymal cells by cytokines which are derived from stimulated leucocytes and released into the circulation. Because of its molecular structure and in synergy with the complement system, it is able to precipitate and/or lyse microorganisms, thereby rendering them harmless. Measurement of the serum CRP concentration can provide important information with respect to the diagnosis and monitoring of treatment. Due to immunosenescence in geriatric patients the synthesis of CRP appears to be limited to inflammatory stimuli; however, this phenomenon does not appear to be of major clinical relevance. Despite the introduction of new parameters of the acute phase reaction, sometimes with better performance, such as interleukin-6, procalcitonin and the soluble endotoxin receptor sCD14, measurement of CRP for diagnosis and treatment monitoring is still justified even in geriatric patients as testing is rapid, economic and nearly ubiquitously available round the clock. Biochemical markers of the acute phase reaction should always be interpreted together with the clinical picture and their specific limitations.

  7. Mapping Liquid-liquid protein phase separation using ultra-fast-scanning fluorescence correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Wei, Ming-Tzo; Elbaum-Garfinkle, Shana; Arnold, Craig B.; Priestley, Rodney D.; Brangwynne, Clifford P.

    Intrinsically disordered proteins (IDPs) are an understudied class of proteins that play important roles in a wide variety of biological processes in cells. We've previously shown that the C. elegans IDP LAF-1 phase separates into P granule-like droplets in vitro. However, the physics of the condensed phase remains poorly understood. Here, we use a novel technique, ultra-fast-scanning fluorescence correlation spectroscopy, to study the nano-scale rheological properties of LAF-1 droplets. Ultra-fast-scanning FCS uses a tunable acoustic gradient index of refraction (TAG) lens with an oil immersion objective to control axial movement of the focal point over a length of several micrometers at frequencies of 70kHz. Using ultra-fast-scanning FCS allows for the accurate determination of molecular concentrations and their diffusion coefficient, when the particle is passing through an excitation volume. Our work reveals an asymmetric LAF-1 phase diagram, and demonstrates that LAF-1 droplets are purely viscous phases which are highly tunable by salt concentration.

  8. Improved binding of acidic bone matrix proteins to cationized filters during solid phase assays.

    PubMed

    Farach-Carson, M C; Wright, G C; Butler, W T

    1992-01-01

    A number of commercially available matrix filter supports have been designed for the immobilization of proteins following either electrotransfer from sodium dodecyl sulfate (SDS) polyacrylamide gels or direct application during dot blotting assays. These matrices differ with respect to chemical composition, charge, pore size, and degree of hydrophobicity. It follows that the properties of the protein(s) of interest will greatly influence the degree to which they interact with and ultimately bind to various filters. Acidic bone proteins contain diverse post-translational modifications that influence their interactions with solid phase matrices such as those used in immunoblotting (Western or dot blotting) or ion binding (overlay) procedures. This communication describes the results of a study comparing binding of various mixtures of non-collagenous acidic bone matrix phosphoproteins as well as purified osteopontin and osteocalcin to various filters including nitrocellulose and cationized paper or nylon. Based on our findings, we recommend the use of cationized filters for solid phase assays requiring the binding of these acidic macromolecules to background supports.

  9. Nebula/DSCR1 upregulation delays neurodegeneration and protects against APP-induced axonal transport defects by restoring calcineurin and GSK-3β signaling.

    PubMed

    Shaw, Jillian L; Chang, Karen T

    2013-01-01

    Post-mortem brains from Down syndrome (DS) and Alzheimer's disease (AD) patients show an upregulation of the Down syndrome critical region 1 protein (DSCR1), but its contribution to AD is not known. To gain insights into the role of DSCR1 in AD, we explored the functional interaction between DSCR1 and the amyloid precursor protein (APP), which is known to cause AD when duplicated or upregulated in DS. We find that the Drosophila homolog of DSCR1, Nebula, delays neurodegeneration and ameliorates axonal transport defects caused by APP overexpression. Live-imaging reveals that Nebula facilitates the transport of synaptic proteins and mitochondria affected by APP upregulation. Furthermore, we show that Nebula upregulation protects against axonal transport defects by restoring calcineurin and GSK-3β signaling altered by APP overexpression, thereby preserving cargo-motor interactions. As impaired transport of essential organelles caused by APP perturbation is thought to be an underlying cause of synaptic failure and neurodegeneration in AD, our findings imply that correcting calcineurin and GSK-3β signaling can prevent APP-induced pathologies. Our data further suggest that upregulation of Nebula/DSCR1 is neuroprotective in the presence of APP upregulation and provides evidence for calcineurin inhibition as a novel target for therapeutic intervention in preventing axonal transport impairments associated with AD.

  10. Expression of B4GALNT1, an essential glycosyltransferase for the synthesis of complex gangliosides, suppresses BACE1 degradation and modulates APP processing

    PubMed Central

    Yamaguchi, Tokiaki; Yamauchi, Yoshio; Furukawa, Keiko; Ohmi, Yuhsuke; Ohkawa, Yuki; Zhang, Qing; Okajima, Tetsuya; Furukawa, Koichi

    2016-01-01

    Alzheimer’s disease (AD) is the most prevalent form of dementia characterized by the extracellular accumulation of amyloid β (Aβ) peptides, which are produced by proteolytic cleavages of amyloid precursor protein (APP). Gangliosides are involved in AD pathophysiology including Aβ deposition and APP processing, yet the detailed mechanisms are not fully understood. Here we examined how changes in the carbohydrate moiety of gangliosides alter APP processing in human melanoma cells, neuroectoderm-derived cells. We showed that forced expression of GD2, GM2 or GM1 (by introducing B4GALNT1 cDNA into cells not expressing this glycosyltransferase) results in increases of α- and β-site cleavages of APP with a prominent increase in β-cleavage. We also showed that β-site APP cleaving enzyme 1 (BACE1) protein is highly protected from the degradation in cells expressing these gangliosides, thereby increasing the expression of this protein. Unexpectedly, adding gangliosides exogenously altered neither BACE1 levels nor β-site cleavage. The stabilisation of BACE1 protein led to the increase of this protein in lipid rafts, where BACE1 processes APP. Based on the current results, we propose a hitherto undisclosed link between ganglioside expression and AD; the expression of B4GALNT1 positively regulates the β-site cleavage by mainly inhibiting the lysosomal degradation of BACE1 protein. PMID:27687691

  11. Phase Transitions of Spindle-Associated Protein Regulate Spindle Apparatus Assembly

    PubMed Central

    Jiang, Hao; Wang, Shusheng; Huang, Yuejia; He, Xiaonan; Cui, Honggang; Zhu, Xueliang; Zheng, Yixian

    2015-01-01

    Spindle assembly required during mitosis depends on microtubule polymerization. We demonstrate that the evolutionarily conserved low-complexity protein, BuGZ, undergoes phase transition or coacervation to promote assembly of both spindles and their associated components. BuGZ forms temperature-dependent liquid droplets alone or on microtubules in physiological buffers. Coacervation in vitro or in spindle and spindle matrix depends on hydrophobic residues in BuGZ. BuGZ coacervation and its binding to microtubules and tubulin are required to promote assembly of spindle and spindle matrix in Xenopus egg extract and in mammalian cells. Since several previously identified spindle-associated components also contain low complexity regions, we propose that coacervating proteins may be a hallmark of proteins that comprise a spindle matrix that functions to promote assembly of spindles by concentrating its building blocks. PMID:26388440

  12. Mobile app-based quantitative scanometric analysis.

    PubMed

    Wong, Jessica X H; Liu, Frank S F; Yu, Hua-Zhong

    2014-12-16

    The feasibility of using smartphones and other mobile devices as the detection platform for quantitative scanometric assays is demonstrated. The different scanning modes (color, grayscale, black/white) and grayscale converting protocols (average, weighted average/luminosity, and software specific) have been compared in determining the optical darkness ratio (ODR) values, a conventional quantitation measure for scanometric assays. A mobile app was developed to image and analyze scanometric assays, as demonstrated by paper-printed tests and a biotin-streptavidin assay on a plastic substrate. Primarily for ODR analysis, the app has been shown to perform as well as a traditional desktop scanner, augmenting that smartphones (and other mobile devices) promise to be a practical platform for accurate, quantitative chemical analysis and medical diagnostics.

  13. APP transgenic modeling of Alzheimer's disease: mechanisms of neurodegeneration and aberrant neurogenesis.

    PubMed

    Crews, Leslie; Rockenstein, Edward; Masliah, Eliezer

    2010-03-01

    Neurodegenerative disorders of the aging population affect over 5 million people in the US and Europe alone. The common feature is the progressive accumulation of misfolded proteins with the formation of toxic oligomers. Alzheimer's disease (AD) is characterized by cognitive impairment, progressive degeneration of neuronal populations in the neocortex and limbic system, and formation of amyloid plaques and neurofibrillary tangles. Amyloid-beta (Abeta) is the product of proteolysis of amyloid precursor protein (APP) by beta and gamma-secretase enzymes. The neurodegenerative process in AD initiates with axonal and synaptic damage and is associated with progressive accumulation of toxic Abeta oligomers in the intracellular and extracellular space. In addition, neurodegeneration in AD is associated with alterations in neurogenesis. Abeta accumulation is the consequence of an altered balance between protein synthesis, aggregation rate, and clearance. Identification of genetic mutations in APP associated with familial forms of AD and gene polymorphisms associated with the more common sporadic variants of AD has led to the development of transgenic (tg) and knock out rodents as well as viral vector driven models of AD. While APP tg murine models with mutations in the N- and C-terminal flanking regions of Abeta are characterized by increased Abeta production with plaque formation, mutations in the mid-segment of Abeta result in increased formation of oligomers, and mutations toward the C-terminus (E22Q) segment results in amyloid angiopathy. Similar to AD, in APP tg models bearing familial mutations, formation of Abeta oligomers results in defective plasticity in the perforant pathway, selective neuronal degeneration, and alterations in neurogenesis. Promising results have been obtained utilizing APP tg models of AD to develop therapies including the use of beta- and gamma-secretase inhibitors, immunization, and stimulating neurogenesis.

  14. Probing interactions and phase separations of proteins, colloids, and polymers with light scattering

    NASA Astrophysics Data System (ADS)

    Parmar, Avanish Singh

    The broad objective of my research is to investigate the physical characteristics and interactions of macromolecules and nanoparticles, and the corresponding effects on their phase separation behavior using static and dynamic light scattering (SLS & DLS). Light scattering provides a non-invasive technique for monitoring the in-situ behavior of solutes in solution, including solute interactions, sizes, shapes, aggregation kinetics and even rheological properties of condensed phases. Initially, we investigated lysozyme solutions for the presence of preformed aggregates and clusters that can distort the kinetics of protein crystal nucleation studies in this important model system for protein crystallization. We found that both undersaturated and supersaturated lysozyme solutions contained population of large, pre-existing protein aggregate. Separating these clusters and analyzing their composition with gel chromatography indicated that these clusters represented pre-formed lysozyme aggregates, and not extrinsic protein contamination. We investigated the effect of chaotropic versus kosmotropic ions (water structure breakers vs. structure makers) on the hydration layer and hydrodynamic interactions of hen egg white lysozyme. Surprisingly, neither chaotropic nor kosmotropic ions affected the protein hydration layer. Salt-effects on direct and hydrodynamic protein interactions were determined as function of the solutions ionic strength and temperature. Using both static and dynamic light scattering, we investigated the nucleation of gold nanoparticles forming from supersaturated gold sols. We observed that two well separated populations of nuclei formed essentially simultaneously, with sizes of 3nm vs. several tens of nanometer, respectively. We explore the use of lysozyme as tracer particle for diffusion-base measurements of electrolyte solutions. We showed that the unusual stability of lysozyme and its enhanced colloidal stability enable viscosity measurement of salts

  15. Audio App Brings a Better Nights Sleep

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Neuroscientist Seth Horowitz was part of a NASA-funded team at State University of New York Stony Brook demonstrating that low-amplitude vestibular stimulation could induce sleep. After recognizing the same stimulation could be applied through sound, Horowitz founded Sleep Genius, located in Park City, Utah, and released a mobile app of the same name that helps people to get a more restful sleep.

  16. Interferon-gamma and tumor necrosis factor-alpha regulate amyloid-beta plaque deposition and beta-secretase expression in Swedish mutant APP transgenic mice.

    PubMed

    Yamamoto, Masaru; Kiyota, Tomomi; Horiba, Masahide; Buescher, James L; Walsh, Shannon M; Gendelman, Howard E; Ikezu, Tsuneya

    2007-02-01

    Reactive astrocytes and microglia in Alzheimer's disease surround amyloid plaques and secrete proinflammatory cytokines that affect neuronal function. Relationship between cytokine signaling and amyloid-beta peptide (Abeta) accumulation is poorly understood. Thus, we generated a novel Swedish beta-amyloid precursor protein mutant (APP) transgenic mouse in which the interferon (IFN)-gamma receptor type I was knocked out (APP/GRKO). IFN-gamma signaling loss in the APP/GRKO mice reduced gliosis and amyloid plaques at 14 months of age. Aggregated Abeta induced IFN-gamma production from co-culture of astrocytes and microglia, and IFN-gamma elicited tumor necrosis factor (TNF)-alpha secretion in wild type (WT) but not GRKO microglia co-cultured with astrocytes. Both IFN-gamma and TNF-alpha enhanced Abeta production from APP-expressing astrocytes and cortical neurons. TNF-alpha directly stimulated beta-site APP-cleaving enzyme (BACE1) expression and enhanced beta-processing of APP in astrocytes. The numbers of reactive astrocytes expressing BACE1 were increased in APP compared with APP/GRKO mice in both cortex and hippocampus. IFN-gamma and TNF-alpha activation of WT microglia suppressed Abeta degradation, whereas GRKO microglia had no changes. These results support the idea that glial IFN-gamma and TNF-alpha enhance Abeta deposition through BACE1 expression and suppression of Abeta clearance. Taken together, these observations suggest that proinflammatory cytokines are directly linked to Alzheimer's disease pathogenesis.

  17. An interactive app for color deficient viewers

    NASA Astrophysics Data System (ADS)

    Lau, Cheryl; Perdu, Nicolas; Rodríguez-Pardo, Carlos E.; Süsstrunk, Sabine; Sharma, Gaurav

    2015-01-01

    Color deficient individuals have trouble seeing color contrasts that could be very apparent to individuals with normal color vision. For example, for some color deficient individuals, red and green apples do not have the striking contrast they have for those with normal color vision, or the abundance of red cherries in a tree is not immediately clear due to a lack of perceived contrast. We present a smartphone app that enables color deficient users to visualize such problematic color contrasts in order to help them with daily tasks. The user interacts with the app through the touchscreen. As the user traces a path around the touchscreen, the colors in the image change continuously via a transform that enhances contrasts that are weak or imperceptible for the user under native viewing conditions. Specifically, we propose a transform that shears the data along lines parallel to the dimension corresponding to the affected cone sensitivity of the user. The amount and direction of shear are controlled by the user's finger movement over the touchscreen allowing them to visualize these contrasts. Using the GPU, this simple transformation, consisting of a linear shear and translation, is performed efficiently on each pixel and in real-time with the changing position of the user's finger. The user can use the app to aid daily tasks such as distinguishing between red and green apples or picking out ripe bananas.

  18. 5-HT4 Receptors Constitutively Promote the Non-Amyloidogenic Pathway of APP Cleavage and Interact with ADAM10

    PubMed Central

    2012-01-01

    In addition to the amyloidogenic pathway, amyloid precursor protein (APP) can be cleaved by α-secretases, producing soluble and neuroprotective APP alpha (sAPPα) (nonamyloidogenic pathway) and thus preventing the generation of pathogenic amyloid-β. However, the mechanisms regulating APP cleavage by α-secretases remain poorly understood. Here, we showed that expression of serotonin type 4 receptors (5-HT4Rs) constitutively (without agonist stimulation) induced APP cleavage by the α-secretase ADAM10 and the release of neuroprotective sAPPα in HEK-293 cells and cortical neurons. This effect was independent of cAMP production. Interestingly, we demonstrated that 5-HT4 receptors physically interacted with the mature form of ADAM10. Stimulation of 5-HT4 receptors by an agonist further increased sAPPα secretion, and this effect was mediated by cAMP/Epac signaling. These findings describe a new mechanism whereby a GPCR constitutively stimulates the cleavage of APP by α-secretase and promotes the nonamyloidogenic pathway of APP processing. PMID:23336052

  19. Interrater Reliability of mHealth App Rating Measures: Analysis of Top Depression and Smoking Cessation Apps

    PubMed Central

    Chan, Steven; Raynor, Geoffrey Stephen; Shwarts, Erik; Shanahan, Meghan; Landman, Adam B

    2016-01-01

    Background There are over 165,000 mHealth apps currently available to patients, but few have undergone an external quality review. Furthermore, no standardized review method exists, and little has been done to examine the consistency of the evaluation systems themselves. Objective We sought to determine which measures for evaluating the quality of mHealth apps have the greatest interrater reliability. Methods We identified 22 measures for evaluating the quality of apps from the literature. A panel of 6 reviewers reviewed the top 10 depression apps and 10 smoking cessation apps from the Apple iTunes App Store on these measures. Krippendorff’s alpha was calculated for each of the measures and reported by app category and in aggregate. Results The measure for interactiveness and feedback was found to have the greatest overall interrater reliability (alpha=.69). Presence of password protection (alpha=.65), whether the app was uploaded by a health care agency (alpha=.63), the number of consumer ratings (alpha=.59), and several other measures had moderate interrater reliability (alphas>.5). There was the least agreement over whether apps had errors or performance issues (alpha=.15), stated advertising policies (alpha=.16), and were easy to use (alpha=.18). There were substantial differences in the interrater reliabilities of a number of measures when they were applied to depression versus smoking apps. Conclusions We found wide variation in the interrater reliability of measures used to evaluate apps, and some measures are more robust across categories of apps than others. The measures with the highest degree of interrater reliability tended to be those that involved the least rater discretion. Clinical quality measures such as effectiveness, ease of use, and performance had relatively poor interrater reliability. Subsequent research is needed to determine consistent means for evaluating the performance of apps. Patients and clinicians should consider conducting their

  20. Investigating gas phase dissociation pathways of crosslinked peptides : application to protein complex determination.

    SciTech Connect

    Young, Malin M.; Gaucher, Sara P.; Hadi, Masood Z.

    2005-02-01

    Chemical crosslinking is an important tool for probing protein structure and protein-protein interactions. The approach usually involves crosslinking of specific amino acids within a folded protein or protein complex, enzymatic digestion of the crosslinked protein(s), and identification of the resulting crosslinked peptides by liquid chromatography/mass spectrometry (LC/MS). In this manner, distance constraints are obtained for residues that must be in close proximity to one another in the native structure or complex. As the complexity of the system under study increases, for example, a large multi-protein complex, simply measuring the mass of a crosslinked species will not always be sufficient to determine the identity of the crosslinked peptides. In such a case, tandem mass spectrometry (MS/MS) could provide the required information if the data can be properly interpreted. In MS/MS, a species of interest is isolated in the gas phase and allowed to undergo collision induced dissociation (CID). Because the gas-phase dissociation pathways of peptides have been well studied, methods are established for determining peptide sequence by MS/MS. However, although crosslinked peptides dissociate through some of the same pathways as isolated peptides, the additional dissociation pathways available to the former have not been studied in detail. Software such as MS2Assign has been written to assist in the interpretation of MS/MS from crosslinked peptide species, but it would be greatly enhanced by a more thorough understanding of how these species dissociate. We are thus systematically investigating the dissociation pathways open to crosslinked peptide species. A series of polyalanine and polyglycine model peptides have been synthesized containing one or two lysine residues to generate defined inter- and intra-molecular crosslinked species, respectively. Each peptide contains 11 total residues, and one arginine residue is present at the carboxy terminus to mimic species

  1. Mitochondrial trafficking of APP and alpha synuclein: Relevance to mitochondrial dysfunction in Alzheimer's and Parkinson's diseases.

    PubMed

    Devi, Latha; Anandatheerthavarada, Hindupur K

    2010-01-01

    Mitochondrial dysfunction is an important intracellular lesion associated with a wide variety of diseases including neurodegenerative disorders. In addition to aging, oxidative stress and mitochondrial DNA mutations, recent studies have implicated a role for the mitochondrial accumulation of proteins such as plasma membrane associated amyloid precursor protein (APP) and cytosolic alpha synuclein in the pathogenesis of mitochondrial dysfunction in Alzheimer's disease (AD) and Parkinson's disease (PD), respectively. Both of these proteins contain cryptic mitochondrial targeting signals, which drive their transport across mitochondria. In general, mitochondrial entry of nuclear coded proteins is assisted by import receptors situated in both outer and inner mitochondrial membranes. A growing number of evidence suggests that APP and alpha synclein interact with import receptors to gain entry into mitochondrial compartment. Additionally, carboxy terminal cleaved product of APP, approximately 4 kDa Abeta, is also transported into mitochondria with the help of mitochondrial outer membrane import receptors. This review focuses on the mitochondrial targeting and accumulation of these two structurally different proteins and the mode of mechanism by which they affect the physiological functions of mitochondria.

  2. Electron transfer quenching in light adapted and mutant forms of the AppA BLUF domain.

    PubMed

    Laptenok, Sergey P; Lukacs, Andras; Brust, Richard; Haigney, Allison; Gil, Agnieszka; Towrie, Michael; Greetham, Gregory M; Tonge, Peter J; Meech, Stephen R

    2015-01-01

    The Blue Light Using Flavin (BLUF) domain proteins are an important family of photoreceptors controlling a range of responses in a wide variety of organisms. The details of the primary photochemical mechanism, by which light absorption in the isoalloxazine ring of the flavin is converted into a structure change to form the signalling state of the protein, is unresolved. In this work we apply ultrafast time resolved infra-red (TRIR) spectroscopy to investigate the primary photophysics of the BLUF domain of the protein AppA (AppABLUF) a light activated antirepressor. Here a number of mutations at Y21 and W104 in AppABLUF are investigated. The Y21 mutants are known to be photoinactive, while W104 mutants show the characteristic spectral red-shift associated with BLUF domain activity. Using TRIR we observed separately the decay of the excited state and the recovery of the ground state. In both cases the kinetics are found to be non-single exponential for all the proteins studied, suggesting a range of ground state structures. In the Y21 mutants an intermediate state was also observed, assigned to formation of the radical of the isoalloxazine (flavin) ring. The electron donor is the W104 residue. In contrast, no radical intermediates were detected in the studies of the photoactive dark adapted proteins, dAppABLUF and the dW104 mutants, suggesting a structure change in the Y21 mutants which favours W104 to isoalloxazine electron transfer. In contrast, in the light adapted form of the proteins (lAppABLUF, lW104) a radical intermediate was detected and the kinetics were greatly accelerated. In this case the electron donor was Y21 and major structural changes are associated with the enhanced quenching. In AppABLUF and the seven mutants studied radical intermediates are readily observed by TRIR spectroscopy, but there is no correlation with photoactivity. This suggests that if a charge separated state has a role in the BLUF photocycle it is only as a very short lived

  3. Structure and Interaction in the pH-Dependent Phase Behavior of Nanoparticle-Protein Systems.

    PubMed

    Yadav, Indresh; Kumar, Sugam; Aswal, Vinod K; Kohlbrecher, Joachim

    2017-02-07

    The pH-dependent structure and interaction of anionic silica nanoparticles (diameter 18 nm) with two globular model proteins, lysozyme and bovine serum albumin (BSA), have been studied. Cationic lysozyme adsorbs strongly on the nanoparticles, and the adsorption follows exponential growth as a function of lysozyme concentration, where the saturation value increases as pH approaches the isoelectric point (IEP) of lysozyme. By contrast, irrespective of pH, anionic BSA does not show any adsorption. Despite having a different nature of interactions, both proteins render a similar phase behavior where nanoparticle-protein systems transform from being one-phase (clear) to two-phase (turbid) above a critical protein concentration (CPC). The measurements have been carried out for a fixed concentration of silica nanoparticles (1 wt %) with varying protein concentrations (0-5 wt %). The CPC is found to be much higher for BSA than for lysozyme and increases for lysozyme but decreases for BSA as pH approaches their respective IEPs. The structure and interaction in these systems have been examined using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The effective hydrodynamic size of the nanoparticles measured using DLS increases with protein concentration and is related to the aggregation of the nanoparticles above the CPC. The propensity of the nanoparticles to aggregate is suppressed for lysozyme and enhanced for BSA as pH approached their respective IEPs. This behavior is understood from SANS data through the interaction potential determined by the interplay of electrostatic repulsion with a short-range attraction for lysozyme and long-range attraction for BSA. The nanoparticle aggregation is caused by charge neutralization by the oppositely charged lysozyme and through depletion for similarly charged BSA. Lysozyme-mediated attractive interaction decreases as pH approaches the IEP because of a decrease in the charge on the protein. In the case of

  4. Quantitative immunoelectrophoretic analysis of the plasma proteins in the sol phase of sputum from patients with chronic bronchitis

    PubMed Central

    Ryley, H. C.; Brogan, T. D.

    1973-01-01

    An analysis of the plasma proteins in the sol phase of sputum was carried out using quantitative cross immunoelectrophoresis. The average concentrations of nine plasma proteins were estimated in the sol phase of sputum specimens from 30 patients with chronic bronchitis and the values were compared with the concentrations of these proteins in saliva and serum specimens from the same group of patients. The results showed that alpha1 antichymotrypsin and IgA concentrations were higher in the sol phase of sputum than would be expected if their presence were due entirely to passive transudation. Images PMID:4128930

  5. Assembly, Properties and Function of Synthetic Phase-Separated RNA/Protein Organelles

    NASA Astrophysics Data System (ADS)

    Taylor, Nicole; Elbaum, Shana; Stone, Howard; Brangwynne, Clifford

    2015-03-01

    Non-membrane bound RNA/protein (RNP) bodies play a key role in cellular RNA processing steps. Many RNA helicases, required for RNA processing, are key components of RNPs. Consistent with this, a purified RNA helicase, Laf-1, exhibits a salt and protein concentration dependent phase separation in vitro, resulting in liquid-like droplets. We use such synthetic RNPs to study the biophysics of RNP assembly, and to elucidate the link between their physical properties and function. To accomplish this, we are developing custom microfluidic devices to measure biophysical properties, nucleation and growth kinetics, and RNA processing function of droplets. We measure droplet viscosity by applying a shear stress to protein droplets that adhere to the channel wall; measurements are consistent with those taken using a particle microrheology approach. We also monitor and control protein droplet nucleation using oil/water emulsions. Our results provide a new platform for addressing how the cell regulates organelle assembly and properties through protein, RNA, and ATP concentration. We anticipate that these findings will offer insight into the contribution of RNPs in key RNA processing functions in the cell.

  6. The SIT4 protein phosphatase functions in late G1 for progression into S phase.

    PubMed Central

    Sutton, A; Immanuel, D; Arndt, K T

    1991-01-01

    Saccharomyces cerevisiae strains containing temperature-sensitive mutations in the SIT4 protein phosphatase arrest in late G1 at the nonpermissive temperature. Order-of-function analysis shows that SIT4 is required in late G1 for progression into S phase. While the levels of SIT4 do not change in the cell cycle, SIT4 associates with two high-molecular-weight phosphoproteins in a cell-cycle-dependent fashion. In addition, we have identified a polymorphic gene, SSD1, that in some versions can suppress the lethality due to a deletion of SIT4 and can also partially suppress the phenotypic defects due to a null mutation in BCY1. The SSD1 protein is implicated in G1 control and has a region of similarity to the dis3 protein of Schizosaccharomyces pombe. We have also identified a gene, PPH2alpha, that in high copy number can partially suppress the growth defect of sit4 strains. The PPH2 alpha gene encodes a predicted protein that is 80% identical to the catalytic domain of mammalian type 2A protein phosphatases but also has an acidic amino-terminal extension not present in other phosphatases. Images PMID:1848673

  7. Phase Sensitive X-Ray Diffraction Imaging Study of Protein Crystals

    NASA Technical Reports Server (NTRS)

    Hu, Z. W.

    2003-01-01

    The study of defects and growth of protein crystals is of importance in providing a fundamental understanding of this important category of systems and the rationale for crystallization of better ordered crystals for structural determination and drug design. Yet, as a result of the extremely weak scattering power of x-rays in protein and other biological macromolecular crystals, the extinction lengths for those crystals are extremely large and, roughly speaking, of the order of millimeters on average compared to the scale of micrometers for most small molecular crystals. This has significant implication for x-ray diffraction and imaging study of protein crystals, and presents an interesting challenge to currently available x-ray analytical techniques. We proposed that coherence-based phase sensitive x-ray diffraction imaging could provide a way to augment defect contrast in x-ray diffraction images of weakly diffracting biological macromolecular crystals. I shall examine the principles and ideas behind this approach and compare it to other available x-ray topography and diffraction methods. I shall then present some recent experimental results in two model protein systems-cubic apofemtin and tetragonal lysozyme crystals to demonstrate the capability of the coherence-based imaging method in mapping point defects, dislocations, and the degree of perfection of biological macromolecular crystals with extreme sensitivity. While further work is under way, it is intended to show that the observed new features have yielded important information on protein crystal perfection and nucleation and growth mechanism otherwise unobtainable.

  8. Development of optimized mobile phases for protein separation by high performance thin layer chromatography.

    PubMed

    Biller, Julia; Morschheuser, Lena; Riedner, Maria; Rohn, Sascha

    2015-10-09

    In recent years, protein chemistry tends inexorably toward the analysis of more complex proteins, proteoforms, and posttranslational protein modifications. Although mass spectrometry developed quite fast correspondingly, sample preparation and separation of these analytes is still a major issue and quite challenging. For many years, electrophoresis seemed to be the method of choice; nonetheless its variance is limited to parameters such as size and charge. When taking a look at traditional (thin-layer) chromatography, further parameters such as polarity and different mobile and stationary phases can be utilized. Further, possibilities of detection are manifold compared to electrophoresis. Similarly, two-dimensional separation can be also performed with thin-layer chromatography (TLC). As the revival of TLC developed enormously in the last decade, it seems to be also an alternative to use high performance thin-layer chromatography (HPTLC) for the separation of proteins. The aim of this study was to establish an HPTLC separation system that allows a separation of protein mixtures over a broad polarity range, or if necessary allowing to modify the separation with only few steps to improve the separation for a specific scope. Several layers and solvent systems have been evaluated to reach a fully utilized and optimized separation system.

  9. Description and control of dissociation channels in gas-phase protein complexes

    NASA Astrophysics Data System (ADS)

    Thachuk, Mark; Fegan, Sarah K.; Raheem, Nigare

    2016-08-01

    Using molecular dynamics simulations of a coarse-grained model of the charged apo-hemoglobin protein complex, this work expands upon our initial report [S. K. Fegan and M. Thachuk, J. Am. Soc. Mass Spectrom. 25, 722-728 (2014)] about control of dissociation channels in the gas phase using specially designed charge tags. Employing a charge hopping algorithm and a range of temperatures, a variety of dissociation channels are found for activated gas-phase protein complexes. At low temperatures, a single monomer unfolds and becomes charge enriched. At higher temperatures, two additional channels open: (i) two monomers unfold and charge enrich and (ii) two monomers compete for unfolding with one eventually dominating and the other reattaching to the complex. At even higher temperatures, other more complex dissociation channels open with three or more monomers competing for unfolding. A model charge tag with five sites is specially designed to either attract or exclude charges. By attaching this tag to the N-terminus of specific monomers, the unfolding of those monomers can be decidedly enhanced or suppressed. In other words, using charge tags to direct the motion of charges in a protein complex provides a mechanism for controlling dissociation. This technique could be used in mass spectrometry experiments to direct forces at specific attachment points in a protein complex, and hence increase the diversity of product channels available for quantitative analysis. In turn, this could provide insight into the function of the protein complex in its native biological environment. From a dynamics perspective, this system provides an interesting example of cooperative behaviour involving motions with differing time scales.

  10. Strategy for allosteric analysis based on protein-patterned stationary phase in microfluidic chip.

    PubMed

    Bi, Hongyan; Weng, Xuexiang; Qu, Haiyun; Kong, Jilie; Yang, Pengyuan; Liu, Baohong

    2005-01-01

    An effective method is presented for the on-chip analysis of chiral interactions with a successful depression of nonspecific adsorption. The alumina gel-derived protein network on poly(methyl methacrylate) (PMMA) microchannel was explored to form a protein-stationary phase and then used to carry out electrophoresis for fast enantioseparation coupled with electrochemical detection. On the basis of the chemical modification of a synthesized copolymer containing silane-functionalized scaffold, alumina sol-gel could react readily with the silane groups and form steady microstructure on the chip surface achieving the encapsulation of functional biomolecules. Compared with the native PMMA microchannels, the modified surfaces exhibited much better wettability, more stable and enhanced electroosmotic mobility, and less nonspecific adsorption. The water contact angle and EOF of alumina-gel-derived PMMA substrate were 22 degrees and 4.3 x 10(-4) cm(2) V(-1) s(-1), compared to those of 73 degrees and 1.9 x 10(-4) cm(2) V(-1) s(-1) from the untreated one, respectively. Bovine serum albumin, acting as a target protein, could be stably and homogeneously immobilized in the modified PMMA microchannel to fabricate a protein-stationary phase. Under a mild condition, D- and L-tryptophan were efficiently separated with a resolution of 1.57. The as-prepared microchip can perform chiral separations within short time, indicating that the general protocol has the potential to provide a platform for high throughput screening of enantiomer candidates such as those biochemical drugs with protein targets and the research of receptor interactions.

  11. Clinical utility of reverse phase protein array for molecular classification of breast cancer.

    PubMed

    Negm, Ola H; Muftah, Abir A; Aleskandarany, Mohammed A; Hamed, Mohamed R; Ahmad, Dena A J; Nolan, Christopher C; Diez-Rodriguez, Maria; Tighe, Patrick J; Ellis, Ian O; Rakha, Emad A; Green, Andrew R

    2016-01-01

    Reverse Phase Protein Array (RPPA) represents a sensitive and high-throughput technique allowing simultaneous quantitation of protein expression levels in biological samples. This study aimed to confirm the ability of RPPA to classify archival formalin-fixed paraffin-embedded (FFPE) breast cancer tissues into molecular classes used in the Nottingham prognostic index plus (NPI+) determined by immunohistochemistry (IHC). Proteins were extracted from FFPE breast cancer tissues using three extraction protocols: the Q-proteome FFPE Tissue Kit (Qiagen, Hilden, Germany) and two in-house methods using Laemmli buffer with either incubation for 20 min or 2 h at 105 °C. Two preparation methods, full-face sections and macrodissection, were used to assess the yield and quality of protein extracts. Ten biomarkers used for the NPI+ (ER, PgR, HER2, Cytokeratins 5/6 and 7/8, EGFR, HER3, HER4, p53 and Mucin 1) were quantified using RPPA and compared to results determined by IHC. The Q-proteome FFPE Tissue Kit produced significantly higher protein concentration and signal intensities. The intra- and inter-array reproducibility assessment indicated that RPPA using FFPE lysates was a highly reproducible and robust technique. Expression of the biomarkers individually and in combination using RPPA was highly consistent with IHC results. Macrodissection of the invasive tumour component gave more reliable results with the majority of biomarkers determined by IHC, (80 % concordance) compared with full-face sections (60 % concordance). Our results provide evidence for the technical feasibility of RPPA for high-throughput protein expression profiling of FFPE breast cancer tissues. The sensitivity of the technique is related to the quality of extracted protein and purity of tumour tissue. RPPA could provide a quantitative technique alternative to IHC for the biomarkers used in the NPI+.

  12. Effect of Excipients on Liquid-Liquid Phase Separation and Aggregation in Dual Variable Domain Immunoglobulin Protein Solutions.

    PubMed

    Raut, Ashlesha S; Kalonia, Devendra S

    2016-03-07

    Liquid-liquid phase separation (LLPS) and aggregation can reduce the physical stability of therapeutic protein formulations. On undergoing LLPS, the protein-rich phase can promote aggregation during storage due to high concentration of the protein. Effect of different excipients on aggregation in protein solution is well documented; however data on the effect of excipients on LLPS is scarce in the literature. In this study, the effect of four excipients (PEG 400, Tween 80, sucrose, and hydroxypropyl beta-cyclodextrin (HPβCD)) on liquid-liquid phase separation and aggregation in a dual variable domain immunoglobulin protein solution was investigated. Sucrose suppressed both LLPS and aggregation, Tween 80 had no effect on either, and PEG 400 increased LLPS and aggregation. Attractive protein-protein interactions and liquid-liquid phase separation decreased with increasing concentration of HPβCD, indicating its specific binding to the protein. However, HPβCD had no effect on the formation of soluble aggregates and fragments in this study. LLPS and aggregation are highly temperature dependent; at low temperature protein exhibits LLPS, at high temperature protein exhibits aggregation, and at an intermediate temperature both phenomena occur simultaneously depending on the solution conditions.

  13. Visualization of membrane protein crystals in lipid cubic phase using X-ray imaging

    SciTech Connect

    Warren, Anna J.; Armour, Wes; Axford, Danny; Basham, Mark; Connolley, Thomas; Hall, David R.; Horrell, Sam; McAuley, Katherine E.; Mykhaylyk, Vitaliy; Wagner, Armin; Evans, Gwyndaf

    2013-07-01

    A comparison of X-ray diffraction and radiographic techniques for the location and characterization of protein crystals is demonstrated on membrane protein crystals mounted within lipid cubic phase material. The focus in macromolecular crystallography is moving towards even more challenging target proteins that often crystallize on much smaller scales and are frequently mounted in opaque or highly refractive materials. It is therefore essential that X-ray beamline technology develops in parallel to accommodate such difficult samples. In this paper, the use of X-ray microradiography and microtomography is reported as a tool for crystal visualization, location and characterization on the macromolecular crystallography beamlines at the Diamond Light Source. The technique is particularly useful for microcrystals and for crystals mounted in opaque materials such as lipid cubic phase. X-ray diffraction raster scanning can be used in combination with radiography to allow informed decision-making at the beamline prior to diffraction data collection. It is demonstrated that the X-ray dose required for a full tomography measurement is similar to that for a diffraction grid-scan, but for sample location and shape estimation alone just a few radiographic projections may be required.

  14. Extraction of proteins with ionic liquid aqueous two-phase system based on guanidine ionic liquid.

    PubMed

    Zeng, Qun; Wang, Yuzhi; Li, Na; Huang, Xiu; Ding, Xueqin; Lin, Xiao; Huang, Songyun; Liu, Xiaojie

    2013-11-15

    Eight kinds of green ionic liquids were synthesized, and an ionic liquid aqueous two-phase system (ILATPS) based on 1,1,3,3-tetramethylguandine acrylate (TMGA) guanidine ionic liquid was first time studied for the extraction of proteins. Single factor experiments proved that the extraction efficiency of bovine serum albumin (BSA) was influenced by the mass of IL, K2HPO4 and BSA, also related to the separation time and temperature. The optimum conditions were determined through orthogonal experiment by the five factors described above. The results showed that under the optimum conditions, the extraction efficiency could reach up to 99.6243%. The relative standard deviations (RSD) of extraction efficiencies in precision experiment, repeatability experiment and stability experiment were 0.8156% (n=5), 1.6173% (n=5) and 1.6292% (n=5), respectively. UV-vis and FT-IR spectra confirmed that there were no chemical interactions between BSA and ionic liquid in the extraction process, and the conformation of the protein was not changed after extraction. The conductivity, DLS and TEM were combined to investigate the microstructure of the top phase and the possible mechanism for the extraction. The results showed that hydrophobic interaction, hydrogen bonding interaction and the salt out effect played important roles in the transferring process, and the aggregation and embrace phenomenon was the main driving force for the separation. All these results proved that guanidine ionic liquid-based ATPSs have the potential to offer new possibility in the extraction of proteins.

  15. Dynamic sorting of lipids and proteins in membrane tubes with a moving phase boundary

    PubMed Central

    Heinrich, Michael; Tian, Aiwei; Esposito, Cinzia; Baumgart, Tobias

    2010-01-01

    Cellular organelle membranes maintain their integrity, global shape, and composition despite vigorous exchange among compartments of lipids and proteins during trafficking and signaling. Organelle homeostasis involves dynamic molecular sorting mechanisms that are far from being understood. In contrast, equilibrium thermodynamics of membrane mixing and sorting, particularly the phase behavior of binary and ternary model membrane mixtures and its coupling to membrane mechanics, is relatively well characterized. Elucidating the continuous turnover of live cell membranes, however, calls for experimental and theoretical membrane models enabling manipulation and investigation of directional mass transport. Here we introduce the phenomenon of curvature-induced domain nucleation and growth in membrane mixtures with fluid phase coexistence. Membrane domains were consistently observed to nucleate precisely at the junction between a strongly curved cylindrical (tube) membrane and a pipette-aspirated giant unilamellar vesicle. This experimental geometry mimics intracellular sorting compartments, because they often show tubular-vesicular membrane regions. Nucleated domains at tube necks were observed to present diffusion barriers to the transport of lipids and proteins. We find that curvature-nucleated domains grow with characteristic parabolic time dependence that is strongly curvature-dependent. We derive an analytical model that reflects the observed growth dynamics. Numerically calculated membrane shapes furthermore allow us to elucidate mechanical details underlying curvature-dependent directed lipid transport. Our observations suggest a novel dynamic membrane sorting principle that may contribute to intracellular protein and lipid sorting and trafficking. PMID:20368457

  16. Reagent Cluster Anions for Multiple Gas-phase Covalent Modifications of Peptide and Protein Cations

    PubMed Central

    Prentice, Boone M.; Stutzman, John R.; McLuckey, Scott A.

    2013-01-01

    Multiple gas phase ion/ion covalent modifications of peptide and protein ions are demonstrated here using cluster-type reagent anions of N-hydroxysulfosuccinimide acetate (sulfo-NHS acetate) and 2-formyl-benzenesulfonic acid (FBMSA). These reagents are used here to selectively modify unprotonated primary amine functionalities of peptides and proteins. Multiple reactive reagent molecules can be present in a single cluster ion, which allows for multiple covalent modifications to be achieved in a single ion/ion encounter and at the ‘cost’ of only a single analyte charge. Multiple derivatizations are demonstrated when the number of available reactive sites on the analyte cation exceeds the number of reagent molecules in the anionic cluster (e.g., data shown here for reactions between the polypeptide [K10+3H]3+ and the reagent cluster [5R5Na-Na]−). This type of gas phase ion chemistry is also applicable to whole protein ions. Here, ubiquitin was successfully modified using an FBMSA cluster anions which, upon collisional activation, produced fragment ions with various numbers of modifications. Data for the pentamer cluster are included here as illustrative of the results obtained for the clusters comprised of 2–6 reagent molecules. PMID:23702708

  17. Apps Seeking Theories: Results of a Study on the Use of Health Behavior Change Theories in Cancer Survivorship Mobile Apps

    PubMed Central

    Fair, Kayla; Hong, Y Alicia; Beaudoin, Christopher E; Pulczinski, Jairus; Ory, Marcia G

    2015-01-01

    Background Thousands of mobile health apps are now available for use on mobile phones for a variety of uses and conditions, including cancer survivorship. Many of these apps appear to deliver health behavior interventions but may fail to consider design considerations based in human computer interface and health behavior change theories. Objective This study is designed to assess the presence of and manner in which health behavior change and health communication theories are applied in mobile phone cancer survivorship apps. Methods The research team selected a set of criteria-based health apps for mobile phones and assessed each app using qualitative coding methods to assess the application of health behavior change and communication theories. Each app was assessed using a coding derived from the taxonomy of 26 health behavior change techniques by Abraham and Michie with a few important changes based on the characteristics of mHealth apps that are specific to information processing and human computer interaction such as control theory and feedback systems. Results A total of 68 mobile phone apps and games built on the iOS and Android platforms were coded, with 65 being unique. Using a Cohen’s kappa analysis statistic, the inter-rater reliability for the iOS apps was 86.1 (P<.001) and for the Android apps, 77.4 (P<.001). For the most part, the scores for inclusion of theory-based health behavior change characteristics in the iOS platform cancer survivorship apps were consistently higher than those of the Android platform apps. For personalization and tailoring, 67% of the iOS apps (24/36) had these elements as compared to 38% of the Android apps (12/32). In the area of prompting for intention formation, 67% of the iOS apps (34/36) indicated these elements as compared to 16% (5/32) of the Android apps. Conclusions Mobile apps are rapidly emerging as a way to deliver health behavior change interventions that can be tailored or personalized for individuals. As these

  18. Presymptomatic alterations in energy metabolism and oxidative stress in the APP23 mouse model of Alzheimer disease.

    PubMed

    Hartl, Daniela; Schuldt, Victoria; Forler, Stephanie; Zabel, Claus; Klose, Joachim; Rohe, Michael

    2012-06-01

    Glucose hypometabolism is the earliest symptom observed in the brains of Alzheimer disease (AD) patients. In a former study, we analyzed the cortical proteome of the APP23 mouse model of AD at presymptomatic age (1 month) using a 2-D electrophoresis-based approach. Interestingly, long before amyloidosis can be observed in APP23 mice, proteins associated with energy metabolism were predominantly altered in transgenic as compared to wild-type mice indicating presymptomatic changes in energy metabolism. In the study presented here, we analyzed whether the observed changes were associated with oxidative stress and confirmed our previous findings in primary cortical neurons, which exhibited altered ADP/ATP levels if transgenic APP was expressed. Reactive oxygen species produced during energy metabolism have important roles in cell signaling and homeostasis as they modify proteins. We observed an overall up-regulation of protein oxidation status as shown by increased protein carbonylation in the cortex of presymptomatic APP23 mice. Interestingly, many carbonylated proteins, such as Vilip1 and Syntaxin were associated to synaptic plasticity. This demonstrates an important link between energy metabolism and synaptic function, which is altered in AD. In summary, we demonstrate that changes in cortical energy metabolism and increased protein oxidation precede the amyloidogenic phenotype in a mouse model for AD. These changes might contribute to synaptic failure observed in later disease stages, as synaptic transmission is particularly dependent on energy metabolism.

  19. Just a Fad? Gamification in Health and Fitness Apps

    PubMed Central

    2014-01-01

    Background Gamification has been a predominant focus of the health app industry in recent years. However, to our knowledge, there has yet to be a review of gamification elements in relation to health behavior constructs, or insight into the true proliferation of gamification in health apps. Objective The objective of this study was to identify the extent to which gamification is used in health apps, and analyze gamification of health and fitness apps as a potential component of influence on a consumer’s health behavior. Methods An analysis of health and fitness apps related to physical activity and diet was conducted among apps in the Apple App Store in the winter of 2014. This analysis reviewed a sample of 132 apps for the 10 effective game elements, the 6 core components of health gamification, and 13 core health behavior constructs. A regression analysis was conducted in order to measure the correlation between health behavior constructs, gamification components, and effective game elements. Results This review of the most popular apps showed widespread use of gamification principles, but low adherence to any professional guidelines or industry standard. Regression analysis showed that game elements were associated with gamification (P<.001). Behavioral theory was associated with gamification (P<.05), but not game elements, and upon further analysis gamification was only associated with composite motivational behavior scores (P<.001), and not capacity or opportunity/trigger. Conclusions This research, to our knowledge, represents the first comprehensive review of gamification use in health and fitness apps, and the potential to impact health behavior. The results show that use of gamification in health and fitness apps has become immensely popular, as evidenced by the number of apps found in the Apple App Store containing at least some components of gamification. This shows a lack of integrating important elements of behavioral theory from the app industry

  20. BACE2, as a novel APP theta-secretase, is not responsible for the pathogenesis of Alzheimer's disease in Down syndrome.

    PubMed

    Sun, Xiulian; He, Guiqiong; Song, Weihong

    2006-07-01

    Amyloid beta protein (Abeta), the major component of neuritic plaques in Alzheimer's disease (AD), is derived from APP by sequential cleavages of beta- and gamma-secretases. Beta-site APP cleaving enzyme 1 (BACE1) is the major beta-secretase in vivo. Beta-site APP cleaving enzyme 2 (BACE2) is the homologue of BACE1. The majority of people with Down syndrome (DS), also called Trisomy 21 syndrome, will develop AD neuropathology after middle age. We and others have shown that APP C99, the major beta-secretase product, and Abeta are markedly increased in DS. Since BACE2 is located on chromosome 21, it is speculated that BACE2 may play a role in AD pathogenesis in DS. In this report we found that BACE2 cleaves APP at a novel theta site downstream of the alpha site, abolishing Abeta production. Overexpression of BACE2 by lentivirus markedly reduced Abeta production in primary neurons derived from Swedish mutant APP transgenic mice. Despite an extra copy of the BACE2 gene in DS and the increase of its transcription, BACE2 protein levels are unchanged. Our data clearly demonstrate that BACE2, as a novel theta-secretase to cleave APP within the Abeta domain, is not involved in the AD pathogenesis of DS patients; instead, therapeutic interventions that potentiate BACE2 may prevent AD pathogenesis.

  1. Meteor reporting made easy- The Fireballs in the Sky smartphone app

    NASA Astrophysics Data System (ADS)

    Sansom, E.; Ridgewell, J.; Bland, P.; Paxman, J.

    2016-01-01

    Using smartphone technology, the award-winning 'Fireballs in the Sky' app provides a new approach to public meteor reporting. Using the internal GPS and sensors of a smartphone, a user can record the start and end position of a meteor sighting with a background star field as reference. Animations are used to visualize the duration and characteristics of the meteor. The intuitive application can be used in situ, providing a more accurate eye witness account than after-the-fact reports (although reports may also be made through a website interface). Since its launch in 2013, the app has received over 2000 submissions, including 73 events which were reported by multiple users. The app database is linked to the Desert Fireball Network in Australia (DFN), meaning app reports can be confirmed by DFN observatories. Supporting features include an integrated meteor shower tool that provides updates on active showers, their visibility based on moon phase, as well as a tool to point the user toward the radiant. The locations of reports are also now shown on a live map on the Fireballs in the Sky webpage.

  2. PEG chain length impacts yield of solid-phase protein PEGylation and efficiency of PEGylated protein separation by ion-exchange chromatography: insights of mechanistic models.

    PubMed

    Yoshimoto, Noriko; Isakari, Yu; Itoh, Daisuke; Yamamoto, Shuichi

    2013-07-01

    The mechanisms behind protein PEGylation are complex and dictated by the structure of the protein reactant. Hence, it is difficult to design a reaction process which can produce the desired PEGylated form at high yield. Likewise, efficient purification processes following protein PEGylation must be constructed on an ad hoc basis for each product. The retention and binding mechanisms driving electrostatic interaction-based chromatography (ion-exchange chromatography) of PEGylated proteins (randomly PEGylated lysozyme and mono-PEGylated bovine serum albumin) were investigated, based on our previously developed model Chem. Eng. Technol. 2005, 28, 1387-1393. PEGylation of each protein resulted in a shift to a smaller elution volume compared to the unmodified molecule, but did not affect the number of binding sites appreciably. The shift of the retention volume of PEGylated proteins correlated with the calculated thickness of PEG layer around the protein molecule. Random PEGylation was carried out on a column (solid-phase PEGylation) and the PEGylated proteins were separated on the same column. Solid-phase PEGylation inhibited the production of multi-PEGylated forms and resulted in a relatively low yield of selective mono-PEGylated form. Pore diffusion may play an important role in solid-phase PEGylation. These results suggest the possibility of a reaction and purification process development based on the mechanistic model for PEGylated proteins on ion exchange chromatography.

  3. APP processing enzymes (secretases) as therapeutic targets: insights from the use of transgenics (Tgs) and transfected cells.

    PubMed

    Marks, Neville; Berg, Martin J

    2003-07-01

    Secretases degrade amyloid precursor protein (APP) releasing fragments (beta-peptides A beta, A beta x) that assemble to form hallmark extracellular deposits in Alzheimer's disease (AD) correlating with disease severity. As such, secretases supply targets for therapeutic intervention and form the focus of this overview. Progress in elucidating secretases and their modes of catalysis come from exploiting the use of transgenics or transfected cells. In addition to A beta x, secretases also release C-terminal fragments with putative signaling properties (amyloid intracellular domain, AICD) similar in concept to those available for conversion of the Notch-r to release the nuclear transactivator NICD. The review considers lingering questions on APP fragmentation by secretase action, ancillary proteins such as presenilins (PS1/2), nicastrin, XII, or proteases (caspases), and the influence of familial mutations (mAPP, mPS) in terms of fibrillogenesis.

  4. Alternative splicing of VEGFA, APP and NUMB genes in colorectal cancer

    PubMed Central

    Zhao, Yi-Jun; Han, Hua-Zhong; Liang, Yong; Shi, Chen-Zhang; Zhu, Qing-Chao; Yang, Jun

    2015-01-01

    AIM: To investigate alternative splicing in vascular endothelial growth factor A (VEGFA), amyloid beta precursor protein (APP), and Numb homolog (NUMB) in colorectal cancer (CRC). METHODS: Real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and PCR-restriction fragment length polymorphism analyses were performed to detect the expression of VEGFA, APP, and NUMB mRNA in 20 CRC tissues and matched adjacent normal tissues, as well as their alternative splicing variants. RESULTS: qRT-PCR analysis revealed that the expression of APP, NUMB, and VEGFA165b mRNA were significantly downregulated, while VEGFA mRNA was upregulated, in CRC tissues (all P < 0.05). PCR-restriction fragment length polymorphism analysis revealed that the expression of VEGFA165a/b in CRC tissues was significantly higher than in adjacent normal tissues (P < 0.05). Compared with adjacent normal tissues, the expression of NUMB-PRRS in CRC tissues was significantly decreased (P < 0.05), and the expression of NUMB-PRRL was increased (P < 0.05). CONCLUSION: Alternative splicing of VEGFA, APP, and NUMB may regulate the development of CRC, and represent new targets for its diagnosis, prognosis, and treatment. PMID:26074693

  5. Novel APP/Aβ mutation K16N produces highly toxic heteromeric Aβ oligomers.

    PubMed

    Kaden, Daniela; Harmeier, Anja; Weise, Christoph; Munter, Lisa M; Althoff, Veit; Rost, Benjamin R; Hildebrand, Peter W; Schmitz, Dietmar; Schaefer, Michael; Lurz, Rudi; Skodda, Sabine; Yamamoto, Raina; Arlt, Sönke; Finckh, Ulrich; Multhaup, Gerd

    2012-07-01

    Here, we describe a novel missense mutation in the amyloid precursor protein (APP) causing a lysine-to-asparagine substitution at position 687 (APP770; herein, referred to as K16N according to amyloid-β (Aβ) numbering) resulting in an early onset dementia with an autosomal dominant inheritance pattern. The K16N mutation is located exactly at the α-secretase cleavage site and influences both APP and Aβ. First, due to the K16N mutation APP secretion is affected and a higher amount of Aβ peptides is being produced. Second, Aβ peptides carrying the K16N mutation are unique in that the peptide itself is not harmful to neuronal cells. Severe toxicity, however, is evident upon equimolar mixture of wt an