WorldWideScience
1

Heterogeneity of human serum amyloid A proteins  

OpenAIRE

Serum amyloid A proteins (SAA), presumed precursors of the tissue amyloid A proteins (AA) characteristic of secondary amyloidosis, have been isolated from the plasma high-density lipoproteins (HDL) of normals after etiocholanolone-induced inflammation and from patients with Wegener's granulomatosis, systemic lupus erythematosis, juvenile rheumatoid arthritis, Waldenstrom's macroglobulinemia, and Goodpasture's syndrome. At least six polymorphic forms of SAA wer identified among the low molecul...

1980-01-01

2

Correlation of persistently high serum amyloid A protein and C-reactive protein concentrations with rapid progression of secondary amyloidosis.  

OpenAIRE

The importance of serum amyloid A protein in the progression of renal failure was studied over three years in 28 patients with secondary (amyloid A type) amyloidosis predominantly due to rheumatoid arthritis. Creatinine clearance, the amount of protein in the urine, and serum amyloid A and C-reactive protein concentrations were determined regularly. Linear regression analysis showed a close correlation between the change in creatinine clearance each year and both serum amyloid A concentration...

Falck, H. M.; Maury, C. P.; Teppo, A. M.; Wegelius, O.

1983-01-01

3

Serum amyloid A protein in amyloidosis, rheumatic, and neoplastic diseases  

International Nuclear Information System (INIS)

Serum levels of amyloid protein A (SAA) have been shown to be elevated in different types of amyloidosis and in rheumatic diseases by radioimmunoassay using 125 iodine labeled AA and anti-AA. SAA levels were elevated in both primary and secondary amyloidosis, but there were highly significant differences between these levels. In heredofamilial amyloid, SAA levels were within normal limits. While the mean SAA level was elevated in persons over 70 years, the fact that some persons in this age group had normal levels suggested that marked elevation after age 70 may be due to occult inflammatory or neoplastic disease. High SAA levels in patients with rheumatoid arthritis correlated, in most cases, with physician evaluation of disease activity and Westergren ESR. SAA levels in patients with systemic lupus erythematosus were lower than those in patients with rheumatoid arthritis, and most patients with degenerative joint disease had normal levels. Very high levels of SAA were found in patients with neoplastic diseases. Patients with carcinoma of the lung and bowel had much higher levels than patients with carcinoma of the breast. Determination of SAA levels may be of value in evaluating different forms of systemic amyloidosis, assessing the activity of rheumatic disease, and screening for occult inflammatory or neoplastic disease

4

Identification of Human Serum Proteins Which Interact With Alzheimer`s Amyloid ?A4 Protein  

Directory of Open Access Journals (Sweden)

Full Text Available Alzheimer`s amyloid ?A4 protein fused with glutathione S-transferase (GST was highly expressed using a strong prokaryotic expression system in Escherichia coli. The expressed protein had expected molecular mass on SDS-PAGE and appeared exclusively immunoreactive with antibody specific for ?A4 epitope. This recombinant protein was purified with a combination of urea solubilization and ion exchange chromatography. To identify the human serum proteins which interact with ?A4, affinity columns were prepared by immobilizing GST- ?A4 and GST respectively. Using the affinity columns and human serum, we have observed an interaction of ?A4 with serum proteins. Two proteins of Mr 45 and 15 kDa were identified on SDS-PAGE to be involved in the interaction. Our demonstration of the ability of ?A4 to interact with serum protein strongly support the notion that such an interaction may underlie with the biological function of ?A4 in vivo.

Golam Sadik

2000-01-01

5

A comparison of serum amyloid A (SAA) synthesis with that of the pentraxins: Serum amyloid P (SAP) and C-reactive protein (CRP)  

International Nuclear Information System (INIS)

Serum amyloid A (SAA) and serum amyloid P (SAP) were detected in cultures of hepatocytes which had been isolated from normal CBA/J mice by the collagenase perfusion technique. SAP production in 24 h cultures was more resistant than SAA and total protein synthesis to inhibition by actinomycin D, but was more sensitive to inhibition by 48 h. However, the production of SAP was more sensitive to cycloheximide than SAA and total protein throughout the 48 hr incubation period. SAP and SAA levels in the culture media were suppressed by treatment of liver cells with 10-6 M of colchicine for 48 h. Inhibition of SAP production by colchicine was the same regardless of culture condition, but the effect of colchicine on SAA synthesis varied according to the presence of serum of monokine. These observations also support the concept that the two amyloid proteins are produced under different regulatory mechanisms. When C-reactive protein (CRP) was not detected in the sera of patients with severe chronic liver diseases, the SAA levels were very low. When CRP was detected, SAA values were within the normal range. Thus, in order to produce SAA, liver cells in these patients not only were viable but also maintained their specialized function

6

Effect of colchicine on the acute phase serum amyloid A protein response and splenic amyloid deposition during experimental murine inflammation  

International Nuclear Information System (INIS)

We investigated the effects of colchicine on the acute phase serum amyloid A protein (SAA) response and splenic amyloid A protein (AA) deposition in CBA/J mice undergoing chronic inflammatory stimulation with silver nitrate (AgNO3), and on accelerated amyloid deposition induced by amyloidenhancing factor (AEF). Colchicine (10 microg daily) significantly lowered splenic AA levels after 25 days of inflammation, as determined by radioimmunoassay. Pretreatment (3 days) with colchicine decreased SAA levels 24 h after AgNO3. It was (unexpectedly) observed that brief pretreatment (12 h) with colchicine augmented the acute phase SAA response to AgNO3 at 24 h. Colchicine stimulated production of both the SAA inducer and lymphocyte-activating factor (LAF) activities of interleukin 1 (IL 1) by macrophages. Decreased SAA levels did not appear to be the mechanism by which colchicine inhibited amyloidosis, since SAA levels fell both in colchicinetreated and control mice after 25 days of inflammation. Colchicine only partially lowered AA deposition after injection of AEF. This effect could be explained by decreased acute phase SAA levels. It is postulated that colchicine inhibits amyloidosis in the pre-deposition period by altering the production of factors (e.g., AEF) required in the deposition phase

7

Serum amyloid A protein (SAA) from mink, horse, and man: a comparative study  

International Nuclear Information System (INIS)

Serum amyloid A protein (SAA) was isolated from mink, horse, and human serum by ultracentrifugation and gel filtration and characterized by two-dimensional gel electrophoresis, Western blotting followed by autoradiography and N-terminal amino acid analysis. SAA was found in similar quantities in the high density lipoprotein (HDL) fraction of serum from a patient suffering from systemic juvenile rheumatoid arthritis (JRA) and mink stimulated with lipopolysaccharide (LPS), and in somewhat smaller quantities in serum from horses stimulated with Escherichia coli cultures. Only very small quantities were present in normal human controls and not detectable in normal mink and horse. Striking similarities were found between human and mink SAA with respect to molecular weight, isolectric point and degree of heterogeneity, while the molecular weight, isolectric point and degree of heterogeneity, while the molecular weight of horse SAA seemed to be somewhat lower, and no obvious heterogeneity could be demonstrated in this protein using two-dimensional gel electrophoresis. Immunologic cross-reactivity between SAA from the three species was not found. In contrast to human and horse HDL, mink HDL was found not to contain apoA-II and only minute amounts of apoC proteins. Normal horse HDL also contained additional apoproteins not present in HDL from the other species. N-terminal amino acids analysis of SAA from mink and horse demonstrated the same similarity with the corresponding AA same similarity with the corresponding AA protein as previously reported for human SAA/AA

8

Solid-phase immunoradiometric assay for serum amyloid A protein using magnetisable cellulose particles  

International Nuclear Information System (INIS)

An immunoradiometric assay for human serum amyloid A protein (SAA) was developed using magnetisable cellulose particles as the solid phase. Rabbit antiserum to SAA was raised by immunization with SAA isolated from acute-phase serum by gel filtration in formic acid. The antiserum was rendered monospecific for SAA by solid-phase immunoabsorption with normal human serum, which contains only traces of SAA, and some was coupled covalently to the cellulose particles. Immunopurified anti-SAA antibodies were isolated from the monospecific anti-SAA serum by binding to, and elution from insolubilized acute-phase serum and were radiolabelled with 125I. The assay was calibrated with an acute phase serum which contained 6000 times more SAA than normal sera with the lowest detectable level of SAA, and an arbitrary value of 6000 U/l was assigned to this standard. Sera were tested in the native, undenatured state and there was no increase in SAA immunoreactivity following alkali treatment or heating. The assay range was from 1-2000 U/l so that all SAA levels above 6 U/l could be measured on a single (1:6) dilution of serum. The intra- and interassay coefficients of variation were 11.7 and 15.0% respectively. Among 100 healthy normal subjects (50 male, 50 female) the median SAA level was 9 U/l, range <1-100, with 93% below 20 U/l and only 2% below the lower limit of sensitivity of the assay (1 U/l). (Auth.)

9

Goodpasture antigen-binding protein/ceramide transporter binds to human serum amyloid P-component and is present in brain amyloid plaques.  

Science.gov (United States)

Serum amyloid P component (SAP) is a non-fibrillar glycoprotein belonging to the pentraxin family of the innate immune system. SAP is present in plasma, basement membranes, and amyloid deposits. This study demonstrates, for the first time, that the Goodpasture antigen-binding protein (GPBP) binds to human SAP. GPBP is a nonconventional Ser/Thr kinase for basement membrane type IV collagen. Also GPBP is found in plasma and in the extracellular matrix. In the present study, we demonstrate that GPBP specifically binds SAP in its physiological conformations, pentamers and decamers. The START domain in GPBP is important for this interaction. SAP and GPBP form complexes in blood and partly colocalize in amyloid plaques from Alzheimer disease patients. These data suggest the existence of complexes of SAP and GPBP under physiological and pathological conditions. These complexes are important for understanding basement membrane, blood physiology, and plaque formation in Alzheimer disease. PMID:22396542

Mencarelli, Chiara; Bode, Gerard H; Losen, Mario; Kulharia, Mahesh; Molenaar, Peter C; Veerhuis, Robert; Steinbusch, Harry W M; De Baets, Marc H; Nicolaes, Gerry A F; Martinez-Martinez, Pilar

2012-04-27

10

Goodpasture Antigen-binding Protein/Ceramide Transporter Binds to Human Serum Amyloid P-Component and Is Present in Brain Amyloid Plaques*  

Science.gov (United States)

Serum amyloid P component (SAP) is a non-fibrillar glycoprotein belonging to the pentraxin family of the innate immune system. SAP is present in plasma, basement membranes, and amyloid deposits. This study demonstrates, for the first time, that the Goodpasture antigen-binding protein (GPBP) binds to human SAP. GPBP is a nonconventional Ser/Thr kinase for basement membrane type IV collagen. Also GPBP is found in plasma and in the extracellular matrix. In the present study, we demonstrate that GPBP specifically binds SAP in its physiological conformations, pentamers and decamers. The START domain in GPBP is important for this interaction. SAP and GPBP form complexes in blood and partly colocalize in amyloid plaques from Alzheimer disease patients. These data suggest the existence of complexes of SAP and GPBP under physiological and pathological conditions. These complexes are important for understanding basement membrane, blood physiology, and plaque formation in Alzheimer disease. PMID:22396542

Mencarelli, Chiara; Bode, Gerard H.; Losen, Mario; Kulharia, Mahesh; Molenaar, Peter C.; Veerhuis, Robert; Steinbusch, Harry W. M.; De Baets, Marc H.; Nicolaes, Gerry A. F.; Martinez-Martinez, Pilar

2012-01-01

11

Calcium-dependent and -independent binding of the pentraxin serum amyloid P component to glycosaminoglycans and amyloid proteins : enhanced binding at slightly acid pH  

DEFF Research Database (Denmark)

Serum amyloid P component (SAP), a member of the pentraxin family of proteins, binds calcium-dependently to several ligands including glycosaminoglycans (GAG's). We have investigated the influence of pH on the Ca2(+)-dependent binding of SAP to solid phase GAG's and amyloid fibril proteins (AA and beta2M) by ELISA. An increase in the dose-dependent binding of SAP to heparan sulfate, AA-protein and beta2M was observed as the pH decreased from 8.0 to 5.0. Furthermore, a lower, but significant Ca2(+)-independent binding of SAP to heparan sulfate, dermatan sulfate, AA protein and the amyloid precursor protein beta2M was observed. This binding was also enhanced at slightly acid pH, most pronounced at pH 5.0. The results of this study indicate that SAP can exhibit both Ca2(+)-dependent and -independent binding to ligands involved in amyloid fibril formation and that the binding is enhanced under conditions of slightly lowered pH.

Danielsen, B; SØrensen, I J

1997-01-01

12

Evaluation of Sialic Acid and Acute Phase Proteins (Haptoglobin and Serum Amyloid A in Clinical and Subclinical Bovine Mastitis  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was conducted to evaluate the concentrations of sialic acids (total, lipid bound and protein bound and their correlation with acute phase proteins (haptoglobin and serum amyloid A in clinical and subclinical mastitis of cattle. Thirty subclinical mastitic cows with positive California mastitis test (CMT test and no clinical signs of mastitis, 10 clinical mastitic cows and 10 healthy cows with negative CMT test and normal somatic cell count were selected. Milk and blood samples were collected after confirmation of clinical and subclinical mastitis by somatic cell count and bacterial identification. Serum haptoglobin (Hp, serum amyloid A (SAA, total sialic acid (TSA, lipid bound sialic acid (LBSA and protein bound sialic acid (PBSA were measured by validated standard methods. Haptoglobin and SAA increased significantly in both types of mastitis compared with control group (P<0.001. However, the ratio of HP/SAA was significantly different from the control group only in clinical mastitis. The results showed that TSA and LBSA were significantly different in control group compared with clinical and subclinical mastitis (P<0.001. Protein bound sialic acid did not change in subclinical mastitis in comparison with control group (P=0.86. There was positive correlation between LBSA and PBSA in clinical mastitis (r=0.72, P=0.02 whereas significant negative correlation was observed between LBSA and PBSA in subclinical mastitis (r=-0.62, P<0.001. Results also showed no correlation between Hp and SAA with each other or with any other parameters in study groups.

S. Nazifi*, M. Haghkhah1, Z. Asadi, M. Ansari-Lari2, M. R. Tabandeh3, Z. Esmailnezhad and M. Aghamiri

2011-01-01

13

Relationship between urinary sialylated saccharides, serum amyloid A protein, and C-reactive protein in rheumatoid arthritis and systemic lupus erythematosus.  

OpenAIRE

The urinary excretion of sialic-acid-containing oligosaccharides, total sialic acid, serum amyloid A protein (SAA), and C-reactive protein (CRP) has been studied in 48 patients with rheumatoid arthritis (RA) and in 17 patients with systemic lupus erythematosus (SLE). Linear regression analysis revealed a close positive correlation between serum SAA and CRP levels in both RA (r = 0.71, p less than 0.001) and SLE (r = 0.86, p less than 0.001). The urinary excretion of sialyl lactose showed a po...

Maury, C. P.; Teppo, A. M.; Wegelius, O.

1982-01-01

14

Acute-phase protein serum amyloid A3 is a novel paracrine coupling factor that controls bone homeostasis.  

Science.gov (United States)

Serum amyloid A (A-SAA/Saa3) was shown before to affect osteoblastic metabolism. Here, using RT-quantitative PCR and/or immunoblotting, we show that expression of mouse Saa3 and human SAA1 and SAA2 positively correlates with increased cellular maturation toward the osteocyte phenotype. Expression is not detected in C3H10T1/2 embryonic fibroblasts but is successively higher in preosteoblastic MC3T3-E1 cells, late osteoblastic MLO-A5 cells, and MLO-Y4 osteocytes, consistent with findings using primary bone cells from newborn mouse calvaria. Recombinant Saa3 protein functionally inhibits osteoblast differentiation as reflected by reductions in the expression of osteoblast markers and decreased mineralization in newborn mouse calvaria. Yet, Saa3 protein enhances osteoclastogenesis in mouse macrophages/monocytes based on the number of multinucleated and tartrate-resistant alkaline phosphatase-positive cells and Calcr mRNA expression. Depletion of Saa3 in MLO osteocytes results in the loss of the mature osteocyte phenotype. Recombinant osteocalcin, which is reciprocally regulated with Saa3 at the osteoblast/osteocyte transition, attenuates Saa3 expression in MLO-Y4 osteocytes. Mechanistically, Saa3 produced by MLO-Y4 osteocytes is integrated into the extracellular matrix of MC3T3-E1 osteoblasts, where it associates with the P2 purinergic receptor P2rx7 to stimulate Mmp13 expression via the P2rx7/MAPK/ERK/activator protein 1 axis. Our data suggest that Saa3 may function as an important coupling factor in bone development and homeostasis.-Thaler, R., Sturmlechner, I., Spitzer, S., Riester, S. M., Rumpler, M., Zwerina, J., Klaushofer, K., van Wijnen, A. J., and Varga, F. Acute-phase protein serum amyloid A3 is a novel paracrine coupling factor that controls bone homeostasis. PMID:25491310

Thaler, Roman; Sturmlechner, Ines; Spitzer, Silvia; Riester, Scott M; Rumpler, Monika; Zwerina, Jochen; Klaushofer, Klaus; van Wijnen, Andre J; Varga, Franz

2014-12-01

15

Nanophotonics of protein amyloids  

Science.gov (United States)

Technological breakthroughs in the super-resolution optical imaging techniques have enriched our current understanding of a range of biological systems and biomolecular processes at the nanoscopic spatial resolution. Protein amyloids are an important class of ordered protein assemblies consisting of misfolded proteins that are implicated in a wide range of devastating human diseases. In order to decipher the structural basis of the supramolecular protein assembly in amyloids and their detrimental interactions with the cell membranes, it is important to employ high-resolution optical imaging techniques. Additionally, amyloids could serve as novel biological nanomaterials for a variety of potential applications. In this review, we summarize a few examples of the utility of near-field scanning optical imaging methodologies to obtain a wealth of structural information into the nanoscale amyloid assembly. Although the near-field technologies were developed several decades ago, it is only recently that these methodologies are being applied and adapted for amyloid research to yield novel information pertaining to the exciting nanoscopic world of protein aggregates. We believe that the account on the nanophotonics of amyloids described in this review will be useful for the future studies on the biophysics of amyloids.

Bhattacharya, Mily; Mukhopadhyay, Samrat

2014-04-01

16

The amyloid precursor protein: beyond amyloid  

OpenAIRE

Abstract The amyloid precursor protein (APP) takes a central position in Alzheimer's disease (AD) pathogenesis: APP processing generates the ?-amyloid (A?) peptides, which are deposited as the amyloid plaques in brains of AD individuals; Point mutations and duplications of APP are causal for a subset of early onset of familial Alzheimer's disease (FAD). Not surprisingly, the production and pathogenic effect of A? has been the central focus in AD field. Nevertheless, the biologica...

Zheng Hui; Koo Edward H

2006-01-01

17

The diagnostic role of human epididymis protein 4 and serum amyloid-A in early-stage endometrial cancer patients.  

Science.gov (United States)

The aim of this study was to evaluate the prognostic and predictive efficacy of the human epididymis secretory protein 4 (HE4) and serum amyloid-A (S-AA) together with the other tumor markers (CA 125, CA 15-3, CEA, and CA 19-9) in endometrial cancer patients. The study group consisted of 64 patients with defined stage and grade of endometrial cancer and 60 women with benign uterine diseases. Thirty-four healthy women were defined as the control group. Fasting blood samples were collected prior to surgery and tumor marker levels were determined in blood samples by E170 autoanalyzer. S-AA concentrations were measured by particle-enhanced immunonephelometry. Preoperative serum HE4 and S-AA levels were significantly higher in endometrial cancer patients than in controls, whereas the other measured parameters were not significantly different. Serum levels of HE4 were related to both the stage and grade of tumor. The best cutoff point for HE4 was determined to be 59.7 pmol/L; with 75 % sensitivity and 65.5 % specificity. For S-AA, the cutoff point was 8.8 U/mL, with 68.7 % sensitivity and 58.6 % specificity. The combination of HE4, CA 125, CEA, and S-AA raised the sensitivity to 84 %. Preoperative measurement of serum HE4 and S-AA may be of help in early detection of endometrial cancer. Preoperative screening with these markers may provide important information about the patient's outcome and prognosis. PMID:23640061

Omer, Beyhan; Genc, Sema; Takmaz, Ozguc; Dirican, Ahmet; Kusku-Kiraz, Zeynep; Berkman, Sinan; Gurdol, Figen

2013-10-01

18

Calumenin interacts with serum amyloid P component.  

DEFF Research Database (Denmark)

We recently reported the identification of human calumenin, a novel Ca(2+) binding, transformation-sensitive and secreted protein [Vorum et al. (1998) Biochim. Biophys. Acta 1386, 121-131; Vorum et al. (1999) Exp. Cell Res. 248, 473-481] belonging to the family of multiple EF-hand proteins of the secretory pathway that include reticulocalbin, ERC-55, Cab45 and crocalbin. In order to further investigate the extracellular functions of calumenin we immobilized the recombinant protein to a column. After application of a placental tissue extract we were able to elute one protein that interacts with calumenin in the presence of Ca(2+). Amino acid sequencing identified this protein as serum amyloid P component (SAP). Furthermore, we verified and characterized the calumenin-SAP interaction by the surface plasmon resonance technique. The findings indicate that calumenin may participate in the immunological defense system and could be involved in the pathological process of amyloidosis that leads to formation of amyloid deposits seen in different types of tissues. Udgivelsesdato: 2000-Jan-14

Vorum, H; Jacobsen, Christian

2000-01-01

19

An in vitro study on neuroprotective effects of serum containing Gengnianchun decoction and its main monomers against amyloid beta protein-induced cellular toxicity  

OpenAIRE

Obiective: To observe the effects of serum containing Gengnianchun (GNC) decoction, a compound traditional Chinese herbal medicine, and its monomers (paeoniflorin, berberine, timosaponin A-? and icariin) on neurotoxicity in PC12 cells induced by amyloid beta-protein (A?).?Methods: Injury of PC12 cells was induced by in incubating with A?25-35 in vitro.? Ovariectomized rats were intragastrically administered with GNC decoction twice daily for 5 days and then sera were obtained. Differe...

Wang, Wen-jun

2010-01-01

20

Diagnostic utility and limitations of glutamine synthetase and serum amyloid-associated protein immunohistochemistry in the distinction of focal nodular hyperplasia and inflammatory hepatocellular adenoma.  

Science.gov (United States)

Inflammatory hepatocellular adenoma can show overlapping histological features with focal nodular hyperplasia, including inflammation, fibrous stroma, and ductular reaction. Expression of serum amyloid-associated protein in inflammatory hepatocellular adenoma and map-like pattern of glutamine synthetase in focal nodular hyperplasia can be helpful in this distinction, but the pitfalls and limitations of these markers have not been established. Morphology and immunohistochemistry were analyzed in 54 inflammatory hepatocellular adenomas, 40 focal nodular hyperplasia, and 3 indeterminate lesions. Morphological analysis demonstrated that nodularity, fibrous stroma, dystrophic blood vessels, and ductular reaction were more common in focal nodular hyperplasia, while telangiectasia, hemorrhage, and steatosis were more common in inflammatory hepatocellular adenoma, but there was frequent overlap of morphological features. The majority of inflammatory hepatocellular adenomas demonstrated perivascular and/or patchy glutamine synthetase staining (73.6%), while the remaining cases had diffuse (7.5%), negative (3.8%), or patchy pattern of staining (15%) that showed subtle differences from the classic map-like staining pattern and was designated as pseudo map-like staining. Positive staining for serum amyloid-associated protein was seen in the majority of inflammatory hepatocellular adenomas (92.6%) and in the minority of focal nodular hyperplasia (17.5%). The glutamine synthetase staining pattern was map-like in 90% of focal nodular hyperplasia cases, with the remaining 10% of cases showing pseudo map-like staining. Three cases were labeled as indeterminate and showed focal nodular hyperplasia-like morphology but lacked map-like glutamine synthetase staining pattern; these cases demonstrated a patchy pseudo map-like glutamine synthetase pattern along with the expression of serum amyloid-associated protein. Our results highlight the diagnostic errors that can be caused by variant patterns of staining with glutamine synthetase and serum amyloid-associated protein in inflammatory hepatocellular adenoma and focal nodular hyperplasia. PMID:23807780

Joseph, Nancy M; Ferrell, Linda D; Jain, Dhanpat; Torbenson, Michael S; Wu, Tsung-Teh; Yeh, Matthew M; Kakar, Sanjay

2014-01-01

21

Human serum amyloid genes--molecular characterization  

International Nuclear Information System (INIS)

Three clones containing human genes for serum amyloid A protein (SAA) have been isolated and characterized. Each of two clones, GSAA 1 and 2 (of 12.8 and 15.9 kilobases, respectively), contains two exons, accouting for amino acids 12-58 and 58-103 of mature SAA; the extreme 5' termini and 5' untranslated regions have not yet been defined but are anticipated to be close based on studies of murine SAA genes. Initial amino acid sequence comparisons show 78/89 identical residues. At 4 of the 11 discrepant residues, the amino acid specified by the codon is the same as the corresponding residue in murine SAA. Identification of regions containing coding regions has permitted use of selected subclones for blot hybridization studies of larger human SAA chromosomal gene organization. The third clone, GSAA 3 also contains SAA coding information by DNA sequence analysis but has a different organization which has not yet been fully described. We have reported the isolation of clones of human DNA hybridizing with pRS48 - a plasmid containing a complementary DNA (cDNA) clone for murine serum amyloid A (SAA; 1, 2). We now present more detailed data confirming the identity and defining some of the organizational features of these clones

22

Investigating interactions of the pentraxins serum amyloid P component and C-reactive protein by mass spectrometry.  

Science.gov (United States)

The oligomeric state of human SAP (serum amyloid P component) in the absence and presence of known ligands has been investigated using nanoelectrospray ionization MS. At pH 8.0, in the absence of Ca2+, SAP has been shown to consist of pentameric and decameric forms. In the presence of physiological levels of Ca2+, SAP was observed to exist primarily as a pentamer, reflecting its in vivo state. dAMP was shown not only to promote decamerization, but also to lead to decamer stacking involving up to 30 monomers. A mechanism for this finding is proposed. CRP (C-reactive protein), a pentraxin closely related to SAP, exists as a pentamer in the presence or absence of Ca2+. Pentamers of CRP and SAP were shown to form mixed decamers in Ca2+-free buffer; however, in the presence of Ca2+, this interaction was not observed. Furthermore, no exchange of monomeric subunits was observed between the SAP and CRP oligomers, suggesting a remarkable stability of the individual pentameric complexes. PMID:12892563

Aquilina, J Andrew; Robinson, Carol V

2003-01-01

23

Janus faces of amyloid proteins in neuroinflammation.  

Science.gov (United States)

Amyloid forming molecules are generally considered harmful. In Alzheimer's Disease two amyloid molecules A? A4 and tau vie for consideration as the main pathogenic culprit. But molecules obey the laws of chemistry and defy the way we categorize them as humans with our well-known proclivities to bias in our reasoning. We have been exploring the brains of multiple sclerosis patients to identify molecules that are associated with protection from inflammation and degeneration. In 2001 we noted that aB crystallin (cryab) was the most abundant transcript found in MS lesions, but not in healthy brains. Cryab can reverse paralysis and attenuate inflammation in several models of inflammation including experimental autoimmune encephalomyelitis (EAE), and various models of ischemia. Cryab is an amyloid forming molecule. We have identified a core structure common to many amyloids including amyloid protein A? A4, tau, amylin, prion protein, serum amyloid protein P, and cryab. The core hexapeptide structure is highly immune suppressive and can reverse paralysis in EAE when administered systemically. Administration of this amyloid forming hexapeptide quickly lowers inflammatory cytokines in plasma like IL-6 and IL-2. The hexapeptide bind a set of proinflammatory mediators in plasma, including acute phase reactants and complement components. The beneficial properties of amyloid forming hexapeptides provide a potential new therapeutic direction. These experiments indicate that amyloid forming molecules have Janus faces, providing unexpected benefit for neuroinflammatory conditions. PMID:24711007

Steinman, Lawrence; Rothbard, Jonathan B; Kurnellas, Michael P

2014-07-01

24

Serum amyloid A and C-reactive protein positive nodule in alcoholic liver cirrhosis, hard to make definite diagnosis.  

Science.gov (United States)

We describe a case of serum amyloid A (SAA) and C-reactive protein (CRP) positive nodule detected by immunohistochemical analysis in a 37-year-old woman with alcohol-related cirrhosis. Imaging studies at first admission pointed to hepatocellular carcinoma (HCC), a dysplastic nodule, an inflammatory pseudotumor or focal nodular hyperplasia (FNH). Ultrasonography-guided biopsy in Segment 2 showed minimal atypical changes, except for a slight increase in cell density and micronodular cirrhosis in the non-nodular portion. gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging carried out after a year and a half revealed hypervascularity in the arterial phase and isointensity in the hepatobiliary phase. Three years thereafter, however, the imaging displayed a change from isointensity to a defect in the hepatobiliary phase, and the nodule demonstrated minimal histological atypia. Immunohistochemical staining of the nodule was positive for SAA, CRP, liver fatty acid-binding protein and glutamine synthetase, but negative for ?-catenin, heat shock protein 70 and Glypican 3. Organic anion transporter (OATP)8 staining was weaker in the nodule than in the non-nodular portion of the alcohol-related micronodular cirrhosis. The nodule was diagnosed as an SAA and CRP positive nodule, and HCC was ruled out. Despite the change from isointensity to a defect in the hepatobiliary phase, no evidence of HCC was found in the biopsy specimen. The change may be explained more by the weak OATP8 staining compared with that of alcohol-related liver cirrhosis than by malignant transformation into HCC. PMID:23607539

Kim, Soo Ryang; Kondo, Fukuo; Otono, Yumi; Imoto, Susumu; Ando, Kenji; Hirakawa, Makoto; Fukuda, Katsumi; Sasaki, Madoka; Kim, Soo Ki; Komaki, Takamitsu; Tsuchida, Shinobu; Kobayashi, Sawako; Matsuoka, Toshiyuki; Kudo, Masatoshi

2014-05-01

25

Diagnostic radionuclide imaging of amyloid: biological targeting by circulating human serum amyloid P component  

International Nuclear Information System (INIS)

The specific molecular affinity of the normal plasma protein, serum amyloid P component (SAP), for all known types of amyloid fibrils was used to develop a new general diagnostic method for in-vivo radionuclide imaging of amyloid deposits. After intravenous injection of 123I-labelled purified human SAP there was specific uptake into amyloid deposits in all affected patients, 7 with systematic AL amyloid, 5 with AA amyloid, and 2 with ?2M amyloid, in contrast to the complete absence of any tissue localisation in 5 control subjects. Distinctive high-resolution scintigraphic images, even of minor deposits in the carpal regions, bone marrow, or adrenals, were obtained. This procedure should yield much information on the natural history and the management of amyloidosis, the presence of which has hitherto been confirmed only by biopsy. Clearance and metabolic studies indicated that, in the presence of extensive amyloidosis, the rate of synthesis of SAP was greatly increased despite maintenance of normal plasma levels. Futhermore, once localised to amyloid deposits the 123I-SAP persisted for long periods and was apparently protected from its normal rapid degradation. These findings shed new light on the pathophysiology of amyloid and may have implications for therapeutic strategies based upon specific molecular targeting with SAP. (author)

26

Up-regulation of MUC2 mucin expression by serum amyloid A3 protein in mouse colonic epithelial cells.  

Science.gov (United States)

Serum amyloid A (SAA) proteins are acute-phase proteins and are classified into multiple isoforms; however, the biological functions of each SAA isoform are not fully understood. In this study, to clarify the roles of SAA3 in the intestine, we characterized mRNA expression in mouse colonic epithelial CMT-93 cells treated with rotavirus, Toxoplasma, Staphylococcus aureus, and Escherichia coli, as well as lipopolysaccharide (LPS) and recombinant murine SAAs (rSAAs). E. coli together with LPS, but not the other pathogens, enhanced SAA3 mRNA expression. The mRNA expression of SAA3 by dead E. coli was higher than that by living E. coli, and the mRNA expression by E. coli and LPS increased in a dose-dependent manner. In contrast, mRNA expressions of SAA1 and/or SAA2 were not stimulated by any of the treatments. In comparisons of cell treatments with rSAA1 or rSAA3, rSAA3 significantly up-regulated the mRNA expression of mucin 2 (MUC2), a major component of the mucus layer of the intestines that acts as an epithelial cell barrier against pathogens, while MUC2 mRNA expression was not significantly increased by E. coli and LPS. Furthermore, treatment with rSAAs intensively induced tumor necrosis factor-? mRNA expression. These results suggest that SAA3 plays a role in host innate immunity in the colon by up-regulating MUC2 mucin production, which builds a physiological barrier of colonic epithelia against bacterial invasion. PMID:24694941

Shigemura, Hiroaki; Ishiguro, Naotaka; Inoshima, Yasuo

2014-07-01

27

Serum insulin-like growth factor-I, iron, C-reactive protein, and serum amyloid A for prediction of outcome in dogs with pyometra.  

Science.gov (United States)

Pyometra, accumulation of pus in the uterus, is a bacterial infection that frequently initiates systemic inflammation. The disease may have lethal consequences when the systemic effects are severe or complications occur. Markers for identifying high-risk patients and predicting outcome are therefore in high demand. The objective of this study was to measure serum concentrations of insulin-like growth factor-I (IGF-I), iron, C-reactive protein (CRP), and serum amyloid A (SAA) in bitches with pyometra and to explore the possible value of these variables for detection of increased morbidity. In total, 31 bitches were diagnosed with pyometra and destined for surgical treatment (ovariohysterectomy) and 17 healthy bitches were included in the study. Concentrations of IGF-I and iron were lower in the pyometra group (mean concentration 221.2 ± 22.5 ng/mL and 16.9 ± 1.6 ?mol/L, respectively) compared with the healthy control group (mean concentration 366.7 ± 46.2 ng/mL and 38.1 ± 2.7 ?mol/L, respectively). In contrast, concentrations of CRP and SAA were significantly higher in bitches with pyometra (mean concentrations 212.9 ± 17.3 mg/L and 119.9 ± 8.5 mg/L, respectively) compared with the control group (measured by duration of postoperative hospitalization. In conclusion, IGF-I and iron concentrations were decreased in pyometra, whereas SAA and CRP concentrations were increased in the disease. Although unspecific, measurement of these variables may be valuable as adjunctive markers for prognosis in cases of pyometra. PMID:24661434

Jitpean, Supranee; Holst, Bodil Ström; Höglund, Odd V; Pettersson, Ann; Olsson, Ulf; Strage, Emma; Södersten, Fredrik; Hagman, Ragnvi

2014-07-01

28

Investigating interactions of the pentraxins serum amyloid P component and C-reactive protein by mass spectrometry.  

OpenAIRE

The oligomeric state of human SAP (serum amyloid P component) in the absence and presence of known ligands has been investigated using nanoelectrospray ionization MS. At pH 8.0, in the absence of Ca2+, SAP has been shown to consist of pentameric and decameric forms. In the presence of physiological levels of Ca2+, SAP was observed to exist primarily as a pentamer, reflecting its in vivo state. dAMP was shown not only to promote decamerization, but also to lead to decamer stacking involving up...

Aquilina, Ja; Robinson, Cv

2003-01-01

29

Kinetics of human serum amyloid A  

International Nuclear Information System (INIS)

In order to better understand the pathogenetic role of serum amyloid A (SAA) we studied the kinetics of 131I radiolabelled pure SAA, extracted from 400 ml serum of a human volunteer. 50 microCi of 131I SAA and 15 microCi 125I labelled sodium iodide were administered i.v. on two occasions at 6 month intervals. Serum and plasma samples were collected at 10-20 min intervals x 10, then once daily x 10; lymphocytes were separated from monocytes and granulocytes. Counts per minute of 131I and 125I were measured in each sample in the serum, in serum precipitates resulting after addition of a rabbit anti-SAA antibody and of TCA and in various cell subpopulations as well as in the whole urine and TCA precipitated urine from each micturition. The 131I disappearance curves from the plasma and serum precipitates were semilogarithmically plotted; cumulative 131I cpm in plasma, cells and urine at various intervals were determined. Body scanning was performed at 2, 16, and 48 h. The results of the two experiments were very similar. The curve of 131I SAA in plasma TCA precipitates indicated the existence of 4 compartments likely due to uptake of 131I SAA by some plasma proteins, circulating cells and other tissues; later release from tissues started at 6 h. The 131I SAA half-life time in these compartments was found to be 35, 170, 255, and 550 min, respectively. Tissue bindin, and 550 min, respectively. Tissue binding of 131I was also suggested by a rising of the 125I:131I ratio with time and by a 26% release of 131I in the urine at 15 h which could not account for its plasma disappearance. Scanning, except for 131I uptake in the spleen at 2 h likely due to blood activity, showed no organ concentration. 92% of the injected 131I was found in the urine but only 6.2% of 131I SAA was accounted for in urine precicipitates

30

The porcine acute phase response to infection with Actinobacillus pleuropneumoniae. Haptoglobin, C-reactive protein, major acute phase protein and serum amyloid a protein are sensitive indicators of infection  

DEFF Research Database (Denmark)

In an experimental infection model mimicking acute Actinobacillus pleuropneumoniae (Ap) infection in swine (Sus scrofa) by aerosol inoculation, the development of a number of typical clinical signs was accompanied by a prototypic acute phase reaction encompassing fever and an acute phase protein response peaking at around 2 days after infection. Haptoglobin, C-reactive protein (CRP), and major acute phase protein (MAP) responded with large increases in serum levels, preceding the development of specific antibodies by 4-5 days. Serum amyloid A protein (SAA) was also strongly induced. The increase, kinetics of induction and normalization were different between these proteins. It is concluded that experimental Ap-infection by the aerosol route induces a typical acute phase reaction in the pig, and that pig Hp, CRP, MAP, and SAA are major acute phase reactants. These findings indicate the possibility of using one or more of these reactants for the nonspecific surveillance of pig health status.

Heegaard, Peter M. H.; Klausen, Joan

1998-01-01

31

The porcine acute phase response to infection with Actinobacillus pleuropneumoniae. Haptoglobin, C-reactive protein, major acute phase protein and serum amyloid A protein are sensitive indicators of infection.  

Science.gov (United States)

In an experimental infection model mimicking acute Actinobacillus pleuropneumoniae (Ap) infection in swine (Sus scrofa) by aerosol inoculation, the development of a number of typical clinical signs was accompanied by a prototypic acute phase reaction encompassing fever and an acute phase protein response peaking at around 2 days after infection. Haptoglobin, C-reactive protein (CRP), and major acute phase protein (MAP) responded with large increases in serum levels, preceding the development of specific antibodies by 4-5 days. Serum amyloid A protein (SAA) was also strongly induced. The increase, kinetics of induction and normalization were different between these proteins. It is concluded that experimental Ap-infection by the aerosol route induces a typical acute phase reaction in the pig, and that pig Hp, CRP, MAP, and SAA are major acute phase reactants. These findings indicate the possibility of using one or more of these reactants for the nonspecific surveillance of pig health status. PMID:9629669

Heegaard, P M; Klausen, J; Nielsen, J P; González-Ramón, N; Piñeiro, M; Lampreave, F; Alava, M A

1998-02-01

32

Serum amyloid P component scintigraphy in familial amyloid polyneuropathy: regression of visceral amyloid following liver transplantation  

International Nuclear Information System (INIS)

Familial amyloid polyneuropathy (FAP) associated with transthyretin (TTR) mutations is the commonest type of hereditary amyloidosis. Plasma TTR is produced almost exclusively in the liver and orthotopic liver transplantation is the only available treatment, although the clinical outcome varies. Serum amyloid P component (SAP) scintigraphy is a method for identifying and quantitatively monitoring amyloid deposits in vivo, but it has not previously been used to study the outcome of visceral amyloid deposits in FAP following liver transplantation. Whole body scintigraphy following injection of iodine-123 labelled SAP was performed in 17 patients with FAP associated with TTR Met30 and in five asymptomatic gene carriers. Follow-up studies were performed in ten patients, eight of whom had undergone orthotopic liver transplantation 1-5 years beforehand. There was abnormal uptake of 123I-SAP in all FAP patients, including the kidneys in each case, the spleen in five cases and the adrenal glands in three cases. Renal amyloid deposits were also present in three of the asymptomatic carriers. Follow-up studies 1-5 years after liver transplantation showed that there had been substantial regression of the visceral amyloid deposits in two patients and modest improvement in three cases. The amyloid deposits were unchanged in two patients. In conclusion, 123I-SAP scintigraphy identified unsuspected visceral amyloid in each patient with FAP due to TTR Met30. The uh patient with FAP due to TTR Met30. The universal presence of renal amyloid probably underlies the high frequency of renal failure that occurs in FAP following liver transplantation. The variable capacity of patients to mobilise amyloid deposits following liver transplantation may contribute to their long-term clinical outcome. (orig.)

33

Serum amyloid P component scintigraphy in familial amyloid polyneuropathy: regression of visceral amyloid following liver transplantation  

Energy Technology Data Exchange (ETDEWEB)

Familial amyloid polyneuropathy (FAP) associated with transthyretin (TTR) mutations is the commonest type of hereditary amyloidosis. Plasma TTR is produced almost exclusively in the liver and orthotopic liver transplantation is the only available treatment, although the clinical outcome varies. Serum amyloid P component (SAP) scintigraphy is a method for identifying and quantitatively monitoring amyloid deposits in vivo, but it has not previously been used to study the outcome of visceral amyloid deposits in FAP following liver transplantation. Whole body scintigraphy following injection of iodine-123 labelled SAP was performed in 17 patients with FAP associated with TTR Met30 and in five asymptomatic gene carriers. Follow-up studies were performed in ten patients, eight of whom had undergone orthotopic liver transplantation 1-5 years beforehand. There was abnormal uptake of {sup 123}I-SAP in all FAP patients, including the kidneys in each case, the spleen in five cases and the adrenal glands in three cases. Renal amyloid deposits were also present in three of the asymptomatic carriers. Follow-up studies 1-5 years after liver transplantation showed that there had been substantial regression of the visceral amyloid deposits in two patients and modest improvement in three cases. The amyloid deposits were unchanged in two patients. In conclusion, {sup 123}I-SAP scintigraphy identified unsuspected visceral amyloid in each patient with FAP due to TTR Met30. The universal presence of renal amyloid probably underlies the high frequency of renal failure that occurs in FAP following liver transplantation. The variable capacity of patients to mobilise amyloid deposits following liver transplantation may contribute to their long-term clinical outcome. (orig.) With 2 figs., 2 tabs., 22 refs.

Rydh, A.; Hietala, S.O.; Aahlstroem, K.R. [Department of Diagnostic Radiology, University Hospital of Northern Sweden, Umeaa (Sweden); Suhr, O. [Department of Internal Medicine, University Hospital of Northern Sweden, Umeaa (Sweden); Pepys, M.B.; Hawkins, P.N. [Immunological Medicine Unit, Department of Medicine, Imperial College School of Medicine, London (United Kingdom)

1998-07-01

34

Binding of complement proteins C1q and C4bp to serum amyloid P component (SAP) in solid contra liquid phase.  

DEFF Research Database (Denmark)

Serum amyloid P component (SAP), a member of the conserved pentraxin family of plasma proteins, binds calcium dependently to its ligands. The authors investigated SAPs interaction with the complement proteins C4b binding protein (C4bp) and C1q by ELISA, immunoelectrophoresis and electron microscopy. Binding of these proteins to SAP was demonstrated when SAP was immobilized using F(ab')2 anti-SAP, but not when SAP reacted with these proteins in liquid phase; thus the binding to human SAP was markedly phase state dependent. Presaturation of solid phase SAP with heparin, which binds SAP with high affinity, did not interfere with the subsequent binding of C4bp or C1q to SAP. In contrast, collagen I and IV showed partial competition with the binding of C1q to SAP. Using fresh serum, immobilized native SAP bound C4bp whereas binding of C1q/C1 could not be demonstrated. Altogether the results indicate that firm binding of C1q and C4bp to SAP requires that SAP is presented on a solid phase, that C1q and C4bp react with sites distinct from the heparin binding site, and that C1q and collagen I share binding sites on SAP. Immobilized native SAP, aggregated SAP and SAP-heparansulphate complexes induced no detectable complement activation.

SØrensen, Inge Juul; Nielsen, EH

1996-01-01

35

Native human serum amyloid P component is a single pentamer  

DEFF Research Database (Denmark)

Serum amyloid P component (SAP) and C-reactive protein (CRP) are members of the pentraxin protein family. SAP is the precursor protein to amyloid P component present in all forms of amyloidosis. The prevailing notion is that SAP in circulation has the form of a double pentameric molecule (decamer) whereas CRP is a single pentameric molecule. We have investigated by gel permeation chromatography the M(r) of SAP in freshly collected human serum and of SAP purified by carbohydrate affinity chromatography and anion exchange chromatography. SAP was monitored by quantitative immunoelectrophoresis and ELISA, and SAP peak fractions were analysed by use of SDS-PAGE, Western blotting, and electron microscopy. The results indicate that native SAP circulates as a single pentamer, a part of which forms complexes with C4b-binding protein. The properties of SAP changed during purification as indicated by rocket immunoelectrophoresis and electron microscopy. Thus, electron micrographs of purified SAP showed a predominance of decamers. However, the decamer form of SAP reversed to single pentamers when purified SAP was incorporated into SAP-depleted serum.

SØrensen, Inge Juul; Andersen, Ove

1995-01-01

36

Inhibition of TTR aggregation-induced cell death : a new role for serum amyloid P component  

OpenAIRE

BACKGROUND: Serum amyloid P component (SAP) is a glycoprotein that is universally found associated with different types of amyloid deposits. It has been suggested that it stabilizes amyloid fibrils and therefore protects them from proteolytic degradation. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we show that SAP binds not only to mature amyloid fibrils but also to early aggregates of amyloidogenic mutants of the plasma protein transthyretin (TTR). It does not inhibit fibril formation of...

Andersson, Karin; Pokrzywa, M.; Dacklin, Ingrid; Lundgren, Erik

2013-01-01

37

Specific localization and imaging of amyloid deposits in vivo using 123I-labeled serum amyloid P component  

International Nuclear Information System (INIS)

Highly specific, high-resolution scintigraphic images of amyloid-laden organs in mice with experimentally induced amyloid A protein (AA) amyloidosis were obtained after intravenous injection of 123I-labeled serum amyloid P component (SAP). Interestingly, a much higher proportion (up to 40%) of the injected dose of heterologous human SAP localized to amyloid and was retained there than was the case with isologous mouse SAP, indicating that human SAP binds more avidly to mouse AA fibrils than does mouse SAP. Specificity of SAP localization was established by the failure of the related proteins, human C-reactive protein and Limulus C-reactive protein, to deposit significantly in amyloid and by the absence of human SAP deposition in nonamyloidotic organs. However, only partial correlations were observed between the quantity of SAP localized and two independent estimates, histology and RIA for AA of the amount of amyloid in particular organs. It is not clear which of the three methods used reflects better the extent or clinical significance of the amyloid deposits but in vivo localization of radiolabeled SAP, detectable and quantifiable by gamma camera imaging, is apparently extremely sensitive. These findings establish the use of labeled SAP as a noninvasive in vivo diagnostic probe in experimental amyloidosis, potentially capable of revealing the natural history of the condition, and suggest that it may also be applicable generally as a specific targeting agenble generally as a specific targeting agent for diagnostic and even therapeutic purposes in clinical amyloidosis

38

The presence of a novel protein in calf serum that recognizes beta amyloid in the formalin-fixed section.  

OpenAIRE

Here we report on a monoclonal antibody, H6-33, that labels various beta-amyloid plaques, including diffuse plaques in the formalin-fixed, paraffin-embedded section from the brain affected with Alzheimer's disease (AD), without formic acid pretreatment. H6-33 also labels some neurofibrillary tangles and all kuru plaques in Gerstmann-Sträussler-Scheinker disease. In sharp contrast, H6-33 did not stain beta amyloid in the leptomeningeal vessel. For specific staining, H6-33 required the presenc...

Kanemaru, K.; Hasegawa, M.; Shimada, H.; Ihara, Y.

1990-01-01

39

Treatment Strategies Targeting Amyloid ?-Protein  

Science.gov (United States)

With the advent of the key discovery in the mid-1980s that the amyloid ?-protein (A?) is the core constituent of the amyloid plaque pathology found in Alzheimer disease (AD), an intensive effort has been underway to attempt to mitigate its role in the hope of treating the disease. This effort fully matured when it was clarified that the A? is a normal product of cleavage of the amyloid precursor protein, and well-defined proteases for this process were identified. Further therapeutic options have been developed around the concept of anti-A? aggregation inhibitors and the surprising finding that immunization with A? itself leads to reduction of pathology in animal models of the disease. Here we review the progress in this field toward the goal of targeting A? for treatment and prevention of AD and identify some of the major challenges for the future of this area of medicine. PMID:22951439

Schenk, Dale; Basi, Guriqbal S.; Pangalos, Menelas N.

2012-01-01

40

An in vitro study on neuroprotective effects of serum containing Gengnianchun decoction and its main monomers against amyloid beta protein-induced cellular toxicity  

Directory of Open Access Journals (Sweden)

Full Text Available Obiective: To observe the effects of serum containing Gengnianchun (GNC decoction, a compound traditional Chinese herbal medicine, and its monomers (paeoniflorin, berberine, timosaponin A-? and icariin on neurotoxicity in PC12 cells induced by amyloid beta-protein (A?.?Methods: Injury of PC12 cells was induced by in incubating with A?25-35 in vitro.? Ovariectomized rats were intragastrically administered with GNC decoction twice daily for 5 days and then sera were obtained. Different concentrations of serum containing GNC decoction and its main monomers including paeoniflorin, berberine, timosaponin and icariine and the monomer mixtures were cultured with PC12 cells to determine the best concentration of the drugs by methyl thiazolyl tetrazolium (MTT method. The effective concentration of A?25-35 was detemined by culturing PC12 cells with different concentrations of A?25-35. Then, the activity of PC12 cells with A?25-35-induced injury was observed with MTT method. Cellular morphological change was observed by phase contrast microscopy. Flow cytometry and fluorescence microscopy were employed to observe the A?25-35-induced early apoptosis of PC12 cells.?Results: After A?25-35 induction, the PC12 cells were fewer in number, less viable with shrinked cel1 body, many fragments, adhered less and nuclei shrinked. The cell proliferation was inhibited by A?25-35 concentration- and time?dependently. A?25-35 at concentration of 20 ?mol/ L was selected to construct the Alzheimer's disease model ?in vitro.? The sera containing GNC decoction could reinforce PC12 cell activity, and concentration at 20% was better than other concentrations after 24-, 48- and 72-hour culture. The 20% serum containing GNC decoction, 0.1 ?mol/L berberin and monomer mixture 3 including 1 mg/mL paeoniflorin, 1 ?mol/L berberine, 1 ?mol/L timosaponin and 1 ng/mL icariine could antagonize neurotoxicity induced by A?25-35. Moreover, they could inhibit A?25-35-induced early apoptosis of PC12 cells, with the effect of 20% serum containing GNC decoction better than 0.1 ?mol/L berberine and monomer mixture 3.Conclusion: Serum containing GNC decoction at 20% concentration has the potential neuroprotective effect on A?-induced cellular impairment. The serum containing GNC decoction was found to be stronger in action than the main monomers.

Wen-jun WANG

2010-01-01

41

Protection of human podocytes from shiga toxin 2-induced phosphorylation of mitogen-activated protein kinases and apoptosis by human serum amyloid P component.  

Science.gov (United States)

Hemolytic uremic syndrome (HUS) is mainly induced by Shiga toxin 2 (Stx2)-producing Escherichia coli. Proteinuria can occur in the early phase of the disease, and its persistence determines the renal prognosis. Stx2 may injure podocytes and induce proteinuria. Human serum amyloid P component (SAP), a member of the pentraxin family, has been shown to protect against Stx2-induced lethality in mice in vivo, presumably by specific binding to the toxin. We therefore tested the hypothesis that SAP can protect against Stx2-induced injury of human podocytes. To elucidate the mechanisms underlying podocyte injury in HUS-associated proteinuria, we assessed Stx2-induced activation of mitogen-activated protein kinases (MAPKs) and apoptosis in immortalized human podocytes and evaluated the impact of SAP on Stx2-induced damage. Human podocytes express Stx2-binding globotriaosylceramide 3. Stx2 applied to cultured podocytes was internalized and then activated p38? MAPK and c-Jun N-terminal kinase (JNK), important signaling steps in cell differentiation and apoptosis. Stx2 also activated caspase 3, resulting in an increased level of apoptosis. Coincubation of podocytes with SAP and Stx2 mitigated the effects of Stx2 and induced upregulation of antiapoptotic Bcl2. These data suggest that podocytes are a target of Stx2 and that SAP protects podocytes against Stx2-induced injury. SAP may therefore be a useful therapeutic option. PMID:24566618

Dettmar, Anne K; Binder, Elisabeth; Greiner, Friederike R; Liebau, Max C; Kurschat, Christine E; Jungraithmayr, Therese C; Saleem, Moin A; Schmitt, Claus-Peter; Feifel, Elisabeth; Orth-Höller, Dorothea; Kemper, Markus J; Pepys, Mark; Würzner, Reinhard; Oh, Jun

2014-05-01

42

Serum Amyloid A Truncations in Type 2 Diabetes Mellitus  

Science.gov (United States)

Serum Amyloid A (SAA) is an acute phase protein complex consisting of several abundant isoforms. The N- terminus of SAA is critical to its function in amyloid formation. SAA is frequently truncated, either missing an arginine or an arginine-serine dipeptide, resulting in isoforms that may influence the capacity to form amyloid. However, the relative abundance of truncated SAA in diabetes and chronic kidney disease is not known. Methods Using mass spectrometric immunoassay, the abundance of SAA truncations relative to the native variants was examined in plasma of 91 participants with type 2 diabetes and chronic kidney disease and 69 participants without diabetes. Results The ratio of SAA 1.1 (missing N-terminal arginine) to native SAA 1.1 was lower in diabetics compared to non-diabetics (p = 0.004), and in males compared to females (p<0.001). This ratio was negatively correlated with glycated hemoglobin (r = ?0.32, p<0.001) and triglyceride concentrations (r = ?0.37, p<0.001), and positively correlated with HDL cholesterol concentrations (r = 0.32, p<0.001). Conclusion The relative abundance of the N-terminal arginine truncation of SAA1.1 is significantly decreased in diabetes and negatively correlates with measures of glycemic and lipid control. PMID:25607823

Yassine, Hussein N.; Trenchevska, Olgica; He, Huijuan; Borges, Chad R.; Nedelkov, Dobrin; Mack, Wendy; Kono, Naoko; Koska, Juraj; Reaven, Peter D.; Nelson, Randall W.

2015-01-01

43

Prefibrillar oligomeric Transthyretin mutants - amyloid conformation, toxicity and association with Serum amyloid P component  

OpenAIRE

Amyloidoses represent a heterogeneous group of diseases characterized by abnormal protein metabolism leading to extracellular deposition of fibrillar, proteinaceous amyloid in various tissues and organs of the body. To date more than 20 different proteins have been linked to diseases with amyloid depositions, of which Alzheimer’s disease and the prion-associated diseases are the most well known. Despite the origin of protein in the amyloid, the fibrils share some common biochemical and biop...

Andersson, Karin

2005-01-01

44

Protection of Human Podocytes from Shiga Toxin 2-Induced Phosphorylation of Mitogen-Activated Protein Kinases and Apoptosis by Human Serum Amyloid P Component  

OpenAIRE

Hemolytic uremic syndrome (HUS) is mainly induced by Shiga toxin 2 (Stx2)-producing Escherichia coli. Proteinuria can occur in the early phase of the disease, and its persistence determines the renal prognosis. Stx2 may injure podocytes and induce proteinuria. Human serum amyloid P component (SAP), a member of the pentraxin family, has been shown to protect against Stx2-induced lethality in mice in vivo, presumably by specific binding to the toxin. We therefore tested the hypothesis that SAP ...

Dettmar, Anne K.; Binder, Elisabeth; Greiner, Friederike R.; Liebau, Max C.; Kurschat, Christine E.; Jungraithmayr, Therese C.; Saleem, Moin A.; Schmitt, Claus-peter; Feifel, Elisabeth; Orth-ho?ller, Dorothea; Kemper, Markus J.; Pepys, Mark; Wu?rzner, Reinhard; Oh, Jun

2014-01-01

45

Serum amyloid A induces interleukin-1? secretion from keratinocytes via the NACHT, LRR and PYD domains-containing protein 3 inflammasome.  

Science.gov (United States)

Interleukin (IL)-1? is now emerging as a critical cytokine in the pathogenesis of T helper type 17 (Th17)-mediated skin diseases, including psoriasis. Psoriatic keratinocytes are a major source of IL-1?; however, the mechanisms triggering IL-1? processing remain unknown. Recently, an acute-phase protein serum amyloid A (SAA) has been identified as a danger signal that triggers inflammasome activation and IL-1? secretion. In this study, we detected increased SAA mRNA and protein expression in psoriatic epidermis. In cultured keratinocytes, SAA up-regulated the expression of pro-IL-1? and secretion of mature IL-1?. On the transcriptional level, blocking Toll-like receptor-2 (TLR-2), TLR-4 or nuclear factor kappa B (NF-?B) attenuated SAA-induced expression of IL-1? mRNA. SAA up-regulated caspase-1 and NACHT, LRR and PYD domains-containing protein 3 (NLRP3) expression in keratinocytes. Inhibiting caspase-1 activity and silencing NLRP3 decreased IL-1? secretion, confirming NLRP3 as the SAA-responsive inflammasome on the post-transcriptional level. The mechanism of SAA-triggered NLRP3 activation and subsequent IL-1? secretion was found to involve the generation of reactive oxygen species. Finally, the expression of SAA by keratinocytes was up-regulated by IL-17A. Taken together, our results indicate that keratinocyte-derived SAA triggers a key inflammatory mediator, IL-1?, via NLRP3 inflammasome activation, providing new potential targets for the treatment of this chronic skin disease. PMID:25231464

Yu, N; Liu, S; Yi, X; Zhang, S; Ding, Y

2015-02-01

46

Amyloid Aggregation and Membrane Disruption by Amyloid Proteins  

Science.gov (United States)

Amyloidogenesis has been the focus of intense basic and clinical research, as an increasing number of amyloidogenic proteins have been linked to common and incurable degenerative diseases including Alzheimer's, type II diabetes, and Parkinson's. Recent studies suggest that the cell toxicity is mainly due to intermediates generated during the assembly process of amyloid fibers, which have been proposed to attack cells in a variety of ways. Disruption of cell membranes is believed to be one of the key components of amyloid toxicity. However, the mechanism by which this occurs is not fully understood. Our research in this area is focused on the investigation of the early events in the aggregation and membrane disruption of amyloid proteins, Islet amyloid polypeptide protein (IAPP, also known as amylin) and amyloid-beta peptide, on the molecular level. Structural insights into the mechanisms of membrane disruption by these amyloid proteins and the role of membrane components on the membrane disruption will be presented.[4pt] References:[0pt] [1] Sciacca et al., Biophys. J. 2012, 103, 702-10.[0pt] [2] Sciacca et al., Biochemistry. 2012, 51, 7676-84[0pt] [3] Brender et al., Acc. Chem. Res. 2012, 45, 454-62.[0pt] [4] Nanga et al., Biochim. Biophys. Acta 2011, 1808, 2337-42.[0pt] [5] Brender et al., Biophys J. 2011, 100, 685-92.

Ramamoorthy, Ayyalusamy

2013-03-01

47

A pertussis toxin sensitive G-protein-independent pathway is involved in serum amyloid A-induced formyl peptide receptor 2-mediated CCL2 production  

OpenAIRE

Serum amyloid A (SAA) induced CCL2 production via a pertussis toxin (PTX)-insensitive pathway in human umbilical vein endothelial cells (HUVECs). SAA induced the activation of three MAPKs (ERK, p38 MAPK, and JNK), which were completely inhibited by knock-down of formyl peptide receptor 2 (FPR2). Inhibition of p38 MAPK and JNK by their specific inhibitors (SB203580 and SP600125), or inhibition by a dominant negative mutant of p38 MAPK dramatically decreased SAA-induced CCL2 production. Inactiv...

Lee, Ha Young; Kim, Sang Doo; Shim, Jae Woong; Kim, Hak Jung; Yun, Jeanho; Baek, Suk-hwan; Kim, Koanhoi; Bae, Yoe-sik

2010-01-01

48

Does serum degrade amyloid fibrils? Failure to confirm enzymatic degradation of amyloid A fibrils as the basis of the so-called ''amyloid degrading activity'' of serum  

International Nuclear Information System (INIS)

Several reports from different laboratories on the capacity of serum to degrade amyloid A fibrils have been published since the 1979 Symposium on Amyloidosis. These are based on the observation that whole serum or isolated serum albumin causes increased translucency in turbid agarose gels containing AA fibrils. We report here a critical study of the phenomenon itself both in the gel and in solution. The clearing capacity of serum samples correlated well with albumin concentration and as previously shown by others was manifested by isolated albumin preparations. Clearing did not involve enzymatic degradation of amyloid fibrils. Serum albumin is known to improve the optical clarity of agarose gels. We propose that optical clearing without degradation is the basis of the so-called amyloid degrading activity of human serum. This activity does not seem to be of in vivo importance in amyloidogenesis

49

Serum amyloid A isoforms in serum and synovial fluid from spontaneously diseased dogs with joint diseases or other conditions  

DEFF Research Database (Denmark)

Serum amyloid A (SAA) is a major acute phase protein in dogs. However, knowledge of qualitative properties of canine SAA and extent of its synthesis in extrahepatic tissues is limited. The aim of the study was to investigate expression of different SAA isoforms in serum and synovial fluid in samples obtained from dogs (n = 16) suffering from different inflammatory or non-inflammatory conditions, which were either related or unrelated to joints. Expression of SAA isoforms was visualized by denaturing isoelectric focusing and Western blotting. Serum amyloid A was present in serum from all dogs with systemic inflammatory activity, and up to four major isoforms with apparent isoelectric points between 6.1 and 7.9 were identified. In synovial fluid from inflamed joints one or more highly alkaline SAA isoforms (with apparent isoelectric points above 9.3) were identified, with data suggesting local production of these isoforms in the canine inflamed joint.

Kjelgaard-Hansen, Mads Jens; Christensen, Michelle B.

2007-01-01

50

A serum amyloid P-binding hydrogel speeds healing of partial thickness wounds in pigs  

OpenAIRE

During wound healing, some circulating monocytes enter the wound, differentiate into fibroblast-like cells called fibrocytes, and appear to then further differentiate into myofibroblasts, cells that play a key role in collagen deposition, cytokine release, and wound contraction. The differentiation of monocytes into fibrocytes is inhibited by the serum protein serum amyloid P (SAP). Depleting SAP at a wound site thus might speed wound healing. SAP binds to some types of agarose in the presenc...

Gomer, Richard H.; Pilling, Darrell; Kauvar, Lawrence M.; Ellsworth, Stote; Ronkainen, Sanna D.; Roife, David; Davis, Stephen C.

2009-01-01

51

Relationship between haptoglobin and serum amyloid A in milk and milk quality  

OpenAIRE

The objective of this study was to evaluate relationships between the presence in milk of the major bovine acute phase proteins, haptoglobin (Hp) and serum amyloid A (SAA), and milk quality parameters. Composite milk samples were collected from 89 clinically healthy dairy cows and analysed for Hp and SAA, total protein, casein, and whey protein levels, casein number, proteolysis, total fat and lactose levels, and somatic cell count (SCC). Milk samples with detectable levels of Hp showed lower...

A?kerstedt, Maria; Persson Waller, Karin; Bach Larsen, Lotte; Forsba?ck, Linda; Sternesjo?, A?se

2008-01-01

52

The human serum amyloid A protein (SAA) superfamily gene cluster: Mapping to chromosome 11p15. 1 by physical and genetic linkage analysis  

Energy Technology Data Exchange (ETDEWEB)

The human serum amyloid A protein (SAA) family comprises a number of small, hepatically produced, differentially expressed apolipoproteins encoded by genes localized on the short arm of chromosome 11. SAA1 and SAA2 are highly related genes that together encode the acute-phase SAAs; SAA3 is a pseudogene; and SAA4 is a low-level constitutively expressed gene encoding constitutive SAA. The authors have used a combination of physical and genetic mapping techniques to provide evidence that the SAA gene superfamily comprises a cluster of closely linked genes localized to 11p15.1. Pulsed-field gel electrophoresis placed SAA 1 to within 350 kb of the previously linked SAA2 and SAA4 genes. SAA locus-specific polymerase chain reaction amplification from a panel of somatic cell hybrids carrying defined regions of chromosome 11p mapped all four loci to 11p15.1pter. Fluorescence in situ hybridization analysis using a cosmid probe carrying the SAA2 and SAA4 genes refined the localization of these genes (and SAA1) to 11p15.1. To order SAA3 on the genetic map, a highly polymorphic (CA)[sub n] dinucleotide repeat within SAA3 was typed through the CEPH reference families. In accordance with the physical localization of SAAs 1, 2, and 4, SAA3 maps to the 11p15.1 region proximal to the parathyroid hormone (PTH) locus ([theta] = 0.02; lod = 12.020) and distal to D11S455 ([theta] = 0.058, lod = 8.274). To provide further evidence of an SAA superfamily gene cluster, an NcoI restriction fragment length polymorphism in the SAA2 gene was also typed through the CEPH reference panel. Two-point lod score analysis gave [theta] = 0.001, with lod = 10.82 between SAA3 and SAA2, thereby firmly confirming close linkage between all known SAA superfamily members on chromosome 11p15.1. 41 refs., 4 figs., 1 tab.

Sellar, G.C.; Jordan, S.A.; Whitehead, A.S. (Univ. of Dublin (Ireland)); Bickmore, W.A.; Fantes, J.A.; Van Heyningen, V. (Western General Hospital, Edinburgh (United Kingdom))

1994-01-15

53

Protein fibrils in nature can enhance amyloid protein A amyloidosis in mice: Cross-seeding as a disease mechanism  

OpenAIRE

Secondary, or amyloid protein A (AA), amyloidosis is a complication of chronic inflammatory diseases, both infectious and noninfectious. AA constitutes the insoluble fibrils, which are deposited in different organs, and is a major N-terminal part of the acute phase protein serum AA. It is not known why only some patients with chronic inflammation develop AA amyloidosis. Nucleation is a widely accepted mechanism in amyloidogenesis. Preformed amyloid-like fibrils act as nuclei in amyloid fibril...

Lundmark, Katarzyna; Westermark, Gunilla T.; Olse?n, Arne; Westermark, Per

2005-01-01

54

Transthyretin sequesters amyloid beta protein and prevents amyloid formation  

DEFF Research Database (Denmark)

The cardinal pathological features of Alzheimer disease are depositions of aggregated amyloid beta protein (A beta) in the brain and cerebrovasculature. However, the A beta is found in a soluble form in cerebrospinal fluid in healthy individuals and patients with Alzheimer disease. We postulate that sequestration of A beta precludes amyloid formation. Failure to sequester A beta in Alzheimer disease may result in amyloidosis. When we added A beta to cerebrospinal fluid of patients and controls it was rapidly sequestered into stable complexes with transthyretin. Complexes with apolipoprotein E, which has been shown to bind A beta in vitro, were not observed in cerebrospinal fluid. Additional in vitro studies showed that both purified transthyretin and apolipoprotein E prevent amyloid formation.

Schwarzman, A L; Gregori, L

1994-01-01

55

Monoclonal hybridoma antibodies to human amyloid related protein SAA.  

Science.gov (United States)

Problems concerning isolation and characterization of the amyloid related serum protein SAA in a pure form prompted us to make monoclonal antibodies to the protein. Protein SAA isolated by gel filtration under dissociating conditions was used for immunization of BALB/c mice, and spleen cells from a mouse producing high titred antiserum to SAA were fused with cells from the mouse plasmacytoma line P3U1. Antibody specificity to various preparations of protein SAA was tested using an indirect enzyme-linked immunosorbent assay. Monoclonal antibodies with specificity for SAA were obtained in addition to antibodies which reacted with both SAA and the related amyloid protein AA. Antibodies specific for one of the apoC proteins of the lipoprotein fraction were also produced showing that the SAA preparation used for immunization was contaminated with apoC proteins. PMID:7151332

Marhaug, G; Gaudernack, G; Bogen, B; Husby, G

1982-01-01

56

Antibody-Array Interaction Mapping, a New Method to Detect Protein Complexes Applied to the Discovery and Study of Serum Amyloid P Interactions with Kininogen in Human Plasma*  

OpenAIRE

Protein-protein interactions are fundamentally important in biological processes, but the existing analytical tools have limited ability to sensitively and precisely measure the dynamic composition of protein complexes in biological samples. We report here the development of antibody-array interaction mapping (AAIM) to address that need. We used AAIM to probe interactions among a set of 48 proteins in serum and found several known interactions as well potentially novel interactions, including...

Bergsma, Derek; Chen, Songming; Buchweitz, John; Gerszten, Robert; Haab, Brian B.

2009-01-01

57

Ligand-binding sites in human serum amyloid P component  

DEFF Research Database (Denmark)

Amyloid P component (AP) is a naturally occurring glycoprotein that is found in serum and basement membranes, AP is also a component of all types of amyloid, including that found in individuals who suffer from Alzheimer's disease and Down's syndrome. Because AP has been found to bind strongly and specifically to certain glycosaminoglycans that are components of amyloid deposits, AP may play an important role in the maintenance of amyloid. In the present work, we isolated and identified two proteolytic fragments of AP that are responsible for its heparin-binding activity. Neither fragment corresponds to published heparin-binding sequences. The structural requirements for activity of the peptides (amino acid residues 27-38 and 192-203 of AP) were examined by means of solid-phase inhibition assays with synthetic peptides, AP-(192-203)-peptide inhibits the Ca2+-dependent binding of AP to heparin with an IC50 of 25 mu M, while the IC50 of AP-(27-38)-peptide and AP-(33-38)-peptide are 10 mu M and 2 mu M, respectively, The understanding of the structure and function of active AP peptides will be useful for development of amyloid-targeted diagnostics and therapeutics.

Heegaard, N.H.H.; Heegaard, Peter M. H.

1996-01-01

58

Multiphoton absorption in amyloid protein fibres  

Science.gov (United States)

Fibrillization of peptides leads to the formation of amyloid fibres, which, when in large aggregates, are responsible for diseases such as Alzheimer's and Parkinson's. Here, we show that amyloids have strong nonlinear optical absorption, which is not present in native non-fibrillized protein. Z-scan and pump-probe experiments indicate that insulin and lysozyme ?-amyloids, as well as ?-synuclein fibres, exhibit either two-photon, three-photon or higher multiphoton absorption processes, depending on the wavelength of light. We propose that the enhanced multiphoton absorption is due to a cooperative mechanism involving through-space dipolar coupling between excited states of aromatic amino acids densely packed in the fibrous structures. This finding will provide the opportunity to develop nonlinear optical techniques to detect and study amyloid structures and also suggests that new protein-based materials with sizable multiphoton absorption could be designed for specific applications in nanotechnology, photonics and optoelectronics.

Hanczyc, Piotr; Samoc, Marek; Norden, Bengt

2013-12-01

59

Protein chemistry: Catalytic amyloid fibrils  

Science.gov (United States)

Amyloid fibrils are formed from polypeptide chains assembled into an organized fibrillar structure. Now, it has been shown that such fibrillar structures can also bind metal ions and catalyse chemical reactions.

Aumüller, Tobias; Fändrich, Marcus

2014-04-01

60

Evaluation of systemic amyloidosis by scintigraphy with 123I-labeled serum amyloid P component  

International Nuclear Information System (INIS)

In systemic amyloidosis the distribution and progression of disease have been difficult to monitor, because they can be demonstrated only by biopsy. Serum amyloid P component (SAP) is a normal circulating plasma protein that is deposited on amyloid fibrils because of its specific binding affinity for them. We investigated whether labeled SAP could be used to locate amyloid deposits. Purified human SAP labeled with iodine-123 was given intravenously to 50 patients with biopsy-proved systemic amyloidosis--25 with the AL (primary) type and 25 with the AA (secondary) type--and to 26 control patients with disease and 10 healthy subjects. Whole-body images and regional views were obtained after 24 hours and read in a blinded fashion. In the patients with amyloidosis the 123I-SAP was localized rapidly and specifically in amyloid deposits. The scintigraphic images obtained were characteristic and appeared to identify the extent of amyloid deposition in all 50 patients. There was no uptake of the 123I-SAP by the control patients and the healthy subjects. In all patients with AA amyloidosis the spleen was affected, whereas the scans showed uptake in the heart, skin, carpal region, and bone marrow only in patients with the AL type. Positive images were seen in six patients in whom biopsies had been negative or unsuccessful; in all six, amyloid was subsequently found on biopsy or at autopsy. Progressive amyloid deposition was observed in 9 of 11 patients studied serially. Scintig9 of 11 patients studied serially. Scintigraphy after the injection of 123I-SAP can be used for diagnosing, locating, and monitoring the extent of systemic amyloidosis

61

Expression of serum amyloid a in equine wounds  

DEFF Research Database (Denmark)

OBJECTIVES Aberrant wound healing with formation of exuberant granulation tissue (EGT) occurs frequently in horses and may affect their athletic career and quality of life. The objective of the study was to determine mRNA expression levels of serum amyloid A (SAA) in normal and aberrant wound healing in horses. METHODS Experimental wounds were made in six horses on both metatarsi and on regio brachii. One limb was bandaged to provoke formation of EGT. Biopsies were collected on day 21 and were divided in three groups: body wounds (regio brachii), unbandaged limb wounds (normal healing), and bandaged limb wounds (aberrant healing with formation of EGT). All biopsies were examined for the relative mRNA expression level of SAA using qRT-PCR. Differences in SAA expression levels between the three groups were analyzed by Kruskal-Wallis test and Dunns test. RESULTS SAA mRNA level was significantly higher (P < 0.01) in limb wounds healing with EGT formation than in body and limb wounds with normal healing. In body wounds and limb wounds with normal healing SAA expression was very low, in EGT SAA expression levels varied from low to very high. CONCLUSIONS SAA is a major equine acute phase protein, which is produced in the liver and several extrahepatic tissues during inflammatory conditions. This study shows that cells in EGT derived from horses produce SAA. This may be related to the length of the inflammatory phase of the wound healing, which is short (approximately 3 days) in wounds with normal healing, but protracted in wounds developing EGT. Chronic inflammation might facilitate binding of SAA-containing high density lipoproteins (HDL) to extracellular vascular proteoglycans, which would favour retention and modification of HDL by the vascular matrix. Such changes could be the pathophysiological reason underlying endothelial cell dysfunction and subsequently hypoxia, which has been implicated in EGT formation.

SØrensen, Mette Aamand; Jacobsen, Stine

62

Immunoradiometric assay for human serum amyloid P component.  

Science.gov (United States)

Human serum amyloid P component (SAP) is of increasing interest for its possible pathogenic role in amyloidosis and Alzheimer's disease, and as a therapeutic target in these conditions. We have developed and validated a robust and reproducible immunoradiometric assay (IRMA) for human SAP in serum, plasma and cerebrospinal fluid, and characterized the notable stability of human SAP immunoreactivity during storage of undiluted serum at 4°C and 37°C as well as frozen at -30°C. SAP values were also stable after repeated freeze thawing of highly diluted serum samples. The 100 fold dynamic range of the assay, 0.5-50 ?g/L, encompassed all values seen in blood and cerebrospinal fluid, when tested at suitable dilutions, from both normal healthy individuals and patients, including subjects receiving the SAP-depleting drug, CPHPC. Furthermore by comparing the IRMA values in the presence and absence of calcium, the new assay revealed interference due to the binding of CPHPC by SAP, which was markedly enhanced in heparinized plasma. It is therefore essential that SAP assays in samples from patients on CPHPC be conducted in the absence of free calcium, in order to completely abrogate interference and determine the actual total SAP concentration. Estimates by the IRMA of SAP concentration in 49 serum samples from amyloidosis patients corresponded closely with those obtained by the established standard electro-immunoassay method and by a newly developed commercial ELISA kit (Hycult Biotechnology). PMID:21708157

Millar, David J; Hutchinson, Winston L; Pepys, Mark B

2011-08-31

63

The amyloid state of proteins in human diseases  

OpenAIRE

Amyloid fibers and oligomers are associated with a great variety of human diseases including Alzheimer’s disease and the prion conditions. Here we attempt to connect recent discoveries on the molecular properties of proteins in the amyloid state with observations about pathological tissues and disease states. We summarize studies of structure and nucleation of amyloid and relate these to observations on amyloid polymorphism, prion strains, co-aggregation of pathogenic proteins in tissues, a...

Eisenberg, David; Jucker, Mathias

2012-01-01

64

Imaging of experimental amyloidosis with 131I-labeled serum amyloid P component  

International Nuclear Information System (INIS)

131I-labeled human serum amyloid P component, which was injected into mice with experimentally induced systemic AA amyloidosis and into controls, became specifically localized and was retained in amyloidotic organs. In comparison, it was rapidly and completely eliminated from unaffected tissues and from control animals. Distinctive images of this amyloid-specific deposition of labeled serum amyloid P component were derived from whole body scanning, in vivo, of amyloidotic mice. These findings suggest that such imaging may have applications for the diagnosis and quantitation of amyloid deposits in humans

65

Serum concentrations of haptoglobin and serum amyloid A in water buffaloes (Bubalus bubalis with abomasal ulcer  

Directory of Open Access Journals (Sweden)

Full Text Available To evaluate the serum concentrations of haptoglobin (Hp and serum amyloid A (SAA in water buffaloes with abomasal ulcers, the abomasums of 100 randomly selected water buffaloes were examined after slaughter. Type I abomasal ulcers were found in 56 out of 100 buffaloes. Serum concentrations of Hp and SAA were measured. There was no significant difference between affected and non-affected buffaloes in the serum concentrations of Hp and SAA. The serum concentrations of Hp and SAA had no significant correlation with age and the serum SAA revealed no significant correlation with the number of abomasal ulcers. A significant correlation was found between the serum Hp and the number of abomasal ulcers (r =0.29, p = 0.04. There was no significant difference in the serum concentrations of Hp and SAA between buffaloes with different ulcer locations in the abomasums. Although more work on a larger number of animals is required in this area, it seems that the measurement of the serum Hp can be used to predict the abundance of type I abomasal ulcers.

Javad Tajik

2012-09-01

66

Serum concentrations of haptoglobin and serum amyloid A in water buffaloes (Bubalus bubalis) with abomasal ulcer  

Science.gov (United States)

To evaluate the serum concentrations of haptoglobin (Hp) and serum amyloid A (SAA) in water buffaloes with abomasal ulcers, the abomasums of 100 randomly selected water buffaloes were examined after slaughter. Type I abomasal ulcers were found in 56 out of 100 buffaloes. Serum concentrations of Hp and SAA were measured. There was no significant difference between affected and non-affected buffaloes in the serum concentrations of Hp and SAA. The serum concentrations of Hp and SAA had no significant correlation with age and the serum SAA revealed no significant correlation with the number of abomasal ulcers. A significant correlation was found between the serum Hp and the number of abomasal ulcers (r =0.29, p = 0.04). There was no significant difference in the serum concentrations of Hp and SAA between buffaloes with different ulcer locations in the abomasums. Although more work on a larger number of animals is required in this area, it seems that the measurement of the serum Hp can be used to predict the abundance of type I abomasal ulcers.

Tajik, Javad; Nazifi, Saeed; Heidari, Mahdi; Babazadeh, Marzieh

2012-01-01

67

A prospective study of the sensitivity, specificity and diagnostic performance of soluble intercellular adhesion molecule 1, highly sensitive C-reactive protein, soluble E-selectin and serum amyloid A in the diagnosis of neonatal infection  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Diagnosis of neonatal infection is difficult, because of it's non-specific clinical presentation and the lack of reliable diagnostic tests. The purpose of this study was to examine the potential diagnostic value of serum soluble intercellular adhesion molecule-1 (sICAM-1, soluble E-selectin (sE-selectin, highly sensitive C-reactive protein (hsCRP and serum amyloid A (SAA measurements, both individually and in combination in the setting of a neonatal intensive care unit. Methods 219 consecutive serum samples were taken from 149 infants undergoing sepsis work up in a neonatal intensive care unit. Clinical diagnosis was established in a prospective manner, blind to the results of the study measurements. Infants were classified by an experienced paediatrician as infected or not-infected, one week after presentation. Classification was based on clinical presentation, routine laboratory and radiological investigations and response to therapy. The infected group were sub-classified as (a culture positive infection or (b culture negative infection. sICAM-1, sE-selectin, hsCRP and SAA levels were determined from stored serum samples after diagnosis was established. Further sub-group analysis of results was undertaken according to early or late onset of infection and preterm or term status. Statistical analysis utilised Mann Whitney U test and ROC curve analysis. Results There were significantly increased serum levels of sICAM-1, hsCRP, E selectin (p Conclusions All four study measurements demonstrated some diagnostic value for neonatal infection however sICAM-1, hsCRP and sE-selectin demonstrated the highest NPV individually. The optimum diagnostic cut off level for hsCRP measurement in this study was much lower than currently used in routine clinical practice. Use of a combination of measurements enhanced diagnostic performance, demonstrating sensitivity of 90.3% and NPV of 91.3%. This study suggests there may be value in use of several of these markers, individually and in combination to assist in excluding neonatal infection. Further work is needed to confirm a specific role in the exclusion of early onset infection.

Gallimore J Ruth

2010-04-01

68

Iodine-123-labelled serum amyloid P component scintigraphy in amyloidosis  

International Nuclear Information System (INIS)

This study describes the results of scintigraphy with iodine-123-labelled serum amyloid P component (SAP) as a means of establishing the distribution of organ involvement in amyloidosis. The significance of 123I-SAP scans obtained in 15 patients with biopsy-proven AA or AL amyloidosis is discussed. Biopsy-proven amyloidosis was typically confirmed by scintigraphy, though such confirmation was not obtained in the kidneys in six patients with histological proof of extensive renal amyloid deposition. This lack of uptake may have been due to the accumulation of a major part of the 123I-SAP in the spleen and/or liver. Twenty-four hour whole-body retention of 123I-SAP was higher in patients with amyloidosis than in controls. Twenty-four hour tracer accumulation of the radioactivity in the extravascular compartment was notably greater in patients than in controls and appeared to be a good diagnostic criterion. We conclude that 123I-SAP scintigraphy may be helpful for the evaluation of organ involvement not only in patients with biopsy-proven amyloidosis but also when a biopsy cannot be performed or when a strong suspicion of amyloidosis exists in spite of repeated negative biopsises. (orig.)

69

Amyloid ?-sheet mimics that antagonize protein aggregation and reduce amyloid toxicity  

Science.gov (United States)

The amyloid protein aggregation associated with diseases such as Alzheimer's, Parkinson's and type II diabetes (among many others) features a bewildering variety of ?-sheet-rich structures in transition from native proteins to ordered oligomers and fibres. The variation in the amino-acid sequences of the ?-structures presents a challenge to developing a model system of ?-sheets for the study of various amyloid aggregates. Here, we introduce a family of robust ?-sheet macrocycles that can serve as a platform to display a variety of heptapeptide sequences from different amyloid proteins. We have tailored these amyloid ?-sheet mimics (ABSMs) to antagonize the aggregation of various amyloid proteins, thereby reducing the toxicity of amyloid aggregates. We describe the structures and inhibitory properties of ABSMs containing amyloidogenic peptides from the amyloid-? peptide associated with Alzheimer's disease, ?2-microglobulin associated with dialysis-related amyloidosis, ?-synuclein associated with Parkinson's disease, islet amyloid polypeptide associated with type II diabetes, human and yeast prion proteins, and Tau, which forms neurofibrillary tangles.

Cheng, Pin-Nan; Liu, Cong; Zhao, Minglei; Eisenberg, David; Nowick, James S.

2012-11-01

70

Validación analítica de técnicas comerciales para la determinación de haptoglobina, proteína C reactiva y amiloide A sérico en caninos Analytical validation of commercial assays for the determination of haptoglobin, C-reactive protein and serum amyloid A in dogs  

Directory of Open Access Journals (Sweden)

Full Text Available Los métodos analíticos deben ser validados antes de emplearlos de forma rutinaria en un laboratorio. El objetivo de este trabajo fue validar tres métodos analíticos comerciales usados en nuestro laboratorio para la determinación de haptoglobina (Hp, proteína C reactiva (CRP y amiloide A sérico (SAA en muestras de la especie canina con concentraciones bajas y altas de proteínas de fase aguda (PFAs. Los parámetros que se evaluaron para la validación fueron: (1 Precisión, determinada mediante el cálculo de los coeficientes de variación (CVs intra e interdeterminación. (2 Exactitud, evaluada indirectamente comprobando la linealidad bajo dilución. (3 Límite de detección, determinado como la mínima concentración que puede distinguirse de una muestra de valor 0. Todos los CVs intradeterminación fueron All laboratory tests must be validated before being introduced for patient testing. The objective of this work was to perform the analytical validation of three commercial assays that are being used at our laboratory for the determination of haptoglobin (Hp, C reactive protein (CRP and serum amyloid A (SAA in canine samples with low and high concentrations of these acute phase proteins (APPs. The parameters evaluated for the validation of the methods were: (1 Precision, assessed by determination of the within and between-run coefficients of variation (CVs. (2 Inaccuracy, evaluated indirectly by investigating linearity under dilution. (3 Limit of detection, determined as the lowest concentration of the APPs which could be distinguished from a zero sample. All within-run CVs were lower than 10%, however between-run CVs were lower than 10% only for Hp. Dilution of a serum sample with high concentrations of the different APPs resulted in a linear regression equation with correlation coefficient R²0.98 in all cases; so all methods showed a good accuracy. The detection limit of each assay was 0.02 g/L for Hp, 0.15 mg/L for CRP and 0.79 mg/L for SAA. Additionally they differentiate animals with inflammatory or infectious diseases from healthy subjects. Overall results of validation showed that the assays tested can be suitable for the routine measurement of APPs in canine samples, although it would be desirable to reduce the between run imprecision found for CRP and SAA assays.

S. Martínez-Subiela

2005-01-01

71

Beta-amyloid precursor protein cleavage by a membrane-bound protease.  

OpenAIRE

The principal component of amyloid plaques in Alzheimer disease is beta-amyloid protein, an approximately 4-kDa peptide derived from amyloid precursor proteins. Previous studies have established that amyloid precursor proteins are secreted after proteolytic cleavage within the beta-amyloid peptide. The present investigation documents that, in cultured cells, amyloid precursor protein is cleaved on the plasma membrane by a membrane-bound endoprotease and that the specificity of peptide bond hy...

Sisodia, S. S.

1992-01-01

72

Statistical Mechanical Treatments of Protein Amyloid Formation  

CERN Document Server

Protein aggregation is an important field of investigation because it is closely related to the problem of neurodegenerative diseases, to the development of biomaterials, and to the growth of cellular structures such as cyto-skeleton. Self-aggregation of protein amyloids, for example, is a complicated process involving many species and levels of structures. This complexity, however, can be dealt with using statistical mechanical tools, such as free energies, partition functions, and transfer matrices. In this article, we review general strategies for studying protein aggregation using statistical mechanical approaches and show that canonical and grand canonical ensembles can be used in such approaches. The grand canonical approach is particularly convenient since competing pathways of assembly and dis-assembly can be considered simultaneously. Another advantage of using statistical mechanics is that numerically exact solutions can be obtained for all of the thermodynamic properties of fibrils, such as the amo...

Schreck, John S

2013-01-01

73

Soluble aggregates of the amyloid-? peptide are trapped by serum albumin to enhance amyloid-? activation of endothelial cells  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Self-assembly of the amyloid-? peptide (A? has been implicated in the pathogenesis of Alzheimer's disease (AD. As a result, synthetic molecules capable of inhibiting A? self-assembly could serve as therapeutic agents and endogenous molecules that modulate A? self-assembly may influence disease progression. However, increasing evidence implicating a principal pathogenic role for small soluble A? aggregates warns that inhibition at intermediate stages of A? self-assembly may prove detrimental. Here, we explore the inhibition of A?1–40 self-assembly by serum albumin, the most abundant plasma protein, and the influence of this inhibition on A?1–40 activation of endothelial cells for monocyte adhesion. Results It is demonstrated that serum albumin is capable of inhibiting in a dose-dependent manner both the formation of A?1–40 aggregates from monomeric peptide and the ongoing growth of A?1–40 fibrils. Inhibition of fibrillar A?1–40 aggregate growth is observed at substoichiometric concentrations, suggesting that serum albumin recognizes aggregated forms of the peptide to prevent monomer addition. Inhibition of A?1–40 monomer aggregation is observed down to stoichiometric ratios with partial inhibition leading to an increase in the population of small soluble aggregates. Such partial inhibition of A?1–40 aggregation leads to an increase in the ability of resulting aggregates to activate endothelial cells for adhesion of monocytes. In contrast, A?1–40 activation of endothelial cells for monocyte adhesion is reduced when more complete inhibition is observed. Conclusion These results demonstrate that inhibitors of A? self-assembly have the potential to trap small soluble aggregates resulting in an elevation rather than a reduction of cellular responses. These findings provide further support that small soluble aggregates possess high levels of physiological activity and underscore the importance of resolving the effect of A? aggregation inhibitors on aggregate size.

Gonzalez-Velasquez Francisco J

2009-04-01

74

Formation of soluble amyloid oligomers and amyloid fibrils by the multifunctional protein vitronectin  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The multifunctional protein vitronectin is present within the deposits associated with Alzheimer disease (AD, age-related macular degeneration (AMD, atherosclerosis, systemic amyloidoses, and glomerulonephritis. The extent to which vitronectin contributes to amyloid formation within these plaques, which contain misfolded, amyloidogenic proteins, and the role of vitronectin in the pathophysiology of the aforementioned diseases is currently unknown. The investigation of vitronectin aggregation is significant since the formation of oligomeric and fibrillar structures are common features of amyloid proteins. Results We observed vitronectin immunoreactivity in senile plaques of AD brain, which exhibited overlap with the amyloid fibril-specific OC antibody, suggesting that vitronectin is deposited at sites of amyloid formation. Of particular interest is the growing body of evidence indicating that soluble nonfibrillar oligomers may be responsible for the development and progression of amyloid diseases. In this study we demonstrate that both plasma-purified and recombinant human vitronectin readily form spherical oligomers and typical amyloid fibrils. Vitronectin oligomers are toxic to cultured neuroblastoma and retinal pigment epithelium (RPE cells, possibly via a membrane-dependent mechanism, as they cause leakage of synthetic vesicles. Oligomer toxicity was attenuated in RPE cells by the anti-oligomer A11 antibody. Vitronectin fibrils contain a C-terminal protease-resistant fragment, which may approximate the core region of residues essential to amyloid formation. Conclusion These data reveal the propensity of vitronectin to behave as an amyloid protein and put forth the possibilities that accumulation of misfolded vitronectin may contribute to aggregate formation seen in age-related amyloid diseases.

Langen Ralf

2008-10-01

75

Statistical Mechanical Treatments of Protein Amyloid Formation  

Directory of Open Access Journals (Sweden)

Full Text Available Protein aggregation is an important field of investigation because it is closely related to the problem of neurodegenerative diseases, to the development of biomaterials, and to the growth of cellular structures such as cyto-skeleton. Self-aggregation of protein amyloids, for example, is a complicated process involving many species and levels of structures. This complexity, however, can be dealt with using statistical mechanical tools, such as free energies, partition functions, and transfer matrices. In this article, we review general strategies for studying protein aggregation using statistical mechanical approaches and show that canonical and grand canonical ensembles can be used in such approaches. The grand canonical approach is particularly convenient since competing pathways of assembly and dis-assembly can be considered simultaneously. Another advantage of using statistical mechanics is that numerically exact solutions can be obtained for all of the thermodynamic properties of fibrils, such as the amount of fibrils formed, as a function of initial protein concentration. Furthermore, statistical mechanics models can be used to fit experimental data when they are available for comparison.

John S. Schreck

2013-08-01

76

Lysozyme: a model protein for amyloid research.  

Science.gov (United States)

Ever since lysozyme was discovered by Fleming in 1922, this protein has emerged as a model for investigations on protein structure and function. Over the years, several high-resolution structures have yielded a wealth of structural data on this protein. Extensive studies on folding of lysozyme have shown how different regions of this protein dynamically interact with one another. Data is also available from numerous biotechnological studies wherein lysozyme has been employed as a model protein for recovering active recombinant protein from inclusion bodies using small molecules like l-arginine. A variety of conditions have been developed in vitro to induce fibrillation in hen lysozyme. They include (a) acidic pH at elevated temperature, (b) concentrated solutions of ethanol, (c) moderate concentrations of guanidinium hydrochloride at moderate temperature, and (d) alkaline pH at room temperature. This review aims to bring together similarities and differences in aggregation mechanisms, morphology of aggregates, and related issues that arise using the different conditions mentioned above to improve our understanding. The alkaline pH condition (pH 12.2), discovered and studied extensively in our lab, shall receive special attention. More than a decade ago, it was revealed that mutations in human lysozyme can cause accumulation of large quantities of amyloid in liver, kidney, and other regions of gastrointestinal tract. Understanding the mechanism of lysozyme aggregation will probably have therapeutic implications for the treatment of systemic nonneuropathic amyloidosis. Numerous studies have begun to focus attention on inhibition of lysozyme aggregation using antibody or small molecules. The enzymatic activity of lysozyme presents a convenient handle to quantify the native population of lysozyme in a sample where aggregation has been inhibited. The rich information available on lysozyme coupled with the multiple conditions that have been successful in inducing/inhibiting its aggregation in vitro makes lysozyme an ideal model protein to investigate amyloidogenesis. PMID:21846563

Swaminathan, Rajaram; Ravi, Vijay Kumar; Kumar, Satish; Kumar, Mattaparthi Venkata Satish; Chandra, Nividh

2011-01-01

77

SERF Protein Is a Direct Modifier of Amyloid Fiber Assembly  

Directory of Open Access Journals (Sweden)

Full Text Available The inherent cytotoxicity of aberrantly folded protein aggregates contributes substantially to the pathogenesis of amyloid diseases. It was recently shown that a class of evolutionary conserved proteins, called MOAG-4/SERF, profoundly alter amyloid toxicity via an autonomous but yet unexplained mode. We show that the biological function of human SERF1a originates from its atypical ability to specifically distinguish between amyloid and nonamyloid aggregation. This inherently unstructured protein directly affected the aggregation kinetics of a broad range of amyloidogenic proteins in vitro, while being inactive against nonamyloid aggregation. A representative biophysical analysis of the SERF1a:?-synuclein (aSyn complex revealed that the amyloid-promoting activity resulted from an early and transient interaction, which was sufficient to provoke a massive increase of soluble aSyn amyloid nucleation templates. Therefore, the autonomous amyloid-modifying activity of SERF1a observed in living organisms relies on a direct and dedicated manipulation of the early stages in the amyloid aggregation pathway.

S. Fabio Falsone

2012-08-01

78

[On functional amyloids of muscle proteins of titin family].  

Science.gov (United States)

In this review basic characteristics of amyloidoses, conformational diseases of human and animals are given. Properties of amyloids formed by titin family proteins and their possible functional role are discussed by example of mammal hibernation. PMID:23136766

Poddubnaia, Z A; Bobylëv, A G

2012-01-01

79

Molecular mechanisms of fibrillogenesis and the protective role of amyloid P component: Two possible avenues for therapy  

OpenAIRE

Amyloid deposits regress when the supply of fibril precursor proteins is sufficiently reduced, indicating that amyloid fibrils are degradable in vivo. Serum amyloid P component (SAP), a universal constituent of amyloid deposits, efficiently protects amyloid fibrils from proteolysis in vitro, and may contribute to persistence of amyloid in vivo. Drugs that prevent binding of SAP to amyloid fibrils in vivo should therefore promote regression of amyloid and we are actively seeking such agents. A...

Pepys, Mb; Tennent, Ga; Booth, Dr; Bellotti, V.; Lovat, Lb; Tan, Sy; Persey, MR; Hutchinson, Wl; Booth, Se; Madhoo, S.; Soutar, Ak; Hawkins, Pn; Zyl-smit, R.; Campistol, Jm; Fraser, Pe

1996-01-01

80

Use of serum amyloid A and milk amyloid A in the diagnosis of subclinical mastitis in dairy cows.  

Science.gov (United States)

Mastitis is the most frequent and costly disease in dairy herds, as it negatively affects yield and milk quality. The presence of clinical mastitis is quite easy to asses, whereas the diagnosis of the subclinical form can be more difficult and requires laboratory assays. Somatic cell count (SCC) is widely used as a rapid and low-cost indicator of mastitis, even if is not useful in discriminating between the clinical and subclinical form. As amyloid A has been investigated as a marker of mastitis, the aim of this study was to assess the potential value of measuring amyloid A in serum and milk and the correlation with SCC in the diagnosis of subclinical mastitis. The reliability of two different ELISA kits for the measurement of amyloid A in milk was also tested. During a 1-month trial period, 21 cows were assigned to three experimental groups according to their health status: 6 cows with clinical mastitis (CM), 10 cows with subclinical mastitis (SM) and 5 healthy cows (HE). Amyloid A was measured both in serum (SAA) and in quarter milk samples (mAA) with a serum ELISA kit, and in quarter milk samples (MAA) with a milk ELISA kit. SCC, total microbial count (TMC) and bacterial examination of the milk were also carried out. After a log transformation, the data were submitted to ANOVA and linear regression. TMC was significantly higher in cows with clinical mastitis, while no differences were observed between the other two experimental groups. SCC and MAA levels were significantly different among the three groups. mAA concentrations were similar between cows with subclinical and clinical mastitis, and SAA was not affected by mastitis. A significant correlation between SCC and MAA or mAA was detected, while no correlation was recorded between SAA and mAA. A close relationship between MAA and mAA was noticeable even at low concentrations, suggesting MAA as a potential physiological marker of subclinical mastitis. PMID:19638262

Gerardi, Gabriele; Bernardini, Daniele; Azzurra Elia, Carla; Ferrari, Vanni; Iob, Luciano; Segato, Severino

2009-11-01

81

MetAmyl: A METa-Predictor for AMYLoid Proteins  

OpenAIRE

The aggregation of proteins or peptides in amyloid fibrils is associated with a number of clinical disorders, including Alzheimer's, Huntington's and prion diseases, medullary thyroid cancer, renal and cardiac amyloidosis. Despite extensive studies, the molecular mechanisms underlying the initiation of fibril formation remain largely unknown. Several lines of evidence revealed that short amino-acid segments (hot spots), located in amyloid precursor proteins act as seeds for fibril elongation....

Emily, Mathieu; Talvas, Anthony; Delamarche, Christian

2013-01-01

82

Brazilin inhibits amyloid ?-protein fibrillogenesis, remodels amyloid fibrils and reduces amyloid cytotoxicity  

Science.gov (United States)

Soluble amyloid ?-protein (A?) oligomers, the main neurotoxic species, are predominantly formed from monomers through a fibril-catalyzed secondary nucleation. Herein, we virtually screened an in-house library of natural compounds and discovered brazilin as a dual functional compound in both A?42 fibrillogenesis inhibition and mature fibril remodeling, leading to significant reduction in A?42 cytotoxicity. The potent inhibitory effect of brazilin was proven by an IC50 of 1.5 ± 0.3??M, which was smaller than that of (?)-epigallocatechin gallate in Phase III clinical trials and about one order of magnitude smaller than those of curcumin and resveratrol. Most importantly, it was found that brazilin redirected A?42 monomers and its mature fibrils into unstructured A? aggregates with some ?-sheet structures, which could prevent both the primary nucleation and the fibril-catalyzed secondary nucleation. Molecular simulations demonstrated that brazilin inhibited A?42 fibrillogenesis by directly binding to A?42 species via hydrophobic interactions and hydrogen bonding and remodeled mature fibrils by disrupting the intermolecular salt bridge Asp23-Lys28 via hydrogen bonding. Both experimental and computational studies revealed a different working mechanism of brazilin from that of known inhibitors. These findings indicate that brazilin is of great potential as a neuroprotective and therapeutic agent for Alzheimer's disease. PMID:25613018

Du, Wen-Jie; Guo, Jing-Jing; Gao, Ming-Tao; Hu, Sheng-Quan; Dong, Xiao-Yan; Han, Yi-Fan; Liu, Fu-Feng; Jiang, Shaoyi; Sun, Yan

2015-01-01

83

Brazilin inhibits amyloid ?-protein fibrillogenesis, remodels amyloid fibrils and reduces amyloid cytotoxicity  

Science.gov (United States)

Soluble amyloid ?-protein (A?) oligomers, the main neurotoxic species, are predominantly formed from monomers through a fibril-catalyzed secondary nucleation. Herein, we virtually screened an in-house library of natural compounds and discovered brazilin as a dual functional compound in both A?42 fibrillogenesis inhibition and mature fibril remodeling, leading to significant reduction in A?42 cytotoxicity. The potent inhibitory effect of brazilin was proven by an IC50 of 1.5 +/- 0.3 ?M, which was smaller than that of (-)-epigallocatechin gallate in Phase III clinical trials and about one order of magnitude smaller than those of curcumin and resveratrol. Most importantly, it was found that brazilin redirected A?42 monomers and its mature fibrils into unstructured A? aggregates with some ?-sheet structures, which could prevent both the primary nucleation and the fibril-catalyzed secondary nucleation. Molecular simulations demonstrated that brazilin inhibited A?42 fibrillogenesis by directly binding to A?42 species via hydrophobic interactions and hydrogen bonding and remodeled mature fibrils by disrupting the intermolecular salt bridge Asp23-Lys28 via hydrogen bonding. Both experimental and computational studies revealed a different working mechanism of brazilin from that of known inhibitors. These findings indicate that brazilin is of great potential as a neuroprotective and therapeutic agent for Alzheimer's disease.

Du, Wen-Jie; Guo, Jing-Jing; Gao, Ming-Tao; Hu, Sheng-Quan; Dong, Xiao-Yan; Han, Yi-Fan; Liu, Fu-Feng; Jiang, Shaoyi; Sun, Yan

2015-01-01

84

Serum Amyloid A as a Predictive Marker for Radiation Pneumonitis in Lung Cancer Patients  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To investigate serum markers associated with radiation pneumonitis (RP) grade ?3 in patients with lung cancer who were treated with radiation therapy. Methods and Materials: Pretreatment serum samples from patients with stage Ib-IV lung cancer who developed RP within 1 year after radiation therapy were analyzed to identify a proteome marker able to stratify patients prone to develop severe RP by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Dosimetric parameters and 3 biological factors were compared. Results: Serum samples from 16 patients (28%) with severe RP (grade 3-4) and 42 patients (72%) with no or mild RP (grade 0-2) were collected for analysis. All patients received a median of 54 Gy (range, 42-70 Gy) of three-dimensional conformal radiation therapy with a mean lung dose (MLD) of 1502 cGy (range, 700-2794 cGy). An m/z peak of 11,480 Da was identified by SELDI-TOF-MS, and serum amyloid A (SAA) was the primary splitter serum marker. The receiver operating characteristic area under the curve of SAA (0.94; 95% confidence interval [CI], 0.87-1.00) was higher than those of C-reactive protein (0.83; 95% CI, 0.72-0.94), interleukin-6 (0.79; 95% CI, 0.65-0.94), and MLD (0.57; 95% CI, 0.37-0.77). The best sensitivity and specificity of combined SAA and MLD for predicting RP were 88.9% and 96.0%, respectively. Conclusions: Baseline SAA could be used as an auxiliary marker for predicting severe RP. Extreme care should be taken to limit the lung irradiation dose in patients with high SAA.

Wang, Yu-Shan [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Department of Animal Science, National Ilan University, Ilan, Taiwan (China); Chang, Heng-Jui [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Chang, Yue-Cune [Department of Mathematics, Tamkang University, Taipei, Taiwan (China); Huang, Su-Chen; Ko, Hui-Ling; Chang, Chih-Chia [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Yeh, Yu-Wung; Jiang, Jiunn-Song [Department of Chest Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Lee, Cheng-Yen; Chi, Mau-Shin [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Chi, Kwan-Hwa, E-mail: M006565@ms.skh.org.tw [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Institute of Radiation Science and School of Medicine, National Yang-Ming University, Taipei, Taiwan (China)

2013-03-01

85

Serum Amyloid A as a Predictive Marker for Radiation Pneumonitis in Lung Cancer Patients  

International Nuclear Information System (INIS)

Purpose: To investigate serum markers associated with radiation pneumonitis (RP) grade ?3 in patients with lung cancer who were treated with radiation therapy. Methods and Materials: Pretreatment serum samples from patients with stage Ib-IV lung cancer who developed RP within 1 year after radiation therapy were analyzed to identify a proteome marker able to stratify patients prone to develop severe RP by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Dosimetric parameters and 3 biological factors were compared. Results: Serum samples from 16 patients (28%) with severe RP (grade 3-4) and 42 patients (72%) with no or mild RP (grade 0-2) were collected for analysis. All patients received a median of 54 Gy (range, 42-70 Gy) of three-dimensional conformal radiation therapy with a mean lung dose (MLD) of 1502 cGy (range, 700-2794 cGy). An m/z peak of 11,480 Da was identified by SELDI-TOF-MS, and serum amyloid A (SAA) was the primary splitter serum marker. The receiver operating characteristic area under the curve of SAA (0.94; 95% confidence interval [CI], 0.87-1.00) was higher than those of C-reactive protein (0.83; 95% CI, 0.72-0.94), interleukin-6 (0.79; 95% CI, 0.65-0.94), and MLD (0.57; 95% CI, 0.37-0.77). The best sensitivity and specificity of combined SAA and MLD for predicting RP were 88.9% and 96.0%, respectively. Conclusions: Baseline SAA could be used as an auxiliary marker for predicting severe RP. Extreme care should be taken to limit the lung irradiation dose in patients with high SAA

86

Formation of soluble amyloid oligomers and amyloid fibrils by the multifunctional protein vitronectin  

OpenAIRE

Abstract Background The multifunctional protein vitronectin is present within the deposits associated with Alzheimer disease (AD), age-related macular degeneration (AMD), atherosclerosis, systemic amyloidoses, and glomerulonephritis. The extent to which vitronectin contributes to amyloid formation within these plaques, which contain misfolded, amyloidogenic proteins, and the role of vitronectin in the pathophysiology of the aforementioned diseases is currently unknown. The in...

Langen Ralf; Glabe Charles G; Kayed Rakez; Hsieh Chia-Ling; Mario, Isas J.; Shin Thuzar M; Chen Jeannie

2008-01-01

87

Inhibition of dynamin-dependent endocytosis increases shedding of the amyloid precursor protein ectodomain and reduces generation of amyloid ? protein  

OpenAIRE

Abstract Background The amyloid precursor protein (APP) is transported via the secretory pathway to the cell surface, where it may be cleaved within its ectodomain by ?-secretase, or internalized within clathrin-coated vesicles. An alternative proteolytic pathway occurs within the endocytic compartment, where the sequential action of ?- and ?-secretases generates the amyloid ? protein (A?). In this study, we investigated the effects of modulators of endocytosis on APP pr...

Lopez-Coviella Ignacio; Balcz Brigitte A; Carey Robyn M; Slack Barbara E

2005-01-01

88

Serum amyloid A binds specific extracellular matrix glycoproteins and induces the adhesion of resting CD4+ T cells.  

Science.gov (United States)

Serum amyloid A (SAA), a prototypic acute phase protein reactant, exists naturally in the serum of healthy individuals. However, the levels of SAA in serum and its presence in sites of inflammation increase during certain chronic diseases associated with a local elevation of cytokine concentrations. Although the chemical structure of SAA is defined, its putative immunologic role(s) is still obscure. Nevertheless, it has been shown that 1) SAA acts as a chemoattractant and regulator of the migration of monocytes, polymorphonuclear cells, and T lymphocytes through endothelial cell monolayers; and 2) SAA and its proteolytically degraded N-terminal amyloid A fragment contain an extracellular matrix (ECM)-related cell adhesion epitopes. Herein, we examined whether SAA can associate with specific ECM moieties, and whether immobilized SAA-ECM complexes affect T lymphocyte adhesion. Radiolabeled human rSAA ([125I]rSAA) interacted avidly (Kd = 10(-9) M) and transiently with intact ECM, laminin, and vitronectin, but not with fibronectin or collagen type II. The binding of [125I]rSAA to ECM and laminin was inhibited by unlabeled rSAA and by the AA fragment, but not by the C-terminal portion of SAA (amino acid residues 2-82 and 77-104, respectively). Upon interactions with SAA or amyloid A, immobilized ECM, laminin, and vitronectin induced the adhesion of resting human CD4+ T cells in an apparently beta 1-integrin-mediated manner. Thus, the ECM appears to serve as a temporary anchorage site for SAA and amyloid A, and these ECM-complexed molecules seem to be involved in regulating the recruitment and accumulation of immunocytes in extravascular inflammatory compartments. PMID:8557997

Preciado-Patt, L; Hershkoviz, R; Fridkin, M; Lider, O

1996-02-01

89

Haptoglobin and serum amyloid a in subacute ruminal acidosis in goats  

Directory of Open Access Journals (Sweden)

Full Text Available Ruminal acidosis is a frequent disorder that occurs in goats as a consequence of feedingmistakes in animals not adapted to a diet of easily fermentable carbohydrates. The subacuteform of the disease is difficult to diagnose because no apparent signs are shownand the acid-base parameters may remain within the normal range. The present studyaimed at testing the hypothesis that haptoglobin (Hp and serum amyloid A (SAA,the two major acute phase proteins in ruminants, may be useful as markers of subacuteacidosis in goats.A subacute acidosis was induced in six Murciano-Granadina goats through a diet of60% mixed feed-40% alfalfa hay offered during 5 days to goats not adapted to eatmixed feed. Two goats were rumen-fistulated to investigate the effect of feeding onruminal pH. Sampling of blood and urine of all animals was done before the inductionof the acidosis, during 5 days after the onset of induction and for 18 days after theinduction (recovery period.Ruminal pH in the fistulated goats dropped to less than 5.5 during the inductionperiod, and half of the goats had diarrhea on the third day after the induction of acidosis.Acid-base parameters showed that the acid-base compensatory mechanisms wereefficient in maintaining the equilibrium. Serum Hp had a moderate increase duringthe induction period, while SAA did not change. These results suggest that Hp mightbe a potential marker for ruminal acidosis in goats.

F.H.D. González

2010-12-01

90

Serum amyloid A and haptoglobin concentrations in serum and peritoneal fluid of healthy horses and horses with acute abdominal pain  

DEFF Research Database (Denmark)

BACKGROUND: Peritoneal fluid (PF) analysis is a valuable diagnostic tool in equine medicine. Markers such as serum amyloid A (SAA) and haptoglobin (Hp) could facilitate the diagnosis of inflammatory abdominal conditions. OBJECTIVES: The objectives were to (1) establish reference intervals (RI) for SAA and Hp in serum and PF in healthy horses, (2) compare SAA and Hp concentrations between healthy horses and horses with colic, and (3) to assess the correlation between serum and PF concentrations. METHODS: Serum amyloid A and Hp concentrations were determined by automated assays in prospectively enrolled healthy reference horses and horses with colic. RIs were calculated, group concentrations were compared by Student's t-test, and Pearson's correlation for serum and PF concentrations were determined. RESULTS: In healthy horses (n = 62) the measurements for SAA were below the detection limit (0.5 mg/L) in 94% of serum samples and 98% of PF samples. Horses with colic (n = 61) had statistically significantly increased SAA concentrations in serum (P 

Pihl, Tina Holberg; Andersen, Pia Haubro

2013-01-01

91

Complement activation by the amyloid proteins A beta peptide and beta 2-microglobulin  

DEFF Research Database (Denmark)

Complement activation (CA) has been reported to play a role in the pathogenesis of Alzheimer's disease (AD). To investigate whether CA may contribute to amyloidogenesis in general, the CA potential of different amyloid fibril proteins was tested. CA induced by A beta preparations containing soluble protein, protofilaments and some fibrils or only fibrils in a solid phase system (ELISA) was modest with a slow kinetics compared to the positive delta IgG control. Soluble A beta induced no detectable CA in a liquid phase system (complement consumption assay) while fibrillar A beta caused CA at 200 mg/ml and higher concentrations. Soluble beta 2-microglobulin (beta 2M) purified from peritoneal dialysates was found to be as potent a complement activator as A beta in both solid and liquid phase systems while beta 2M purified from urine exhibited lower activity, a difference which may be explained by differences observed in SDS-resistant oligomers and isoforms. Soluble Amyloid A-protein caused no significant CA. A beta and beta 2M activated complement via the classical pathway. The modifying influence by amyloid-associated molecules on A beta-induced CA was also investigated, but neither serum amyloid P component nor heparan sulfate did significantly alter the A beta-induced CA. The results indicate that not only fibrillar A beta but also oligomers of, in particular, beta 2M from patients with dialysis-associated amyloidosis are capable of inducing CA at supra-physiological concentrations.

Nybo, Mads; Nielsen, E H

1999-01-01

92

Amyloid formation and inhibition of an all-beta protein: A study on fungal polygalacturonase  

Science.gov (United States)

Theoretically, all proteins can adopt the nanofibrillar structures known as amyloid, which contain cross-beta structures. The all-beta folded proteins are particularly interesting in this regard, since they appear to be naturally more predisposed toward this structural arrangement. In this study, methanol has been used to drive the beta-helix protein polygalacturonase (PG), toward amyloid fibril formation. Congo red absorbance, thioflavin T fluorescence, circular dichroism (CD) and transmission electron microscopy have been used to characterize this process. Similar to other all-beta proteins, PG shows a non-cooperative fibrillation mechanism, but the structural changes that are monitored by CD indicate a different pattern. Furthermore, several compounds containing aromatic components were tested as potential inhibitors of amyloid formation. Another protein predominantly composed of alpha-helices (human serum albumin) was also targeted by these ligands, in order to get an insight into their potential anti-aggregation property toward structurally different proteins. Among tested compounds, silibinin and chlorpropamide were able to considerably affect both proteins fibrillation process.

Chinisaz, Maryam; Ghasemi, Atiyeh; Larijani, Bagher; Ebrahim-Habibi, Azadeh

2014-02-01

93

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

DEFF Research Database (Denmark)

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 amyloidA, 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.

Depauw, Sarah; Delanghe, Joris

2014-01-01

94

Modification of a small ?-barrel protein, to give pseudo-amyloid structures, inhibits amyloid ?-peptide aggregation.  

Science.gov (United States)

Aggregation of amyloid ?-peptide (A?) is closely related to the pathogenesis of Alzheimer's disease (AD). Although much effort has been devoted to the construction of molecules that inhibit the aggregation of A?1-42, high doses are needed for the inhibition of A? aggregation in many cases. Previously, we reported that designed green fluorescent protein (GFP) analogues that gives pseudo-A? ?-sheet structures can work as an aggregation inhibitor against A?. To further test this design strategy, we constructed protein analogues that mimic A? ?-sheet structures of amyloids by using insulin-like growth factor 2 receptor domain 11 (IGF2R-d11) as a scaffold. A designed protein, named IG11KK, which has a parallel configuration of A?-like ? sheets, can bind more preferentially to oligomeric A?1-42 than the monomer. Moreover, IG11KK suppressed the aggregation of A?1-42 efficiently, even though lower concentrations of IG11KK than A? were used. The aggregation kinetics of A? in the presence of the designed proteins revealed that IG11KK can work as an inhibitor not only for the early to middle stages, but also in the latter stage of A? aggregation owing to its favorable binding to oligomeric structures of A?. The design strategy using ?-barrel proteins such as IGF2R-d11 and GFP is useful in generating excellent inhibitors of protein misfolding and amyloid formation. PMID:23371795

Murakoshi, Yuko; Takahashi, Tsuyoshi; Mihara, Hisakazu

2013-04-01

95

Anti-serum amyloid component P antibodies in patients with systemic lupus erythematosus correlate with disease activity  

OpenAIRE

Objective: To determine the presence of raised titres of anti-serum amyloid P component (SAP) antibodies in patients with systemic lupus erythematosus (SLE) and to evaluate their correlation with clinical disease by the SLEDAI and clinical manifestations.

Zandman-goddard, G.; Blank, M.; Langevitz, P.; Slutsky, L.; Pras, M.; Levy, Y.; Shovman, O.; Witte, T.; Doria, A.; Rovensky, J.; Shoenfeld, Y.

2005-01-01

96

Characterization of serum amyloid A (SAA) in rainbow trout using a new monoclonal antibody.  

Science.gov (United States)

Serum amyloid A (SAA) is an integral part of the innate immune response in mammals and considered to be important during the acute phase response. The present study was undertaken to elucidate the role of SAA protein in the innate immune response of rainbow trout. A monoclonal antibody raised against a recombinant peptide of rainbow trout SAA was characterized using Western blot, dot blot, ELISA and immunohistochemistry. SAA association with high density lipoprotein (HDL) complicated band identification in Western blot, but delipidization of the SAA-HDL isolate highly increased the quality of reaction in the western blot. Rainbow trout fry (87 days post hatch) infected with Yersinia ruckeri showed a significant up-regulation of the SAA gene at 72 h post infection with an increase until 96 h post infection. Non-significant up-regulations were seen at earlier time points i.e. 4 and 24 h. The expression pattern of SAA significantly correlated to the immunohistochemical analysis of the infected fry. A weak staining was seen in liver tissue at 4 h post infection which increased in intensity during the course of infection i.e. 24, 72 and 96 h post infection. PMID:25149592

Kania, Per W; Chettri, Jiwan K; Buchmann, Kurt

2014-10-01

97

Tensile deformation and failure of amyloid and amyloid-like protein fibrils  

Science.gov (United States)

Here we report a series of full atomistic molecular dynamics simulations of six amyloid or amyloid-like protein fibrils in order to systematically understand the effect of different secondary structure motifs on the mechanical tensile and failure response of cross-\\beta protein fibrils. We find a similar failure behavior across the six structures; an initial failure event occurs at small strains involving cooperative rupture of a group of hydrogen bonds, followed by a slow one-by-one hydrogen bond rupture process as the remaining \\beta -sheets peel off with very low applied stress. We also find that the ultimate tensile strength of the protein fibrils investigated scales directly with the number of hydrogen bonds per unit area which break in the initial rupture event. Our results provide insights into structure-property relationships in protein fibrils important for disease and engineering applications and lay the groundwork for the development of materials selection criteria for the design of de novo amyloid-based functional biomaterials.

Solar, Max; Buehler, Markus J.

2014-03-01

98

Haptoglobin and serum amyloid A in relation to the somatic cell count in quarter, cow composite and bulk tank milk samples  

OpenAIRE

Milk somatic cell count (SCC) is the gold standard in diagnosis of subclinical mastitis, and is also an important parameter in quality programmes of dairy cooperatives. As routine SCC analysis is usually restricted to central laboratories, much effort has been invested in the search for alternative biomarkers of mastitis and milk quality, including the presence in the milk of the acute phase proteins (APP), haptoglobin (Hp) and serum amyloid A (SAA). The aim of this study was to investigate r...

A?kerstedt, Maria; Persson Waller, Karin; Sternesjo?, A?se

2007-01-01

99

Engineering Amyloid Fibrils from ?-Solenoid Proteins for Biomaterials Applications.  

Science.gov (United States)

Nature provides numerous examples of self-assembly that can potentially be implemented for materials applications. Considerable attention has been given to one-dimensional cross-? or amyloid structures that can serve as templates for wire growth or strengthen materials such as glue or cement. Here, we demonstrate controlled amyloid self-assembly based on modifications of ?-solenoid proteins. They occur naturally in several contexts (e.g., antifreeze proteins, drug resistance proteins) but do not aggregate in vivo due to capping structures or distortions at their ends. Removal of these capping structures and regularization of the ends of the spruce budworm and rye grass antifreeze proteins yield micron length amyloid fibrils with predictable heights, which can be a platform for biomaterial-based self-assembly. The design process, including all-atom molecular dynamics simulations, purification, and self-assembly procedures are described. Fibril formation with the predicted characteristics is supported by evidence from thioflavin-T fluorescence, circular dichroism, dynamic light scattering, and atomic force microscopy. Additionally, we find evidence for lateral assembly of the modified spruce budworm antifreeze fibrils with sufficient incubation time. The kinetics of polymerization are consistent with those for other amyloid formation reactions and are relatively fast due to the preformed nature of the polymerization nucleus. PMID:25562726

Peralta, Maria D R; Karsai, Arpad; Ngo, Alice; Sierra, Catherine; Fong, Kai T; Hayre, Natha Robert; Mirzaee, Nima; Ravikumar, Krishnakumar Mayuram; Kluber, Alexander J; Chen, Xi; Liu, Gang-Yu; Toney, Michael D; Singh, Rajiv R; Cox, Daniel Lee

2015-01-27

100

Zn2+ interaction with Alzheimer amyloid beta protein calcium channels.  

OpenAIRE

The Alzheimer disease 40-residue amyloid beta protein (AbetaP[1-40]) forms cation-selective channels across acidic phospholipid bilayer membranes with spontaneous transitions over a wide range of conductances ranging from 40 to 4000 pS. Zn2+ has been reported to bind to AbetaP[1-40] with high affinity, and it has been implicated in the formation of amyloid plaques. We now report the functional consequences of such Zn2+ binding for the AbetaP[1-40] channel. Provided the AbetaP[1-40] channel is...

Arispe, N.; Pollard, H. B.; Rojas, E.

1996-01-01

101

Enhanced degradation of amyloid AA proteins by enzyme activation: a possible model for a therapeutic approach  

International Nuclear Information System (INIS)

The capacity of plasminogen from human serum to degrade amyloid AA protein was tested using radiolabelled protein AA coupled to cyanogen bromide activated Sepharose 6 MB as substrate. Protein AA degrading activity was determined in fractions of normal human serum separated by Sephadex G 150. Each fraction was tested in the presence and absence of the plasminogen activator streptokinase. The AA degrading activity was markedly increased in fractions in which plasminogen activation had occurred. These fractions were also the same as those showing the presence of plasminogen as demonstrated by reaction with a specific anti-plasminogen antiserum. Moreover, the increase in AA degrading activity could be inhibited with antibodies to plasminogen. AA degrading activity could also be enhanced in whole human plasma by streptokinase activation

102

AMYPdb: A database dedicated to amyloid precursor proteins  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Misfolding and aggregation of proteins into ordered fibrillar structures is associated with a number of severe pathologies, including Alzheimer's disease, prion diseases, and type II diabetes. The rapid accumulation of knowledge about the sequences and structures of these proteins allows using of in silico methods to investigate the molecular mechanisms of their abnormal conformational changes and assembly. However, such an approach requires the collection of accurate data, which are inconveniently dispersed among several generalist databases. Results We therefore created a free online knowledge database (AMYPdb dedicated to amyloid precursor proteins and we have performed large scale sequence analysis of the included data. Currently, AMYPdb integrates data on 31 families, including 1,705 proteins from nearly 600 organisms. It displays links to more than 2,300 bibliographic references and 1,200 3D-structures. A Wiki system is available to insert data into the database, providing a sharing and collaboration environment. We generated and analyzed 3,621 amino acid sequence patterns, reporting highly specific patterns for each amyloid family, along with patterns likely to be involved in protein misfolding and aggregation. Conclusion AMYPdb is a comprehensive online database aiming at the centralization of bioinformatic data regarding all amyloid proteins and their precursors. Our sequence pattern discovery and analysis approach unveiled protein regions of significant interest. AMYPdb is freely accessible 1.

Delamarche Christian

2008-06-01

103

Amyloid oligomers: spectroscopic characterization of amyloidogenic protein states.  

Science.gov (United States)

It is assumed that protein fibrils manifested in amyloidosis result from an aggregation reaction involving small misfolded protein sequences being in an 'oligomeric' or 'prefibrillar' state. This review covers recent optical spectroscopic studies of amyloid protein misfolding, oligomerization and amyloid fibril growth. Although amyloid fibrils have been studied using established protein-characterization techniques throughout the years, their oligomeric precursor states require sensitive detection in real-time. Here, fluorescent staining is commonly performed using thioflavin T and other small fluorescent molecules such as 4-(dicyanovinyl)- julolidine and 1-amino-8-naphtalene sulphonate that have high affinity to hydrophobic patches. Thus, populated oligomeric intermediates and related 'prefibrillar structures' have been reported for several human amyloidogenic systems, including amyloid-beta protein, prion protein, transthyretin, alpha-synuclein, apolipoprotein C-II and insulin. To obtain information on the progression of the intermediate states, these were monitored in terms of fluorescence parameters, such as anisotropy, and quantum efficiency changes upon protein binding. Recently, new antibody stains have allowed precise monitoring of the oligomer size and distributions using multicolor labelling and single molecule detection. Moreover, a pentameric thiophene derivative (p-FTAA) was reported to indicate early precursors during A-beta(1-40) fibrillation, and was also demonstrated in real-time visualization of cerebral protein aggregates in transgenic AD mouse models by multiphoton microscopy. Conclusively, molecular probes and optical spectroscopy are now entering a phase enabling the in vivo interrogation of the role of oligomers in amyloidosis. Such techniques used in parallel with in vitro experiments, of increasing detail, will probably couple structure to pathogenesis in the near future. PMID:20148961

Lindgren, Mikael; Hammarström, Per

2010-03-01

104

Role of water in Protein Aggregation and Amyloid Polymorphism  

OpenAIRE

A variety of neurodegenerative diseases are associated with the formation of amyloid plaques. Our incomplete understanding of this process underscores the need to decipher the principles governing protein aggregation. Most experimental and simulation studies have been interpreted largely from the perspective of proteins: the role of solvent has been relatively overlooked. In this Account, we provide a perspective on how interactions with water affect folding landscapes of ...

Thirumalai, D.; Reddy, Govardhan; Straub, John E.

2012-01-01

105

Scintigraphic imaging and turnover studies with iodine-131 labelled serum amyloid P component in systemic amyloidosis  

International Nuclear Information System (INIS)

Radiolabelled serum amyloid P component (SAP) is a specific tracer for amyloid. Iodine-123 has ideal physical characteristics for scintigraphy but is expensive and not widely available. Here we report serial imaging and turnover studies in which we labelled SAP with iodine-131, a cheap alternative isotope which would be expected to yield poorer images but permit more prolonged turnover measurements. Imaging and plasma clearance and whole body retention (WBR) of tracer were studied for up to 7 days in ten patients with proven systemic AL amyloidosis and two patients in whom the diagnosis was suspected, after i.v. administration of about 37 MBq of 131I-SAP. Normal blood pool images were obtained in the latter two subjects and amyloidosis was subsequently refuted histologically. WBR at 48 h was 65% of the injected dose (i.d.). Among the other ten patients, amyloid deposits were identified in the spleen in eight cases, liver in five and kidneys in four; other sites that gave positive results included bone, joints and soft tissues, and the myocardium in one case. Up to 95% of the tracer localised into amyloid within 6-h, and the values for WBR became progressively more discriminating during the study period, exceeding the normal reference value (131I-SAP produced diagnostic scans in every patient in this series and, coupled with the detailed turnover information, is adequate for monitoring disease progress. (orig.)

106

Oxysterol-binding protein-1 (OSBP1) modulates processing and trafficking of the amyloid precursor protein  

OpenAIRE

Background Evidence from biochemical, epidemiological and genetic findings indicates that cholesterol levels are linked to amyloid-? (A?) production and Alzheimer's disease (AD). Oxysterols, which are cholesterol-derived ligands of the liver X receptors (LXRs) and oxysterol binding proteins, strongly regulate the processing of amyloid precursor protein (APP). Although LXRs have been studied extensively, little is known about the biology of oxysterol binding proteins. Oxystero...

Seabrook Guy R; Ray William J; Suon Sokreine; Guillily Maria; Chen Ci-Di; Cordy Joanna M; Zerbinatti Celina V; Abraham Carmela R; Wolozin Benjamin

2008-01-01

107

Cerebral amyloid angiopathy  

Science.gov (United States)

Cerebral amyloid angiopathy is a neurological condition in which proteins called amyloid build up on the walls of the arteries ... The cause of cerebral amyloid angiopathy is unknown. Sometimes, it ... Persons with this condition have deposits of amyloid protein ...

108

Small Heat Shock Proteins Potentiate Amyloid Dissolution by Protein Disaggregases from Yeast and Humans  

OpenAIRE

The authors define how small heat-shock proteins synergize to regulate the assembly and disassembly of a beneficial prion, and then they exploit this knowledge to identify the human amyloid depolymerase.

Duennwald, Martin L.; Echeverria, Analisa; Shorter, James

2012-01-01

109

Administration of perioperative penicillin reduces postoperative serum amyloid A response in horses being castrated standing  

DEFF Research Database (Denmark)

Objectives: To compare postoperative in?ammatory responses in horses administered perioperative procaine penicillin and those not administered penicillin using acute phase protein serum amyloid A (SAA) as a marker of in?ammation. Study Design: Randomized clinical trial. Animals: Stallions (n = 50) castrated under ?eld conditions. Methods: SAA concentrations were determined on days 0, 3, and 8. Six horses were subsequently excluded because of elevated SAA concentrations on day 0. Of the remaining 50 horses, 26 were administered nonsteroidal anti-in?ammatory drug (NSAID) therapy and 24 were administered NSAID and 25,000 U/kg procaine penicillin on day 0, 1, and 2. Results: SAA concentrations increased signi?cantly from preoperative levels in both groups, and on day 8 concentrations were signi?cantly (P o .02) higher in horses administered only NSAID than in those administered procaine penicillin and NSAID. Infectious complications occurred more frequently (P o .01) in horses with preoperatively elevated SAA concentrations (the excluded horses) than in horses with normal preoperative SAA concentrations (the included horses). Conclusions: Perioperative antimicrobial therapy reduced the postoperative SAA response, suggesting that bacteria were present in the surgical wound and contributed to in?ammation after castration. Horses with elevated preoperative SAA concentrations developed infectious complications more often than horses with normal preoperative SAA concentrations. Clinical Relevance: Administration of antimicrobials may be important in horses being castrated standing under ?eld conditions. Increased SAA concentrations seem to be an indicator of increased surgical risk in horses and may be useful before elective surgery for planning.

Busk, Peter; Jacobsen, Stine

2010-01-01

110

Serum amyloid A1 isoforms display different efficacy at Toll-like receptor 2 and formyl peptide receptor 2.  

Science.gov (United States)

Serum amyloid A (SAA) is a major acute-phase protein and a precursor of amyloid A, the deposit of which leads to amyloidosis. Different alleles exist in SAA1, a predominant form of the human SAA gene family. Emerging evidence has shown correlations between these alleles and diseases including familiar Mediterranean fever and amyloidosis. However, it remains unclear how the proteins encoded by these SAA1 alleles act differently. Here we report the characterization of proteins encoded by SAA1.1, SAA1.3, and SAA1.5, in comparison to that encoded by SAA2.2, for their preference of the SAA receptors including formyl peptide receptor 2 (FPR2) and Toll-like receptor 2 (TLR2). SAA1.1 was more efficacious than SAA1.3 and SAA1.5 but equally efficacious to SAA2.2 in calcium mobilization and chemotaxis assays, which measure the activation of the G protein-coupled FPR2. In agreement with this, SAA1.1 and SAA2.2 induced more robust phosphorylation of ERK than SAA1.3 and SAA1.5. Only small differences were observed between the SAA1 proteins tested and SAA2.2 in TLR2-dependent NF-?B luciferase reporter assay. In comparison, SAA1.3 was most effective in stimulating ERK and p38 MAPK phosphorylation. Using bone marrow-derived macrophages from C57BL/10ScN (Tlr4lps-del) mice, we examined the SAA isoforms for their induction of selected pro- and anti-inflammatory cytokines. SAA1.3 was most potent in the induction of TNF? and IL-1rn, whereas SAA1.5 induced robust IL-10 expression. These results show differences of the SAA1 isoforms in their selectivity for the SAA receptors, which may affect their roles in modulating inflammation and immunity. PMID:25154907

Chen, Mingjie; Zhou, Huibing; Cheng, Ni; Qian, Feng; Ye, Richard D

2014-12-01

111

The effect of amyloid associated proteins on the expression of genes involved in amyloid-? clearance by adult human astrocytes.  

Science.gov (United States)

Astrocytes appear to be important mediators in the clearance of amyloid beta1-42 (A?), the key component of senile plaques characteristic of Alzheimer's disease (AD). Recently, we found the amyloid associated proteins (AAPs) ?1-antichymotrypsin (ACT), apolipoprotein J and E (ApoJ and ApoE) and a mixture of serum amyloid P (SAP) and C1q (SAP-C1q) to modify A?-uptake by human astrocytes. Here we investigated the effect of oligomeric (A?oligo) and fibrillar A? (A?fib), alone and in combination with a panel of AAPs on the astrocytic expression of genes proposed to be involved in A?-uptake and degradation. Primary human astrocytes (isolated from non-demented control (n=4) and AD patient (n=4) brain specimens) were exposed to either A?oligo or A?fib preparations with or without the above mentioned AAPs. Quantitative gene expression analysis of A?-receptors Scavenger receptor B1 (SCARB1), macrophage receptor with collagenous structure (MARCO) and low density lipoprotein receptor related protein-2 (LRP2 or megalin) as well as of A?-degrading enzymes neprilysin (NEP), insulin-degrading enzyme (IDE) and metalloproteinase-9 (MMP-9) was performed by real-time PCR. Basal expression of NEP, IDE and SCARB1 was easily detected whereas expression of MARCO, LRP2 and MMP-9 could only be detected upon pre-amplification. Basal expression of NEP, IDE and SCARB1 did not change upon exposure to A?oligo or A?fib alone in any of the investigated astrocyte cultures. Interestingly NEP expression was increased upon exposure to ApoE in combination with both A?-preparations, and also SCARB1 expression was induced upon treatment with ApoE in combination with A?fib in astrocytes from non-demented controls. Further, SAP-C1q increased SCARB1 expression in control astrocytes when combined with A?oligo. These alterations were not found in astrocytes from AD patients. Thus, we conclude that A? alone apparently does not affect the astrocytic expression of IDE, NEP or SCARB1. However, NEP and SCARB1 expression is increased in astrocytes from non-demented subjects when exposed to A? combined with AAPs like ApoE. These astrocytic gene expression-regulatory mechanisms appear to be defective in AD and thus might contribute to the development and progression of AD pathology. PMID:22101005

Mulder, Sandra D; Veerhuis, Robert; Blankenstein, Marinus A; Nielsen, Henrietta M

2012-01-01

112

Acute phase protein concentrations in serum and milk from healthy cows, cows with clinical mastitis and cows with extramammary inflammatory conditions  

DEFF Research Database (Denmark)

The concentrations of the two acute phase proteins, serum amyloid A and haptoglobin, in serum and milk were compared in 10 cows with clinical mastitis, 11 cows with extramammary inflammatory conditions and 10 clinically healthy control cows. The concentrations of both acute phase proteins were higher in the serum and milk of the cows with mastitis than in the cows in the other two groups. Four of the cows with extramammary inflammatory conditions had serum amyloid A concentrations in serum above 100 mug/ml, but negligible concentrations in milk, indicating that a pathogen must be present in the mammary gland for serum amyloid A to accumulate in milk. The acute phase protein concentrations in milk increased significantly with increasing somatic cell count, suggesting that they may be indicators of the severity of an infection.

Nielsen, B.H.; Jacobsen, S.

2004-01-01

113

Role of water in protein aggregation and amyloid polymorphism.  

Science.gov (United States)

A variety of neurodegenerative diseases are associated with amyloid plaques, which begin as soluble protein oligomers but develop into amyloid fibrils. Our incomplete understanding of this process underscores the need to decipher the principles governing protein aggregation. Mechanisms of in vivo amyloid formation involve a number of coconspirators and complex interactions with membranes. Nevertheless, understanding the biophysical basis of simpler in vitro amyloid formation is considered important for discovering ligands that preferentially bind regions harboring amyloidogenic tendencies. The determination of the fibril structure of many peptides has set the stage for probing the dynamics of oligomer formation and amyloid growth through computer simulations. Most experimental and simulation studies, however, have been interpreted largely from the perspective of proteins: the role of solvent has been relatively overlooked in oligomer formation and assembly to protofilaments and amyloid fibrils. In this Account, we provide a perspective on how interactions with water affect folding landscapes of amyloid beta (A?) monomers, oligomer formation in the A?16-22 fragment, and protofilament formation in a peptide from yeast prion Sup35. Explicit molecular dynamics simulations illustrate how water controls the self-assembly of higher order structures, providing a structural basis for understanding the kinetics of oligomer and fibril growth. Simulations show that monomers of A? peptides sample a number of compact conformations. The formation of aggregation-prone structures (N*) with a salt bridge, strikingly similar to the structure in the fibril, requires overcoming a high desolvation barrier. In general, sequences for which N* structures are not significantly populated are unlikely to aggregate. Oligomers and fibrils generally form in two steps. First, water is expelled from the region between peptides rich in hydrophobic residues (for example, A?16-22), resulting in disordered oligomers. Then the peptides align along a preferred axis to form ordered structures with anti-parallel ?-strand arrangement. The rate-limiting step in the ordered assembly is the rearrangement of the peptides within a confining volume. The mechanism of protofilament formation in a polar peptide fragment from the yeast prion, in which the two sheets are packed against each other and create a dry interface, illustrates that water dramatically slows self-assembly. As the sheets approach each other, two perfectly ordered one-dimensional water wires form. They are stabilized by hydrogen bonds to the amide groups of the polar side chains, resulting in the formation of long-lived metastable structures. Release of trapped water from the pore creates a helically twisted protofilament with a dry interface. Similarly, the driving force for addition of a solvated monomer to a preformed fibril is water release; the entropy gain and favorable interpeptide hydrogen bond formation compensate for entropy loss in the peptides. We conclude by offering evidence that a two-step model, similar to that postulated for protein crystallization, must also hold for higher order amyloid structure formation starting from N*. Distinct water-laden polymorphic structures result from multiple N* structures. Water plays multifarious roles in all of these protein aggregations. In predominantly hydrophobic sequences, water accelerates fibril formation. In contrast, water-stabilized metastable intermediates dramatically slow fibril growth rates in hydrophilic sequences. PMID:21761818

Thirumalai, D; Reddy, Govardhan; Straub, John E

2012-01-17

114

Insulin-degrading enzyme regulates the levels of insulin, amyloid ?-protein, and the ?-amyloid precursor protein intracellular domain in vivo  

OpenAIRE

Two substrates of insulin-degrading enzyme (IDE), amyloid ?-protein (A?) and insulin, are critically important in the pathogenesis of Alzheimer's disease (AD) and type 2 diabetes mellitus (DM2), respectively. We previously identified IDE as a principal regulator of A? levels in neuronal and microglial cells. A small chromosomal region containing a mutant IDE allele has been associated with hyperinsulinemia and glucose intolerance in a rat model of DM2. Human genetic studies have implicated...

Farris, Wesley; Mansourian, Stefan; Chang, Yang; Lindsley, Loren; Eckman, Elizabeth A.; Frosch, Matthew P.; Eckman, Christopher B.; Tanzi, Rudolph E.; Selkoe, Dennis J.; Gue?nette, Suzanne

2003-01-01

115

Decreases of apolipoprotein B-100 and A-I concentrations and induction of haptoglobin and serum amyloid A in nonfed calves.  

Science.gov (United States)

Reduced feed intake near parturition is suggested to be one of the major causal factors for the development of fatty liver in cows, and nonfeeding has been used as an experimental model for fatty liver. In cows with fatty liver, concentrations of lipoprotein lipids and proteins are decreased. In addition, the acute-phase protein haptoglobin is induced. The purpose of the present study was to examine whether the decrease of lipoprotein concentrations and the induction of acute-phase proteins were similarly reproduced by non-feeding. Holstein female calves (n=5) were nonfed for 3 days and thereafter refed. Serum concentrations of nonesterified fatty acids and beta-hydroxybutyric acid were initially increased by the nonfeeding, and followed by decreases in concentrations of cholesteryl esters, phospholipids, apolipoprotein (apo) B-100 and apoA-I. The apoC-III concentration was not distinctly decreased. Haptoglobin and serum amyloid A were induced during the nonfeeding and refeeding process. Haptoglobin was distributed in different proportions in the high-density lipoprotein, very high-density lipoprotein and the lipoprotein-deficient fractions, whereas almost all serum amyloid A was associated with the high-density lipoprotein fraction. These results suggest that the decreases in lipoprotein concentrations and induction of acute-phase proteins found in cows with fatty liver and those with fatty liver-related diseases such as ketosis are primarily due to the reduced feed intake near parturition. PMID:11853146

Katoh, Norio; Oikawa, Shin; Oohashi, Tsutai; Takahashi, Yuji; Itoh, Fumiaki

2002-01-01

116

Investigation of the solubility and the potentials for purification of serum amyloid A (SAA) from equine acute phase serum : a pilot study  

DEFF Research Database (Denmark)

BACKGROUND: Serum amyloid A (SAA) is useful as a diagnostic marker of systemic inflammation in horses, but only heterologous assays based on non-equine calibration and standardization are available for measurements of equine SAA. More accurate measurements could be obtained using purified species-specific SAA in native conformation for assay calibration and standardization. Further knowledge about the biochemical properties of SAA would facilitate a future production of native species-specific calibration material Therefore, the aim of the study was an investigation of the solubility and potentials for purification of equine SAA based on biochemical properties.Freeze dried equine acute phase serum was dissolved in 70% 2-propanol, 8 M urea, and milli-Q water, respectively. Supercritical fluid extraction (SFE), size-exclusive chromatography (FPLC-SEC), and preparative isoelectric focusing (IEF) were performed in the attempt to purify. Immunostaining of IEF blots were used for isoform-specific detection of SAA in the preparations and purity was assessed by silverstained SDS-PAGE. FINDINGS: SAA was soluble in 70% 2-propanol, 8 M urea and Milli-Q water. SAA was not separated in the lipophilic or ampipathic fractions following SFE. SAA was included in a FPLC-SEC-fraction of 237 kDa, despite the molecular weight known to be much smaller, suggesting binding to other serum constituents. SAA precipitated following separation of other serum proteins by preparative IEF. DISCUSSION: No effective purification of SAA was achieved in the present study, but findings important for future investigations were made. The study suggested that SAA is not exclusively hydrophobic, but appears less hydrophobic when interacting with other serum components. These results suggest more complex aspects of solubility than previously believed, and indicate potentials for purification of native SAA.

Christensen, Michelle BrØnniche; SØrensen, Jens Christian

2013-01-01

117

Protein microgels from amyloid fibril networks.  

Science.gov (United States)

Nanofibrillar forms of proteins were initially recognized in the context of pathology, but more recently have been discovered in a range of functional roles in nature, including as active catalytic scaffolds and bacterial coatings. Here we show that protein nanofibrils can be used to form the basis of monodisperse microgels and gel shells composed of naturally occurring proteins. We explore the potential of these protein microgels to act as drug carrier agents, and demonstrate the controlled release of four different encapsulated drug-like small molecules, as well as the component proteins themselves. Furthermore, we show that protein nanofibril self-assembly can continue after the initial formation of the microgel particles, and that this process results in active materials with network densities that can be modulated in situ. We demonstrate that these materials are nontoxic to human cells and that they can be used to enhance the efficacy of antibiotics relative to delivery in homogeneous solution. Because of the biocompatibility and biodegradability of natural proteins used in the fabrication of the microgels, as well as their ability to control the release of small molecules and biopolymers, protein nanofibril microgels represent a promising class of functional artificial multiscale materials generated from natural building blocks. PMID:25469621

Shimanovich, Ulyana; Efimov, Igor; Mason, Thomas O; Flagmeier, Patrick; Buell, Alexander K; Gedanken, Aharon; Linse, Sara; Åkerfeldt, Karin S; Dobson, Christopher M; Weitz, David A; Knowles, Tuomas P J

2015-01-27

118

The serum amyloid A response to sterile silver nitrate in mice and its inhibition by dexamethasone and macrolide antibiotics.  

Science.gov (United States)

Serum amyloid A protein (SAA) is an acute phase protein, known to be a sensitive indicator of inflammation. We have characterized the time course of the SAA response and inflammatory reaction to silver nitrate injection s.c. in mice and studied the effects of dexamethasone and macrolide antibiotics. 2% Sterile silver nitrate solution was injected s.c. into female BALB/c mice and blood collected by capillary action from the tail vein of each mouse at different time points. Hematological variables were determined, albumin by spectrophotometry and SAA and cytokines by ELISA. Animals were treated with either a single i.p. dose of dexamethasone (5-30 mg/kg) 1 h after or daily oral doses of macrolide antibiotics for 3 days. SAA concentrations after silver nitrate injection peaked at 24 h, preceded by increases in serum IL-1 beta and IL-6, associated with decreases in blood leukocytes and local tissue inflammation. Single dexamethasone treatment and daily dosing for 3 days with azithromycin, clarithromycin and roxithromycin (20-80 mg/kg p.o.), but not erythromycin (100-150 mg/kg p.o.), inhibited the increase in SAA but with varying time courses. SAA, measured continuously, is a useful marker of sterile inflammation in mice and is differentially inhibited by macrolide antibiotics. PMID:17920531

Glojnaric, Ines; Cuzic, Snjezana; Erakovic-Haber, Vesna; Parnham, Michael J

2007-12-01

119

Serum amyloid A as an indicator of health status in falcons.  

Science.gov (United States)

Serum amyloid A (SAA) is used as an indicator of health status in many species. To investigate the possible use of SAA as a health indicator in falcons, SAA levels were measured in 259 falcons of varying species and health status. A significant increase (P < .001) in SAA concentrations was observed in falcons affected by inflammatory disease compared with healthy birds and birds with noninflammatory disease. Serum amyloid A concentrations ranged from 0.1 to 6.8 mg/L (mean [SD], 3.4 +/- 1.4 mg/L) in the healthy group, from 0.8 to 8.5 mg/L (mean [SD], 4.0 +/- 3.1 mg/L) in the group with noninflammatory disease, and from 2.3 to 137.5 mg/L (mean [SD], 47.7 +/- 29.7 mg/L) in the group with inflammatory disease. In birds with chronic pododermatitis or fungal pneumonia/airsacculitis, SAA levels remained significantly increased throughout the study period. These results indicate that SAA concentrations can be used in avian medicine to assess the health status of falcons and as a prognostic indicator of certain pathologic disease processes. PMID:23971216

Caliendo, Valentina; McKinney, Peter; Bailey, Tom; Kinne, Joerg; Wernery, Ulrich

2013-06-01

120

Evaluation of Infective Property of Recombinant Prion Protein Amyloids in Cultured Cells Overexpressing Cellular Prion Protein  

OpenAIRE

Misfolded isoform of prion protein (PrP), termed scrapie PrP (PrPSc), tends to aggregate into various fibril forms. Previously, we reported various conditions that affect aggregation of recombinant PrP into amyloids. Because amyloidogenesis of PrP is closely associated with transmissible spongiform encephalopathies such as Creutzfeldt-Jakob disease in humans, we investigated infectivity of recombinant PrP amyloids generated in vitro. Using cultured cell lines which overexpress cellular PrP of...

Kim, Dae-hwan; Lee, Hye-mi; Ryou, Chongsuk

2014-01-01

121

Validación analítica de técnicas comerciales para la determinación de haptoglobina, proteína C reactiva y amiloide A sérico en caninos Analytical / validation of commercial assays for the determination of haptoglobin, C-reactive protein and serum amyloid A in dogs  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Los métodos analíticos deben ser validados antes de emplearlos de forma rutinaria en un laboratorio. El objetivo de este trabajo fue validar tres métodos analíticos comerciales usados en nuestro laboratorio para la determinación de haptoglobina (Hp), proteína C reactiva (CRP) y amiloide A sérico (SA [...] A) en muestras de la especie canina con concentraciones bajas y altas de proteínas de fase aguda (PFAs). Los parámetros que se evaluaron para la validación fueron: (1) Precisión, determinada mediante el cálculo de los coeficientes de variación (CVs) intra e interdeterminación. (2) Exactitud, evaluada indirectamente comprobando la linealidad bajo dilución. (3) Límite de detección, determinado como la mínima concentración que puede distinguirse de una muestra de valor 0. Todos los CVs intradeterminación fueron Abstract in english All laboratory tests must be validated before being introduced for patient testing. The objective of this work was to perform the analytical validation of three commercial assays that are being used at our laboratory for the determination of haptoglobin (Hp), C reactive protein (CRP) and serum amylo [...] id A (SAA) in canine samples with low and high concentrations of these acute phase proteins (APPs). The parameters evaluated for the validation of the methods were: (1) Precision, assessed by determination of the within and between-run coefficients of variation (CVs). (2) Inaccuracy, evaluated indirectly by investigating linearity under dilution. (3) Limit of detection, determined as the lowest concentration of the APPs which could be distinguished from a zero sample. All within-run CVs were lower than 10%, however between-run CVs were lower than 10% only for Hp. Dilution of a serum sample with high concentrations of the different APPs resulted in a linear regression equation with correlation coefficient R²0.98 in all cases; so all methods showed a good accuracy. The detection limit of each assay was 0.02 g/L for Hp, 0.15 mg/L for CRP and 0.79 mg/L for SAA. Additionally they differentiate animals with inflammatory or infectious diseases from healthy subjects. Overall results of validation showed that the assays tested can be suitable for the routine measurement of APPs in canine samples, although it would be desirable to reduce the between run imprecision found for CRP and SAA assays.

S., Martínez-Subiela; J. J., Cerón.

122

Immunohistochemical investigation of amyloid ß-protein (Aß) in the brain of aged cats  

OpenAIRE

To clarify the immunohistochemical features of amyloid deposits and cerebral amyloid angiopathy (CAA), the distribution of the amyloid ß-protein subtypes Aß40, Aß42, Aß43 and Aß precursor protein (APP) were examined in the brains of fourteen aged cats (7.5-21 year-old). Two types of plaques were detected. The first type was characterized by Aß positive antigenic material and detected in the cortical layers of the frontal and parietal lobes of all examined...

Brellou, G.; Vlemmas, I.; Lekkas, S.; Papaioannou, N.

2005-01-01

123

In vitro Generation of Amyloid A4 Peptide from Amyloid Protein Precursor Through Nonspecific Proteolysis  

Directory of Open Access Journals (Sweden)

Full Text Available Amyloid A4 peptide, the principal constituents of the senile plaques in Alzheimer`s disease (AD originates from proteolysis of a larger protein precursor (APP. Several lines of evidence suggest that this peptide may be generated from aggregated precursor through nonspecific proteolysis. In this work, we used a sensitive in vitro method of detection to investigate the role of nonspecific proteases in the processing of a 100-amino acid C-terminal fragment (C100 inclusive of A4 and cytoplasmic domain of APP. We demonstrate first that C100 forms high molecular weight aggregates in vitro as determined by size exclusion chromatography. Digestion of aggregated C100 with the nonspecific enzyme, proteinase K resulted in cleavage at the amyloidogenic -secretase sites. This occurred at Ala 42-Val 43 generating A4 12-42 & A4 16-42 amyloid peptides. The enzyme cleaved most of the peptide bonds of the cytoplasmic domain and the upstream of A4 domain of the substrate. The result suggests that both the N- and C-terminus A4 can be generated by nonspecific proteases, acting on a aggregated substrate and support the notion that the A4 can be formed in organelles containing proteases capable of cleaving most peptide bonds.

Golam Sadik

2001-01-01

124

Interleukin-1 stimulates the beta-amyloid precursor protein promoter.  

Science.gov (United States)

1. Amyloid plaques found in the brains of Alzheimer's diseased patients are composed of the 42 amino acid beta-amyloid peptide (BAP) which is processed out of the larger amyloid precursor protein (APP). 2. To study the regulation of the APP gene expression, we have isolated the promoter region of this angle of this single-copy gene and produced a reporter gene system to determine if the promoter is responsive to agents that may cause the overproduction of APP leading to the abnormal accumulation of plaques in AD. 3. The promoter contains sequences homologous to heat shock elements, AP-1 binding sites, and phorbol ester-inducible sequences as well as GG-rich regions found in other constitutively expressed genes. 4. We show here that this promoter is inducible in cultured cells by interleukin-1 (IL-1) in a transient assay system and that the HSE and AP-1 binding site are required for this inducibility. 5. This induction of transcription from the APP promoter implies that this gene is responsive to tropic and/or trophic agents which may be present in the diseased brain. PMID:2091832

Donnelly, R J; Friedhoff, A J; Beer, B; Blume, A J; Vitek, M P

1990-12-01

125

Scintigraphic imaging and turnover studies with iodine-131 labelled serum amyloid P component in systemic amyloidosis  

Energy Technology Data Exchange (ETDEWEB)

Radiolabelled serum amyloid P component (SAP) is a specific tracer for amyloid. Iodine-123 has ideal physical characteristics for scintigraphy but is expensive and not widely available. Here we report serial imaging and turnover studies in which we labelled SAP with iodine-131, a cheap alternative isotope which would be expected to yield poorer images but permit more prolonged turnover measurements. Imaging and plasma clearance and whole body retention (WBR) of tracer were studied for up to 7 days in ten patients with proven systemic AL amyloidosis and two patients in whom the diagnosis was suspected, after i.v. administration of about 37 MBq of {sup 131}I-SAP. Normal blood pool images were obtained in the latter two subjects and amyloidosis was subsequently refuted histologically. WBR at 48 h was <60% and 6-h plasma activity was >65% of the injected dose (i.d.). Among the other ten patients, amyloid deposits were identified in the spleen in eight cases, liver in five and kidneys in four; other sites that gave positive results included bone, joints and soft tissues, and the myocardium in one case. Up to 95% of the tracer localised into amyloid within 6-h, and the values for WBR became progressively more discriminating during the study period, exceeding the normal reference value (<25%) in all cases by day 7. The optimal imaging time was found to be between 24 and 48 h. The duration of the study enabled us to measure the tracer elimination half-life which was increased in all cases by up to tenfold. Follow-up studies performed after 2-24 months in four patients who were treated with iododoxorubicin showed regression of amyloid in one patient and a small increase in one case; in the other two patients the imaging and turnover studies were identical to baseline. Despite its unfavourable imaging characteristics, {sup 131}I-SAP produced diagnostic scans in every patient in this series and, coupled with the detailed turnover information, is adequate for monitoring disease progress. (orig.) With 5 figs., 2 tabs., 19 refs.

Hawkins, P.N.; Pepys, M.B. [Immunological Medicine Unit, Department of Medicine, Royal Postgraduate Medical School, London (United Kingdom); Aprile, C. [Nuclear Medicine Service, Scientific Institute Fondazione Maugeri, Pavia (Italy); Capri, G.; Vigano, L.; Munzone, E.; Gianni, L. [Division of Medical Oncology, Istituto Nazionale Tumori, Milan (Italy); Merlini, G. [Biotechnology Research Laboratories, University Hospital S. Matteo, Pavia (Italy)

1998-07-01

126

Serum Protein Profile Alterations in Hemodialysis Patients  

Energy Technology Data Exchange (ETDEWEB)

Background: Serum protein profiling patterns can reflect the pathological state of a patient and therefore may be useful for clinical diagnostics. Here, we present results from a pilot study of proteomic expression patterns in hemodialysis patients designed to evaluate the range of serum proteomic alterations in this population. Methods: Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOFMS) was used to analyze serum obtained from patients on periodic hemodialysis treatment and healthy controls. Serum samples from patients and controls were first fractionated into six eluants on a strong anion exchange column, followed by application to four array chemistries representing cation exchange, anion exchange, metal affinity and hydrophobic surfaces. A total of 144 SELDI-TOF-MS spectra were obtained from each serum sample. Results: The overall profiles of the patient and control samples were consistent and reproducible. However, 30 well-defined protein differences were observed; 15 proteins were elevated and 15 were decreased in patients compared to controls. Serum from one patient exhibited novel protein peaks suggesting possible additional changes due to a secondary disease process. Conclusion: SELDI-TOF-MS demonstrated dramatic serum protein profile differences between patients and controls. Similarity in protein profiles among dialysis patients suggests that patient physiological responses to end-stage renal disease and/or dialysis therapy have a major effect on serum protein profiles.

Murphy, G A; Davies, R W; Choi, M W; Perkins, J; Turteltaub, K W; McCutchen-Maloney, S L; Langlois, R G; Curzi, M P; Trebes, J E; Fitch, J P; Dalmasso, E A; Colston, B W; Ying, Y; Chromy, B A

2003-11-18

127

Soluble Prion Protein Inhibits Amyloid-? (A?) Fibrillization and Toxicity*  

Science.gov (United States)

The pathogenesis of Alzheimer disease appears to be strongly linked to the aggregation of amyloid-? (A?) peptide and, especially, formation of soluble A?1–42 oligomers. It was recently demonstrated that the cellular prion protein, PrPC, binds with high affinity to these oligomers, acting as a putative receptor that mediates at least some of their neurotoxic effects. Here we show that the soluble (i.e. glycophosphatidylinositol anchor-free) prion protein and its N-terminal fragment have a strong effect on the aggregation pathway of A?1–42, inhibiting its assembly into amyloid fibrils. Furthermore, the prion protein prevents formation of spherical oligomers that normally occur during A? fibrillogenesis, acting as a potent inhibitor of A?1–42 toxicity as assessed in experiments with neuronal cell culture. These findings may provide a molecular level foundation to explain the reported protective action of the physiologically released N-terminal N1 fragment of PrPC against A? neurotoxicity. They also suggest a novel approach to pharmacological intervention in Alzheimer disease. PMID:22915585

Nieznanski, Krzysztof; Choi, Jin-Kyu; Chen, Shugui; Surewicz, Krystyna; Surewicz, Witold K.

2012-01-01

128

Soluble prion protein inhibits amyloid-? (A?) fibrillization and toxicity.  

Science.gov (United States)

The pathogenesis of Alzheimer disease appears to be strongly linked to the aggregation of amyloid-? (A?) peptide and, especially, formation of soluble A?1-42 oligomers. It was recently demonstrated that the cellular prion protein, PrP(C), binds with high affinity to these oligomers, acting as a putative receptor that mediates at least some of their neurotoxic effects. Here we show that the soluble (i.e. glycophosphatidylinositol anchor-free) prion protein and its N-terminal fragment have a strong effect on the aggregation pathway of A?1-42, inhibiting its assembly into amyloid fibrils. Furthermore, the prion protein prevents formation of spherical oligomers that normally occur during A? fibrillogenesis, acting as a potent inhibitor of A?1-42 toxicity as assessed in experiments with neuronal cell culture. These findings may provide a molecular level foundation to explain the reported protective action of the physiologically released N-terminal N1 fragment of PrP(C) against A? neurotoxicity. They also suggest a novel approach to pharmacological intervention in Alzheimer disease. PMID:22915585

Nieznanski, Krzysztof; Choi, Jin-Kyu; Chen, Shugui; Surewicz, Krystyna; Surewicz, Witold K

2012-09-28

129

Extracellular matrix-anchored serum amyloid A preferentially induces mast cell adhesion.  

Science.gov (United States)

Mast cells are known to accumulate in various inflammatory processes, some of which are known to be associated with increased local and systemic levels of acute-phase reactants such as serum amyloid A (SAA) or with amyloid deposition. The mechanism(s) by which mast cells are recruited to these sites, however, has not been fully elucidated. It has recently been shown that SAA interacts with extracellular matrix (ECM) components and thereby acts as a chemoattractant and regulator of immune cell migration. On the basis of these observations, we examined the effect of SAA on mast cell adhesion to ECM, an essential step in cellular transmigration. We could first demonstrate strong specific binding of recombinant human SAA (rSAA) to murine mast cells using flow cytometry. Moreover, radiolabeled rSAA was found to bind, in a saturable manner, to mast cells, reaching a binding affinity of 10(-8) M. When immobilized by preincubation with ECM, SAA or its proteolytically degraded amyloid A fragment (amino acid residues 2-82), which contains RGD-related adhesion motif but not the COOH-terminal portion of SAA (amino acid residues 77-104), induced the adhesion of resting mast cells to ECM or laminin. SAA and AA, in soluble or immobilized forms, did not activate mast cells to release mediators. Mast cell adhesion to the immobilized ECM-SAA complex appeared to occur through an integrin recognition, inasmuch as adhesion was calcium dependent and could be blocked by an RGD-containing peptide or by anti-CD29 monoclonal antibody. Genistein also inhibited adhesion, indicating that tyrosine kinase activity was involved. These data suggest that SAA bound to ECM may serve as an important inducer of mast cell adhesion, thus regulating mast cell recruitment and accumulation at these sites, which in turn could potentiate further pathology. PMID:9252455

Hershkoviz, R; Preciado-Patt, L; Lider, O; Fridkin, M; Dastych, J; Metcalfe, D D; Mekori, Y A

1997-07-01

130

Endogenous Acute Phase Serum Amyloid A Lacks Pro-Inflammatory Activity, Contrasting the Two Recombinant Variants That Activate Human Neutrophils through Different Receptors  

OpenAIRE

Most notable among the acute phase proteins is serum amyloid A (SAA), levels of which can increase 1000-fold during infections, aseptic inflammation, and/or trauma. Chronically elevated SAA levels are associated with a wide variety of pathological conditions, including obesity and rheumatic diseases. Using a recombinant hybrid of the two human SAA isoforms (SAA1 and 2) that does not exist in vivo, numerous in vitro studies have given rise to the notion that acute phase SAA is a pro-inflammato...

Christenson, Karin; Bjo?rkman, Lena; Ahlin, Sofie; Olsson, Maja; Sjo?holm, Kajsa; Karlsson, Anna; Bylund, Johan

2013-01-01

131

Structural and Dynamic Study of the Transmembrane Domain of the Amyloid Precursor Protein  

OpenAIRE

Alzheimer’s disease affects people all over the world, regardless of nationality, gender or social status. An adequate study of the disease requires essential understanding of the molecular fundamentals of the pathogenesis. The amyloid ?-peptide, which forms amyloid plaques in the brain of people with Alzheimer’s disease, is the product of sequential cleavage of a single-span membrane amyloid precursor protein (APP). More than half of the APP mutations found to be associated with familia...

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

2011-01-01

132

Histological regression of amyloid in AL amyloidosis is exclusively seen after normalization of serum free light chain  

OpenAIRE

Amyloidosis is thought to be a dynamic process of deposition and resolution. This implies that after elimination of the precursor protein, amyloid deposits in organs might resolve in the course of time resulting in improvement of both organ function and clinical performance. The findings of this study indicate that achievement of complete response of amyloidogenic free light chain following chemotherapy is associated with a significant reduction in amyloid deposition in fat tissue. See relate...

Gameren, Ingrid I.; Rijswijk, Martin H.; Bijzet, Johan; Vellenga, Edo; Hazenberg, Bouke P.

2009-01-01

133

beta -Amyloid peptide-induced apoptosis regulated by a novel protein containing a g protein activation module.  

Science.gov (United States)

Degeneration of neurons in Alzheimer's disease is mediated by beta-amyloid peptide by diverse mechanisms, which include a putative apoptotic component stimulated by unidentified signaling events. This report describes a novel beta-amyloid peptide-binding protein (denoted BBP) containing a G protein-coupling module. BBP is one member of a family of three proteins containing this conserved structure. The BBP subtype bound human beta-amyloid peptide in vitro with high affinity and specificity. Expression of BBP in cell culture induced caspase-dependent vulnerability to beta-amyloid peptide toxicity. Expression of a signaling-deficient dominant negative BBP mutant suppressed sensitivity of human Ntera-2 neurons to beta-amyloid peptide mediated toxicity. These findings suggest that BBP is a target of neurotoxic beta-amyloid peptide and provide new insight into the molecular pathophysiology of Alzheimer's disease. PMID:11278849

Kajkowski, E M; Lo, C F; Ning, X; Walker, S; Sofia, H J; Wang, W; Edris, W; Chanda, P; Wagner, E; Vile, S; Ryan, K; McHendry-Rinde, B; Smith, S C; Wood, A; Rhodes, K J; Kennedy, J D; Bard, J; Jacobsen, J S; Ozenberger, B A

2001-06-01

134

The amyloid precursor protein and postnatal neurogenesis/neuroregeneration  

International Nuclear Information System (INIS)

The amyloid precursor protein (APP) is the source of amyloid-beta (A?) peptide, produced via its sequential cleavage ?- and ?-secretases. Various biophysical forms of A? (and the mutations of APP which results in their elevated levels) have been implicated in the etiology and early onset of Alzheimer's disease. APP's evolutionary conservation and the existence of APP-like isoforms (APLP1 and APLP2) which lack the A? sequence, however, suggest that these might have important physiological functions that are unrelated to A? production. Soluble N-terminal fragments of APP have been known to be neuroprotective, and the interaction of its cytoplasmic C-terminus with a myriad of proteins associates it with diverse processes such as axonal transport and transcriptional regulation. The notion for an essential postnatal function of APP has been demonstrated genetically, as mice deficient in both APP and APLP2 or all three APP isoforms exhibit early postnatal lethality and neuroanatomical abnormalities. Recent findings have also brought to light two possible functions of the APP family in Brain-regulation of neural progenitor cell proliferation and axonal outgrowth after injury. Interestingly, these two apparently related neurogenic/neuroregenerative functions of APP involve two separate domains of the molecule

135

A Drosophila gene encoding a protein resembling the human ?-amyloid protein precursor  

International Nuclear Information System (INIS)

The authors have isolated genomic and cDNA clones for a Drosophila gene resembling the human ?-amyloid precursor protein (APP). This gene produces a nervous system-enriched 6.5-kilobase transcript. Sequencing of cDNAs derived from the 6.5-kilobase transcript predicts an 886-amino acid polypeptide. This polypeptide contains a putative transmembrane domain and exhibits strong sequence similarity to cytoplasmic and extracellular regions of the human ?-amyloid precursor protein. There is a high probability that this Drosophila gene corresponds to the essential Drosophila locus vnd, a gene required for embryonic nervous system development

136

Amyloid-clearing proteins and their epigenetic regulation as a therapeutic target in Alzheimer’s disease  

OpenAIRE

Abnormal elevation of amyloid ?-peptide (A?) levels in the brain is the primary trigger for neuronal cell death specific to Alzheimer’s disease (AD). It is now evident that A? levels in the brain are manipulable due to a dynamic equilibrium between its production from the amyloid precursor protein (APP) and removal by amyloid clearance proteins. Clearance can be either enzymic or non-enzymic (binding/transport proteins). Intriguingly several of the main amyloid-degrading enzymes (ADEs) a...

Turner, Anthony J.; Nalivaeva, Natalia N.; Caroline Kerridge

2014-01-01

137

Comparison of paired serum and lithium heparin plasma samples for the measurement of serum amyloid A in horses using an automated turbidimetric immunoassay.  

Science.gov (United States)

This study aimed to evaluate whether equine serum amyloid A (SAA) concentrations could be reliably measured in plasma with a turbidimetric immunoassay previously validated for equine SAA concentrations in serum. Paired serum and lithium-heparin samples obtained from 40 horses were evaluated. No difference was found in SAA concentrations between serum and plasma using a paired t test (P=0.48). The correlation between paired samples was 0.97 (Spearman's rank Pregression analyses revealed no differences between paired samples. Bland-Altman plots revealed a positive bias in plasma compared to serum but the difference was not considered clinically significant. The results indicate that lithium-heparin plasma samples are suitable for measurement of equine SAA using this method. Use of either serum or plasma allows for greater flexibility when it comes to sample collection although care should be taken when comparing data between measurements from different sample types. PMID:24412695

Howard, Judith; Graubner, Claudia

2014-03-01

138

Cross-Seeding and Cross-Competition in Mouse Apolipoprotein A-II Amyloid Fibrils and Protein A Amyloid Fibrils  

OpenAIRE

Murine senile [apolipoprotein A-II amyloid (AApoAII)] and reactive [protein A amyloid (AA)] amyloidosis are reported to be transmissible diseases via a seeding mechanism similar to that observed in the prion-associated disorders, although de novo amyloidogenesis and the progression of AApoAII or AA amyloidosis remain unclear. We examined the effect of co-injection of AApoAII and AA fibrils and multiple inflammatory stimuli in R1.P1-Apoa2c mice with the amyloidogenic Apoa2c allele. Both AApoAI...

Yan, Jingmin; Fu, Xiaoying; Ge, Fengxia; Zhang, Beiru; Yao, Junjie; Zhang, Huanyu; Qian, Jinze; Tomozawa, Hiroshi; Naiki, Hironobu; Sawashita, Jinko; Mori, Masayuki; Higuchi, Keiichi

2007-01-01

139

Antibody-bound amyloid precursor protein upregulates ornithine decarboxylase expression  

DEFF Research Database (Denmark)

Alzheimer's disease is a neurodegenerative disorder characterised by extracellular accumulation of the Abeta peptide, derived from the amyloid precursor protein (APP). The function of APP as a cell surface receptor was examined by ligand-mimicking using an antibody against the APP extracellular domain. Alterations in gene expression evoked by antibody-bound APP were analysed using human pathway-finder gene arrays and the largest change in expression levels was found for ornithine decarboxylase (ODC). These results were confirmed by Western blotting which showed even higher upregulation on the protein level. APP knockdown by RNAi verified that upregulation of ODC was APP-mediated. This APP signalling event did not require gamma-secretase cleavage, as it was independent of the presence of presenilin-1 or -2. The induced ODC expression was rapid and biphasic, resembling growth-factor stimulated signalling events. This study shows that antibody-bound APP leads to altered gene expression that may be relevant to AD.

Nilsson, Tatjana; Malkiewicz, Katarzyna

2006-01-01

140

Increased serum amyloid A and its association with autoantibodies, acute phase reactants and disease activity in patients with rheumatoid arthritis.  

Science.gov (United States)

Determination of disease activity in patients with rheumatoid arthritis (RA) has become an important component for RA management. The aim of the present study was to investigate the association between circulating levels of serum amyloid A (SAA) and disease activity in RA patients. The types of disease and the respective number of patients enrolled in the present study were as follows: RA, 88; osteoarthritis (OA), 54; systemic lupus erythematosus (SLE), 43; and other autoimmune diseases, 30, as well as 50 healthy controls (HC). SAA levels were measured using an ELISA assay and western blot analysis was used to detect serum SAA levels. The correlations between SAA levels and disease activity score for 28 joints (DAS28), erythrocyte sedimentation rate (ESR) and C?reactive protein (CRP), respectively, were evaluated; in addition, the presence and absence of rheumatoid factor (RF) and anti?cyclic citrullinated peptide antibody (anti?CCP) were detected in respect to SAA levels. The results of the present study demonstrated that serum levels of SAA in RA patients were significantly increased compared to those of the OA, SLE, others and HC patients (P<0.05). SAA levels were found to be positively correlated with DAS28, ESR and CRP levels (R2=0.6174, 0.4422 and 0.3919, respectively). In addition, anti?CCP was not correlated with DAS28 (R2=0.0154). Furthermore, increased SAA levels were detected in patients with positive anti?CCP compared with those in anti?CCP negative subjects (P<0.01). In conclusion, the results of the present study provided further evidence for possible roles of SAA in RA, which indicated that it may be a useful biomarker for assessing disease severity and may provide additional information about disease activity. PMID:25352049

Shen, Chen; Sun, Xu-Guo; Liu, Na; Mu, Yun; Hong, Cheng-Cheng; Wei, Wei; Zheng, Fang

2015-02-01

141

Interleukin 6, serum amyloid A and haptoglobin as markers of treatment efficacy in pigs experimentally infected with Actinobacillus pleuropneumoniae.  

Science.gov (United States)

The possibility to use acute phase proteins to monitor the elimination of a bacterial infection in pigs would facilitate an objective assessment of treatment with various antimicrobial substances. To examine this possibility, the acute phase response (IL-6, serum amyloid A (SAA), and haptoglobin) elicited by Actinobacillus pleuropneumoniae and its reduction on treatment with various antibiotics was studied in serum from specific pathogen free (SPF) pigs. Pigs were infected intranasally with A. pleuropneumoniae serotype 2, and either left as non-treated control pigs or treated with different antibiotics intramuscularly at onset of respiratory disease (20h post-infection). Pigs responded to the infection with prominent increases in activity and concentrations of IL-6, SAA, and haptoglobin. These responses were to a certain extent overlapping and covered the time span from a few hours after infection until development of detectable levels of specific antibodies (7-10 days post-infection in untreated pigs). The haptoglobin response lasted until the end of the study on day 17 and thereby partly coincided with the antibody response. Treatment with antimicrobials that effectively reduced establishment of the infection with A. pleuropneumoniae also reduced the duration of all three acute phase responses, and reduced the concentration of serum haptoglobin. In contrast, less efficacious treatments did not reduce these acute phase responses. Thus, acute phase reactants can be applied to monitor therapeutic effects of antimicrobial drugs in the pig and measurements of IL-6, SAA and haptoglobin could add valuable information about the stage of infection during a disease outbreak. PMID:12860078

Hultén, C; Johansson, E; Fossum, C; Wallgren, P

2003-08-29

142

Serum amyloid a gene expression and immunohistochemical localization in rainbow trout, Oncorhynchus mykiss, infected by Yersinia ruckeri  

DEFF Research Database (Denmark)

Serum amyloid A (SAA) is an integral part of the innate immune response in general and in particular the acute phase response. SAA belongs to a highly conserved group of apolipoproteins reported from different groups of organisms such as mammals, birds, fish and even invertebrates. The present study was undertaken to elucidate the role of SAA protein in the innate immune response of rainbow trout. For this purpose a monoclonal antibody was raised against a recombinant peptide of rainbow trout SAA. The antibody was characterized using Western blot, immunohistochemistry and ELISA techniques. SAA was found to be associated with high density lipoprotein (HDL) which complicated band identification in Western blot, but delipidization of the SAA-HDL isolate, using a solvent extraction method, highly increased the quality of reaction in the Western blot. Inhibition ELISA indicated the presence of SAA in serum and tissues (head kidney, liver and spleen) of rainbow trout. Rainbow trout fry (87 days post hatch) infected with Yersinia ruckeri showed a significant up-regulation of the SAA gene at 72 h post infection with further increase at 96 h post infection. Non-significant up-regulations were seen at earlier time points i.e. 4 and 24 h. A weak staining with the monoclonal antibody was seen at 4 h post infection which increased in intensity during the course of infection i.e. 24, 72 and 96 h post infection. The expression pattern of SAA in the infected fry, analysed by qPCR, significantly correlated with the results obtained by immunohistochemical methods. From the present study it can be concluded that the SAA may act as an acute phase protein in rainbow trout and its expression increases significantly during the course of infection.

Kania, Per Walter; Buchmann, Kurt

143

Serum protein-binding characteristics of vancomycin.  

OpenAIRE

A synthesis of studies of serum protein binding of vancomycin and its reported abnormal binding in serum with very high concentrations of immunoglobulin A (IgA) suggests that this antibiotic may be bound to more than one serum protein. Using an ultrafiltration method for separating free from bound drug and high-performance liquid chromatography to measure drug concentration, we studied the binding characteristics of vancomycin for alpha-1 acid glycoprotein, IgG, IgM, IgA, and albumin. The res...

Sun, H.; Maderazo, E. G.; Krusell, A. R.

1993-01-01

144

Amyloid fibril protein in familial amyloidotic polyneuropathy, Portuguese type. Definition of molecular abnormality in transthyretin (prealbumin).  

OpenAIRE

Amyloid fibril protein in patients with familial amyloidotic polyneuropathy is known to be chemically related to transthyretin (TTR), the plasma protein that is usually referred to as prealbumin. A genetically abnormal TTR may be involved in this disease. Studies were conducted on amyloid fibril protein (AFp) isolated from tissues of two Portuguese patients who died with familial amyloidosis, and on TTR isolated from sera of patients with this disease. AFp, purified by affinity chromatography...

Saraiva, M. J.; Birken, S.; Costa, P. P.; Goodman, D. S.

1984-01-01

145

Curcumin Reduces Amyloid Fibrillation of Prion Protein and Decreases Reactive Oxidative Stress  

OpenAIRE

Misfolding and aggregation into amyloids of the prion protein (PrP) is responsible for the development of fatal transmissible neurodegenerative diseases. Various studies on curcumin demonstrate promise for the prevention of Alzheimer’s disease and inhibition of PrPres accumulation. To evaluate the effect of curcumin on amyloid fibrillation of prion protein, we first investigated the effect of curcumin on mouse prion protein (mPrP) in a cell-free system. Curcumin reduced the prion fibril for...

Raymond Chung; Cheng-I Lee; Chi-Fen Lin; Cheng-Ping Jheng; Kun-Hua Yu

2013-01-01

146

Serum amyloid A-derived peptides, present in human rheumatic synovial fluids, induce the secretion of interferon-gamma by human CD(4)(+) T-lymphocytes.  

Science.gov (United States)

Serum amyloid A (SAA) is a major acute-phase protein whose biochemical functions remain largely obscure. Human rheumatic synovial fluids were screened by high performance liquid chromatography mass spectrometry for SAA-derived peptides, specifically the sequence AGLPEKY (SAA(98-104)) which was previously shown to modulate various leukocyte functions. Two such fluids were found to contain a truncated version of SAA(98-104). Synthetic SAA(98-104) and several of its analogs were shown capable of binding isolated human CD(4)(+) T-lymphocytes and stimulating them to produce interferon-gamma. Given the high acute-phase serum level of SAA and its massive proteolysis by inflammatory related enzymes, SAA-derived peptides may be involved in host defense mechanisms. PMID:10788622

Yavin, E J; Preciado-Patt, L; Rosen, O; Yaron, M; Suessmuth, R D; Levartowsky, D; Jung, G; Lider, O; Fridkin, M

2000-04-28

147

Protein amyloids develop an intrinsic fluorescence signature during aggregation.  

Science.gov (United States)

We report observations of an intrinsic fluorescence in the visible range, which develops during the aggregation of a range of polypeptides, including the disease-related human peptides amyloid-?(1-40) and (1-42), lysozyme and tau. Characteristic fluorescence properties such as the emission lifetime and spectra were determined experimentally. This intrinsic fluorescence is independent of the presence of aromatic side-chain residues within the polypeptide structure. Rather, it appears to result from electronic levels that become available when the polypeptide chain folds into a cross-? sheet scaffold similar to what has been reported to take place in crystals. We use these findings to quantify protein aggregation in vitro by fluorescence imaging in a label-free manner. PMID:23420088

Chan, Fiona T S; Kaminski Schierle, Gabriele S; Kumita, Janet R; Bertoncini, Carlos W; Dobson, Christopher M; Kaminski, Clemens F

2013-04-01

148

Driving force of binding of amyloid ?-protein to lipid bilayers  

International Nuclear Information System (INIS)

Amyloid ?-protein (A?) has been reported to interact with a variety of lipid species, although the thermodynamic driving force remains unclear. We investigated the binding of A?s labeled with the dye diethylaminocoumarin (DAC-A?s) to lipid bilayers under various conditions. DAC-A?-(1-40) electrostatically bound to anionic and cationic lipids at acidic and alkaline interfacial pH, respectively. However, at neutral pH, electroneutral A? did not bind to these lipids, indicating little hydrophobic interaction between A?-(1-40) and the acyl chains of lipids. In contrast, DAC-A? associated with glycolipids even under electroneutral conditions. These results suggested that hydrogen-bonding as well as hydrophobic interactions with sugar groups of glycolipids drive the membrane binding of A?-(1-40)

149

Adenosine triphosphate (ATP) reduces amyloid-? protein misfolding in vitro.  

Science.gov (United States)

Alzheimer's disease (AD) is a devastating disease of aging that initiates decades prior to clinical manifestation and represents an impending epidemic. Two early features of AD are metabolic dysfunction and changes in amyloid-? protein (A?) levels. Since levels of ATP decrease over the course of the disease and A? is an early biomarker of AD, we sought to uncover novel linkages between the two. First and remarkably, a GxxxG motif is common between both A? (oligomerization motif) and nucleotide binding proteins (Rossmann fold). Second, ATP was demonstrated to protect against A? mediated cytotoxicity. Last, there is structural similarity between ATP and amyloid binding/inhibitory compounds such as ThioT, melatonin, and indoles. Thus, we investigated whether ATP alters misfolding of the pathologically relevant A?42. To test this hypothesis, we performed computational and biochemical studies. Our computational studies demonstrate that ATP interacts strongly with Tyr10 and Ser26 of A? fibrils in solution. Experimentally, both ATP and ADP reduced A? misfolding at physiological intracellular concentrations, with thresholds at ~500 ?M and 1 mM respectively. This inhibition of A? misfolding is specific; requiring Tyr10 of A? and is enhanced by magnesium. Last, cerebrospinal fluid ATP levels are in the nanomolar range and decreased with AD pathology. This initial and novel finding regarding the ATP interaction with A? and reduction of A? misfolding has potential significance to the AD field. It provides an underlying mechanism for published links between metabolic dysfunction and AD. It also suggests a potential role of ATP in AD pathology, as the occurrence of misfolded extracellular A? mirrors lowered extracellular ATP levels. Last, the findings suggest that A? conformation change may be a sensor of metabolic dysfunction. PMID:24625803

Coskuner, Orkid; Murray, Ian V J

2014-01-01

150

Amyloid fibrils from readily available sources: milk casein and lens crystallin proteins.  

Science.gov (United States)

Amyloid fibrils are a highly ordered and robust aggregated form of protein structure in which the protein components are arranged in long fibrillar arrays comprised of ?-sheet. Because of these properties, along with their biocompatibility, amyloid fibrils have attracted much research attention as bionanomaterials, for example as template structures (in some cases following modification) that can be used as biosensors, encapsulators, and biomimetic materials. To use amyloid fibrils for such a range of applications will require them to be obtained relatively easily in large quantities. In this chapter, we describe methods for isolating crystallin and casein proteins from readily available sources that contain abundant protein, i.e., the eye lens and milk, respectively, and the subsequent conversion of these proteins into amyloid fibrils. PMID:23504420

Ecroyd, Heath; Garvey, Megan; Thorn, David C; Gerrard, Juliet A; Carver, John A

2013-01-01

151

Serum amyloid P component binds to influenza A virus haemagglutinin and inhibits the virus infection in vitro.  

DEFF Research Database (Denmark)

Serum amyloid P component (SAP) is a member of the phylogenetically conserved and structurally related group of proteins called pentraxins. SAP exhibits multispecific calcium-dependent binding to oligosaccharides with terminal N-acetyl-galactosamine, mannose and glucuronic acid. The authors report that SAP can bind to influenza A virus and inhibit agglutination of erythrocytes mediated by the virus subtypes H1N1, H2N2 and H3N2. SAP also inhibits the production of haemagglutinin (HA) an the cytopathogenic effect of influenza A virus in MDCK cells. The binding of SAP to the virus requires physiological calcium concentrations and is blocked by specific SAP antibodies. Denaturated and renaturated SAP retained inhibition of HA. Electron microscopy shows Ca(2+)-dependent binding of SAP to spikes on the viral envelope and immunoblotting indicates that SAP binds to a 50-55 kDa peptide corresponding to the mass of the HA1 peptide. Of several monosaccharides tested only D-mannose interfered with SAP's inhibition of both HA and infectivity. The glycosaminoglycans heparan sulfate and heparin, which bind SAP, reduced SAPs binding to the virus. The results indicate that the inhibition by SAP is due to steric effects when SAP binds to terminal mannose on oligosaccharides localized close to the sialic acid-binding site of the HA trimer.

Andersen, Ove; Vilsgaard Ravn, K

1997-01-01

152

Proteomic evaluation of sheep serum proteins  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The applications of proteomic strategies to ovine medicine remain limited. The definition of serum proteome may be a good tool to identify useful protein biomarkers for recognising sub-clinical conditions and overt disease in sheep. Findings from bovine species are often directly translated for use in ovine medicine. In order to characterize normal protein patterns and improve knowledge of molecular species-specific characteristics, we generated a two-dimensional reference map of sheep serum. The possible application of this approach was tested by analysing serum protein patterns in ewes with mild broncho-pulmonary disease, which is very common in sheep and in the peripartum period which is a stressful time, with a high incidence of infectious and parasitic diseases. Results This study generated the first reference 2-DE maps of sheep serum. Overall, 250 protein spots were analyzed, and 138 identified. Compared with healthy sheep, serum protein profiles of animals with rhino-tracheo-bronchitis showed a significant decrease in protein spots identified as transthyretin, apolipoprotein A1 and a significant increase in spots identified as haptoglobin, endopin 1b and alpha1B glycoprotein. In the peripartum period, haptoglobin, alpha-1-acid glycoprotein, apolipoprotein A1 levels rose, while transthyretin content dropped. Conclusions This study describes applications of proteomics in putative biomarker discovery for early diagnosis as well as for monitoring the physiological and metabolic situations critical for ovine welfare.

Chiaradia Elisabetta

2012-05-01

153

AL Amyloid Imaging and Therapy with a Monoclonal Antibody to a Cryptic Epitope on Amyloid Fibrils  

OpenAIRE

The monoclonal antibody 2A4 binds an epitope derived from a cleavage site of serum amyloid protein A (sAA) containing a -Glu-Asp- amino acid pairing. In addition to its reactivity with sAA amyloid deposits, the antibody was also found to bind amyloid fibrils composed of immunoglobulin light chains. The antibody binds to synthetic fibrils and human light chain (AL) amyloid extracts with high affinity even in the presence of soluble light chain proteins. Immunohistochemistry with biotinylated 2...

Wall, Jonathan S.; Kennel, Stephen J.; Williams, Angela; Richey, Tina; Stuckey, Alan; Huang, Ying; Macy, Sallie; Donnell, Robert; Barbour, Robin; Seubert, Peter; Schenk, Dale

2012-01-01

154

Serum amyloid A opposes lipoxin A4 to mediate glucocorticoid refractory lung inflammation in chronic obstructive pulmonary disease  

OpenAIRE

Chronic obstructive pulmonary disease (COPD) will soon be the third most common cause of death globally. Despite smoking cessation, neutrophilic mucosal inflammation persistently damages the airways and fails to protect from recurrent infections. This maladaptive and excess inflammation is also refractory to glucocorticosteroids (GC). Here, we identify serum amyloid A (SAA) as a candidate mediator of GC refractory inflammation in COPD. Extrahepatic SAA was detected locally in COPD bronchoalve...

Bozinovski, Steven; Uddin, Mohib; Vlahos, Ross; Thompson, Michelle; Mcqualter, Jonathan L.; Merritt, Anne-sophie; Wark, Peter A. B.; Hutchinson, Anastasia; Irving, Louis B.; Levy, Bruce D.; Anderson, Gary P.

2012-01-01

155

Two-protein signature of novel serological markers apolipoprotein-A2 and serum amyloid alpha predicts prognosis in patients with metastatic renal cell cancer and improves the currently used prognostic survival models  

OpenAIRE

Background: In metastatic renal cell cancer (mRCC), the Memorial Sloan-Kettering Cancer Center (MSKCC) risk model is widely used for clinical trial design and patient management. To improve prognostication, we applied proteomics to identify novel serological proteins associated with overall survival (OS). Patients and methods: Sera from 114 mRCC patients were screened by surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF MS). Identified proteins were rela...

Vermaat, J. S.; Tweel, I.; Mehra, N.; Sleijfer, S.; Haanen, J. B.; Roodhart, J. M.; Engwegen, J. Y.; Korse, C. M.; Langenberg, M. H.; Kruit, W. H. J.; Groenewegen, G.; Giles, R. H.

2010-01-01

156

Inhibiting transthyretin amyloid fibril formation via?protein?stabilization  

OpenAIRE

Transthyretin (TTR) amyloid fibril formation is observed systemically in familial amyloid polyneuropathy and senile systemic amyloidosis and appears to be the causative agent in these diseases. Herein, we demonstrate conclusively that thyroxine (10.8 ?M) inhibits TTR fibril formation efficiently in vitro and does so by stabilizing the tetramer against dissociation and the subsequent conformational changes required for amyloid fibril formation. In addition, the non...

Miroy, G. J.; Lai, Z.; Lashuel, H. A.; Peterson, S. A.; Strang, C.; Kelly, J. W.

1996-01-01

157

Organization and biology of the porcine serum amyloid A (SAA) gene cluster: isoform specific responses to bacterial infection.  

Science.gov (United States)

Serum amyloid A (SAA) is a prominent acute phase protein. Although its biological functions are debated, the wide species distribution of highly homologous SAA proteins and their uniform behavior in response to injury or inflammation in itself suggests a significant role for this protein. The pig is increasingly being used as a model for the study of inflammatory reactions, yet only little is known about how specific SAA genes are regulated in the pig during acute phase responses and other responses induced by pro-inflammatory host mediators. We designed SAA gene specific primers and quantified the gene expression of porcine SAA1, SAA2, SAA3, and SAA4 by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in liver, spleen, and lung tissue from pigs experimentally infected with the Gram-negative swine specific bacterium Actinobacillus pleuropneumoniae, as well as from pigs experimentally infected with the Gram-positive bacterium Staphylococcus aureus. Our results show that: 1) SAA1 may be a pseudogene in pigs; 2) we were able to detect two previously uncharacterized SAA transcripts, namely SAA2 and SAA4, of which the SAA2 transcript is primarily induced in the liver during acute infection and presumably contributes to circulating SAA in pigs; 3) Porcine SAA3 transcription is induced both hepatically and extrahepatically during acute infection, and may be correlated to local organ affection; 4) Hepatic transcription of SAA4 is markedly induced in pigs infected with A. pleuropneumoniae, but only weakly in pigs infected with S. aureus. These results for the first time establish the infection response patterns of the four porcine SAA genes which will be of importance for the use of the pig as a model for human inflammatory responses, e.g. within sepsis, cancer, and obesity research. PMID:24146912

Olsen, Helle G; Skovgaard, Kerstin; Nielsen, Ole L; Leifsson, Páll S; Jensen, Henrik E; Iburg, Tine; Heegaard, Peter M H

2013-01-01

158

Serum amyloid A chemoattracts immature dendritic cells and indirectly provokes monocyte chemotaxis by induction of cooperating CC and CXC chemokines.  

Science.gov (United States)

Serum amyloid A (SAA) is an acute phase protein that is upregulated in inflammatory diseases and chemoattracts monocytes, lymphocytes, and granulocytes via its G protein-coupled receptor formyl peptide receptor like 1/formyl peptide receptor 2 (FPRL1/FPR2). Here, we demonstrated that the SAA1? isoform also chemoattracts monocyte-derived immature dendritic cells (DCs) in the Boyden and ?-slide chemotaxis assay and that its chemotactic activity for monocytes and DCs was indirectly mediated via rapid chemokine induction. Indeed, SAA1 induced significant amounts (?5 ng/mL) of macrophage inflammatory protein-1?/CC chemokine ligand 3 (MIP-1?/CCL3) and interleukin-8/CXC chemokine ligand 8 (IL-8/CXCL8) in monocytes and DCs in a dose-dependent manner within 3 h. However, SAA1 also directly activated monocytes and DCs for signaling and chemotaxis without chemokine interference. SAA1-induced monocyte migration was nevertheless significantly prevented (60-80% inhibition) in the constant presence of desensitizing exogenous MIP-1?/CCL3, neutralizing anti-MIP-1?/CCL3 antibody, or a combination of CC chemokine receptor 1 (CCR1) and CCR5 antagonists, indicating that this endogenously produced CC chemokine was indirectly contributing to SAA1-mediated chemotaxis. Further, anti-IL-8/CXCL8 antibody neutralized SAA1-induced monocyte migration, suggesting that endogenous IL-8/CXCL8 acted in concert with MIP-1?/CCL3. This explained why SAA1 failed to synergize with exogenously added MIP-1?/CCL3 or stromal cell-derived factor-1? (SDF-1?)/CXCL12 in monocyte and DC chemotaxis. In addition to direct leukocyte activation, SAA1 induces a chemotactic cascade mediated by expression of cooperating chemokines to prolong leukocyte recruitment to the inflammatory site. PMID:25345597

Gouwy, Mieke; De Buck, Mieke; Pörtner, Noëmie; Opdenakker, Ghislain; Proost, Paul; Struyf, Sofie; Van Damme, Jo

2015-01-01

159

Serum amyloid A generates high density lipoprotein with cellular lipid in an ABCA1- or ABCA7-dependent manner.  

Science.gov (United States)

Serum amyloid A (SAA) is an amphiphilic helical protein that is found associated with plasma HDL in various pathological conditions, such as acute or chronic inflammation. Cellular lipid release and generation of HDL by this protein were investigated, in comparison with the reactions by apolipoprotein A-I (apoA-I) and several types of cells that appear with various specific profiles of cholesterol and phospholipid release. SAA mediated cellular lipid release from these cells with the same profile as apoA-I. Upregulation of cellular ABCA1 protein by liver X receptor/retinoid X receptor agonists resulted in an increase of cellular lipid release by apoA-I and SAA. SAA reacted with the HEK293-derived clones that stably express human ABCA1 (293/2c) or ABCA7 (293/6c) to generate cholesterol-containing HDL in a similar manner to apoA-I. Dibutyryl cyclic AMP and phorbol 12-myristate 13-acetate, which differentiate apoA-I-mediated cellular lipid release between 293/2c and 293/6c, also exhibited the same differential effects on the SAA-mediated reactions. No evidence was found for the ABCA1/ABCA7-independent lipid release by SAA. Characterization of physicochemical properties of the HDL revealed that SAA-generated HDL particles had higher density, larger diameter, and slower electrophoretic mobility than those generated by apoA-I. These results demonstrate that SAA generates cholesterol-containing HDL directly with cellular lipid and that the reaction is mediated by ABCA1 and ABCA7. PMID:16607034

Abe-Dohmae, Sumiko; Kato, Koichi H; Kumon, Yoshitaka; Hu, Wei; Ishigami, Hideaki; Iwamoto, Noriyuki; Okazaki, Mitsuyo; Wu, Chen-Ai; Tsujita, Maki; Ueda, Kazumitsu; Yokoyama, Shinji

2006-07-01

160

Elongation of mouse prion protein amyloid-like fibrils: effect of temperature and denaturant concentration.  

Science.gov (United States)

Prion protein is known to have the ability to adopt a pathogenic conformation, which seems to be the basis for protein-only infectivity. The infectivity is based on self-replication of this pathogenic prion structure. One of possible mechanisms for such replication is the elongation of amyloid-like fibrils. We measured elongation kinetics and thermodynamics of mouse prion amyloid-like fibrils at different guanidine hydrochloride (GuHCl) concentrations. Our data show that both increases in temperature and GuHCl concentration help unfold monomeric protein and thus accelerate elongation. Once the monomers are unfolded, further increases in temperature raise the rate of elongation, whereas the addition of GuHCl decreases it. We demonstrated a possible way to determine different activation energies of amyloid-like fibril elongation by using folded and unfolded protein molecules. This approach separates thermodynamic data for fibril-assisted monomer unfolding and for refolding and formation of amyloid-like structure. PMID:24747600

Milto, Katazyna; Michailova, Ksenija; Smirnovas, Vytautas

2014-01-01

161

Soluble aggregates of the amyloid-? peptide are trapped by serum albumin to enhance amyloid-? activation of endothelial cells  

OpenAIRE

Abstract Background Self-assembly of the amyloid-? peptide (A?) has been implicated in the pathogenesis of Alzheimer's disease (AD). As a result, synthetic molecules capable of inhibiting A? self-assembly could serve as therapeutic agents and endogenous molecules that modulate A? self-assembly may influence disease progression. However, increasing evidence implicating a principal pathogenic role for small soluble A? aggregates warns that inhibition at intermediate stages...

Gonzalez-Velasquez Francisco J; Reyes Barcelo Adriana A; Moss Melissa A

2009-01-01

162

The role of protein hydrophobicity in conformation change and self-assembly into large amyloid fibers.  

Science.gov (United States)

It has been found that a short hydrophobic "template" peptide and a larger ?-helical "adder" protein cooperatively self-assemble into micrometer sized amyloid fibers. Here, a common template of trypsin hydrolyzed gliadin is combined with six adder proteins (?-casein, ?-lactalbumin, amylase, hemoglobin, insulin, and myoglobin) to determine what properties of the adder protein drive amyloid self-assembly. Utilizing Fourier Transform-Infrared (FT-IR) spectroscopy, the Amide I absorbance reveals that the observed decrease in ?-helix with time is approximately equal to the increase in high strand density ?-sheet, which is indicative of amyloid formation. The results show that the hydrophobic moment is a good predictor of conformation change but the fraction of aliphatic amino acids within the ?-helices is a better predictor. Upon drying, the protein mixtures form large amyloid fibers. The fiber twist is dependent on the aliphatic index and molecular weight of the adder protein. Here we demonstrate that it is possible to predict the propensity of an adder protein to unfold into an amyloid structure and to predict the fiber morphology, both from adder protein molecular features, which can be applied to the pragmatic engineering of large amyloid fibers. PMID:24601565

Ridgley, Devin M; Claunch, Elizabeth C; Lee, Parker W; Barone, Justin R

2014-04-14

163

The Role of Phospholipase D in Amyloid Precursor Protein Processing  

Directory of Open Access Journals (Sweden)

Full Text Available The generation of a secreted N-terminal fragment of the amyloid precursor protein (A PPs can be stimulated by a variety of signaling pathways many of which are also known to modulate the activity of the phospholipase D (PLD enzyme. This study used primary rat neuronal cerebellar granule (CG cultures and SH-SY5Y human neuroblastoma cell lines to determine the potential role of PLD in the protein kinase C (PKC-associated generation of A PPs. Protein release was markedly enhanced by direct PKC stimulation following treatment of both cell type with either phorbol ester or indirectly by the muscarinic agonist carbachol and these effects were greatly attenuated by co-incubation with the PKC inhibitor GF109203X. A partial inhibition of PKC- and carbachol-stimulated A PPs secretion was also achieved by pre-treatment of the cells with toxin B, a PLD inhibitor. This suggested that PLD may play a role downstream of PKC in the control of A PPs secretion.

Mark McLaughlin

2005-01-01

164

FTIR reveals structural differences between native ?-sheet proteins and amyloid fibrils  

OpenAIRE

The presence of ?-sheets in the core of amyloid fibrils raised questions as to whether or not ?-sheet-containing proteins, such as transthyretin, are predisposed to form such fibrils. However, we show here that the molecular structure of amyloid fibrils differs more generally from the ?-sheets in native proteins. This difference is evident from the amide I region of the infrared spectrum and relates to the distribution of the ?/? dihedral angles within the Ramachandran plot, the average ...

Zandomeneghi, Giorgia; Krebs, Mark R. H.; Mccammon, Margaret G.; Fa?ndrich, Marcus

2004-01-01

165

Increased Neuronal ?-Amyloid Precursor Protein Expression in Human Temporal Lobe Epilepsy: Association with Interleukin-1? Immunoreactivity  

OpenAIRE

Levels of immunoreactive ?-amyloid precursor protein and interleukin-1? were found to be elevated in surgically resected human temporal lobe tissue from patients with intractable epilepsy compared with postmortem tissue from neurologically unaffected patients (controls). In tissue from epileptics, the levels of the 135-kDa ?-amyloid precursor protein isoform were elevated to fourfold (p < 0.05) those of controls and those of the 130-kDa isoform to threefold (p < 0.05), whereas those of the...

Sheng, Jin G.; Boop, Frederick A.; Mrak, Robert E.; Griffin, W. Sue T.

1994-01-01

166

Effect of trichostatin a on gelsolin levels, proteolysis of amyloid precursor protein, and amyloid Beta-protein load in the brain of transgenic mouse model of Alzheimer's disease.  

Science.gov (United States)

In vivo and in vitro studies have shown that gelsolin is an anti-amyloidogenic protein. Trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, promotes the expression of gelsolin. Fibrillized amyoid beta-protein (A?) is a key constituent of amyloid plaques in the brains of patients with Alzheimer's disease (AD). We studied the effects of TSA on the levels of gelsolin; amyloid precursor protein (APP); proteolytic enzymes (?-secretase and ?-secretase) responsible for the production of A?; A?-cleaving enzymes, i.e., neprilysin (NEP) and insulin-degrading enzyme (IDE); and amyloid load in the double transgenic (Tg) APPswe/PS1?E9 mouse model of AD. Intraperitoneal injection of TSA for two months (9-11 months of age) resulted in decreased activity of HDAC, and increased levels of gelsolin in the hippocampus and cortex of the brain in AD Tg mice as compared to vehicle-treated mice. TSA also increased the levels of γ-secretase and ?-secretase activity in the brain. However, TSA did not show any effect on the activities or the expression levels of NEP and IDE in the brain. Furthermore, TSA treatment of AD Tg mice showed no change in the amyloid load (percent of examined area occupied by amyloid plaques) in the hippocampus and cortex, suggesting that TSA treatment did not result in the reduction of amyloid load. Interestingly, TSA prevented the formation of new amyloid deposits but increased the size of existing plaques. TSA treatment did not cause any apoptosis in the brain. These results suggest that TSA increases gelsolin expression in the brain, but the pleiotropic effects of TSA negate the anti-amyloidogenic effect of gelsolin in AD Tg mice. PMID:25387339

Yang, Wenzhong; Chauhan, Abha; Wegiel, Jerzy; Kuchna, Izabela; Gu, Feng; Chauhan, Ved

2014-01-01

167

Novel Role of RanBP9 in BACE1 Processing of Amyloid Precursor Protein and Amyloid ? Peptide Generation*S?  

OpenAIRE

Accumulation of the amyloid ? (A?) peptide derived from the proteolytic processing of amyloid precursor protein (APP) is the defining pathological hallmark of Alzheimer disease. We previously demonstrated that the C-terminal 37 amino acids of lipoprotein receptor-related protein (LRP) robustly promoted A? generation independent of FE65 and specifically interacted with Ran-binding protein 9 (RanBP9). In this study we found that RanBP9 strongly increased BACE1 cleavag...

Lakshmana, Madepalli K.; Yoon, Il-sang; Chen, Eunice; Bianchi, Elizabetta; Koo, Edward H.; Kang, David E.

2009-01-01

168

Acute-Phase Serum Amyloid A as a Marker of Insulin Resistance in Mice  

Directory of Open Access Journals (Sweden)

Full Text Available Acute-phase serum amyloid A (A-SAA was shown recently to correlate with obesity and insulin resistance in humans. However, the mechanisms linking obesity-associated inflammation and elevated plasma A-SAA to insulin resistance are poorly understood. Using high-fat diet- (HFD- fed mice, we found that plasma A-SAA was increased early upon HFD feeding and was tightly associated with systemic insulin resistance. Plasma A-SAA elevation was due to induction of Saa1 and Saa2 expression in liver but not in adipose tissue. In adipose tissue Saa3 was the predominant isoform and the earliest inflammatory marker induced, suggesting it is important for initiation of adipose tissue inflammation. To assess the potential impact of A-SAA on adipose tissue insulin resistance, we treated 3T3-L1 adipocytes with recombinant A-SAA. Intriguingly, physiological levels of A-SAA caused alterations in gene expression closely resembling those observed in HFD-fed mice. Proinflammatory genes (Ccl2, Saa3 were induced while genes critical for insulin sensitivity (Irs1, Adipoq, Glut4 were down-regulated. Our data identify HFD-fed mice as a suitable model to study A-SAA as a biomarker and a novel possible mediator of insulin resistance.

Klaus Seedorf

2008-06-01

169

Serum amyloid P component inhibits influenza A virus infections: in vitro and in vivo studies.  

DEFF Research Database (Denmark)

Serum amyloid P component (SAP) binds in vitro Ca(2+)-dependently to several ligands including oligosaccharides with terminal mannose and galactose. We have earlier reported that SAP binds to human influenza A virus strains, inhibiting hemagglutinin (HA) activity and virus infectivity in vitro. These studies were extended to comprise five mouse-adapted influenza A strains, two swine influenza A strains, a mink influenza A virus, a ferret influenza A reassortant virus, a influenza B virus and a parainfluenza 3 virus. The HA activity of all these viruses was inhibited by SAP. Western blotting showed that SAP bound to HA trimers, monomers and HA1 and HA2 subunits of influenza A virus. Binding studies indicated that galactose, mannose and fucose moieties contributed to the SAP reacting site(s). Intranasal administration of human SAP to mice induced no demonstrable toxic reactions, and circulating antibodies against SAP were not detected. Preincubation of virus (A/Japan/57) with SAP prevented primary infection of mice and development of antiviral antibodies. After a single intranasal administration of SAP (40 microg) 1 h before primary infection with virus (2LD(50)), nine out of 10 mice survived on day 10 and these mice approached normal body weight, whereas control mice (one out of five surviving on day 10) died. The data provide evidence of the potential of intranasally administered SAP for prophylactic treatment of influenza A virus infections in humans.

Horvath, A; Andersen, I

2001-01-01

170

Ribonuclease A suggests how proteins self-chaperone against amyloid fiber formation  

Energy Technology Data Exchange (ETDEWEB)

Genomic analyses have identified segments with high fiber-forming propensity in many proteins not known to form amyloid. Proteins are often protected from entering the amyloid state by molecular chaperones that permit them to fold in isolation from identical molecules; but, how do proteins self-chaperone their folding in the absence of chaperones? Here, we explore this question with the stable protein ribonuclease A (RNase A). We previously identified fiber-forming segments of amyloid-related proteins and demonstrated that insertion of these segments into the C-terminal hinge loop of nonfiber-forming RNase A can convert RNase A into the amyloid state through three-dimensional domain-swapping, where the inserted fiber-forming segments interact to create a steric zipper spine. In this study, we convert RNase A into amyloid-like fibers by increasing the loop length and hence conformational freedom of an endogenous fiber-forming segment, SSTSAASS, in the N-terminal hinge loop. This is accomplished by sandwiching SSTSAASS between inserted Gly residues. With these inserts, SSTSAASS is now able to form the steric zipper spine, allowing RNase A to form amyloid-like fibers. We show that these fibers contain RNase A molecules retaining their enzymatic activity and therefore native-like structure. Thus, RNase A appears to prevent fiber formation by limiting the conformational freedom of this fiber-forming segment from entering a steric zipper. Our observations suggest that proteins have evolved to self-chaperone by using similar protective mechanisms.

Teng, Poh K.; Anderson, Natalie J.; Goldschmidt, Lukasz; Sawaya, Michael R.; Sambashivan, Shilpa; Eisenberg, David (UCB)

2012-05-29

171

Protein Folding and Aggregation into Amyloid: The Interference by Natural Phenolic Compounds  

Directory of Open Access Journals (Sweden)

Full Text Available Amyloid aggregation is a hallmark of several degenerative diseases affecting the brain or peripheral tissues, whose intermediates (oligomers, protofibrils and final mature fibrils display different toxicity. Consequently, compounds counteracting amyloid aggregation have been investigated for their ability (i to stabilize toxic amyloid precursors; (ii to prevent the growth of toxic oligomers or speed that of fibrils; (iii to inhibit fibril growth and deposition; (iv to disassemble preformed fibrils; and (v to favor amyloid clearance. Natural phenols, a wide panel of plant molecules, are one of the most actively investigated categories of potential amyloid inhibitors. They are considered responsible for the beneficial effects of several traditional diets being present in green tea, extra virgin olive oil, red wine, spices, berries and aromatic herbs. Accordingly, it has been proposed that some natural phenols could be exploited to prevent and to treat amyloid diseases, and recent studies have provided significant information on their ability to inhibit peptide/protein aggregation in various ways and to stimulate cell defenses, leading to identify shared or specific mechanisms. In the first part of this review, we will overview the significance and mechanisms of amyloid aggregation and aggregate toxicity; then, we will summarize the recent achievements on protection against amyloid diseases by many natural phenols.

Massimo Stefani

2013-06-01

172

Isolation of a pentraxin-like protein from rainbow trout serum  

DEFF Research Database (Denmark)

Serum amyloid P-component (SAP) is a glycoprotein consisting of five or ten noncovalently associated identical subunits of molecular weight 19,000-30,000. Herein we report the isolation and partial characterization of a SAP-like protein from rainbow trout serum. The protein was isolated by calcium-dependent binding to Sepharose followed by ion-exchange and size-exclusion chromatography. Rabbit antibody against human SAP reacted with the trout protein and the NH2-terminal sequence of 16 amino acids showed 60% identity with the first 15 residues of human SAP. SDS-PAGE and endoglycosidase treatment indicated that the trout protein is a glycoprotein in which five or six subunits are linked by disulphide bonds. The subunits have a molecular weight of 37,000 of which approximately 13% is due to carbohydrate. We propose to name the trout protein sulphide linked SAP (SL-SAP).

Jensen, L E; Petersen, T E

1995-01-01

173

Analysis of the acute phase responses of Serum Amyloid A, Haptoglobin and Type 1 Interferon in cattle experimentally infected with foot-and-mouth disease virus serotype O  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract A series of challenge experiments were performed in order to investigate the acute phase responses to foot-and-mouth disease virus (FMDV infection in cattle and possible implications for the development of persistently infected "carriers". The host response to infection was investigated through measurements of the concentrations of the acute phase proteins (APPs serum amyloid A (SAA and haptoglobin (HP, as well as the bioactivity of type 1 interferon (IFN in serum of infected animals. Results were based on measurements from a total of 36 infected animals of which 24 were kept for observational periods exceeding 28 days in order to determine the carrier-status of individual animals. The systemic host response to FMDV in infected animals was evaluated in comparison to similar measurements in sera from 6 mock-inoculated control animals. There was a significant increase in serum concentrations of both APPs and type 1 IFN in infected animals coinciding with the onset of viremia and clinical disease. The measured parameters declined to baseline levels within 21 days after inoculation, indicating that there was no systemically measurable inflammatory reaction related to the carrier state of FMD. There was a statistically significant difference in the HP response between carriers and non-carriers with a lower response in the animals that subsequently developed into FMDV carriers. It was concluded that the induction of SAA, HP and type 1 IFN in serum can be used as markers of acute infection by FMDV in cattle.

Stenfeldt Carolina

2011-05-01

174

Biochemical studies in Normal Pressure Hydrocephalus (NPH) patients: Change in CSF levels of amyloid precursor protein (APP), amyloid-beta (A?) peptide and phospho-tau  

OpenAIRE

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 ?-amyloid precursor protein (sAPP), sAPP-alpha form (sAPP?), amyloid-beta (A?) peptide, total-tau protein and hyperp...

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

2010-01-01

175

Membrane-protein interactions hold the key to understanding amyloid formation  

CERN Document Server

In this perspective we describe the critical role membranes play in modulating the structures of the Amyloid Precursor Proteins to produce the peptides involved in the Alzheimer's disease. Some of the key concepts related to protein aggregation including the potential role of the excited states of monomers in initiating protein aggregation are described.

Straub, John E

2014-01-01

176

Predicted alpha-helical regions of the prion protein when synthesized as peptides form amyloid.  

OpenAIRE

By comparing the amino acid sequences of 11 mammalian and 1 avian prion proteins (PrP), structural analyses predicted four alpha-helical regions. Peptides corresponding to these regions of Syrian hamster PrP were synthesized, and, contrary to predictions, three of the four spontaneously formed amyloids as shown by electron microscopy and Congo red staining. By IR spectroscopy, these amyloid peptides exhibited secondary structures composed largely of beta-sheets. The first of the predicted hel...

Gasset, M.; Baldwin, M. A.; Lloyd, D. H.; Gabriel, J. M.; Holtzman, D. M.; Cohen, F.; Fletterick, R.; Prusiner, S. B.

1992-01-01

177

Dietary (?)-epicatechin as a potent inhibitor of ??-secretase amyloid precursor protein processing?  

OpenAIRE

Flavonoids, a group of dietary polyphenols have been shown to possess cognitive health benefits. Epidemiologic evidence suggests that they could play a role in risk reduction in dementia. Amyloid precursor protein processing and the subsequent generation of amyloid beta (A?) are central to the pathogenesis of Alzheimer's disease, as soluble, oligomeric A? is thought to be the toxic species driving disease progression. We undertook an in vitro screen to identify flavonoids with bioactivity ...

Cox, Carla J.; Choudhry, Fahd; Peacey, Eleanor; Perkinton, Michael S.; Richardson, Jill C.; Howlett, David R.; Lichtenthaler, Stefan F.; Francis, Paul T.; Williams, Robert J.

2015-01-01

178

Effects of cerebrovascular disease on amyloid precursor protein metabolites in cerebrospinal fluid  

OpenAIRE

Abstract Background Alzheimer's disease (AD) and cerebrovascular disease (CVD) including chronic small vessel disease of the brain (SVD) are the most frequent causes of dementia. AD is associated with metabolism of amyloid precursor protein (APP) and low levels of amyloid-? peptide (A?) X-42 in the cerebrospinal fluid (CSF). CVD and SVD are established risk factors for AD, brain white matter lesions (WML) are established surrogate markers for SVD and are also associated wit...

Rosengren Lars; Grambaite Ramune; Zetterberg Henrik; Blennow Kaj; Selnes Per; Johnsen Lisbeth; Stenset Vidar; Fladby Tormod

2010-01-01

179

Glycogen Synthase Kinase 3 Inhibition Promotes Lysosomal Biogenesis and Autophagic Degradation of the Amyloid-? Precursor Protein  

OpenAIRE

Alzheimer's disease (AD) has been associated with altered activity of glycogen synthase kinase 3 (GSK3) isozymes, which are proposed to contribute to both neurofibrillary tangles and amyloid plaque formation. However, the molecular basis by which GSK3 affects the formation of A? remains unknown. Our aim was to identify the underlying mechanisms of GSK3-dependent effects on the processing of amyloid precursor protein (APP). For this purpose, N2a cells stably expressing APP carrying the Swedis...

Parr, Callum; Carzaniga, Raffaela; Gentleman, Steve M.; Leuven, Fred; Walter, Jochen; Sastre, Magdalena

2012-01-01

180

Brain amyloid β protein and memory disruption in Alzheimer’s disease  

OpenAIRE

Weiming XiaCenter for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USAAbstract: The development of amyloid-containing neuritic plaques is an invariable characteristic of Alzheimer’s diseases (AD). The conversion from monomeric amyloid ? protein (A?) to oligomeric A? and finally neuritic plaques is highly dynamic. The specific Aß species that is correlated with disease...

Weiming Xia

2010-01-01

181

Investigation of amyloid deposition in uterine leiomyoma patients  

OpenAIRE

Objects: To investigate the pathogenesis of amyloid presented in uterine leiomyoma. Methods: 36 uterine leiomyoma patients were recruited and divided into two groups according to Congo red staining results. 6 cases are Congo red staining-positive, and 30 cases Congo red staining-negative which represented amyloid positive and amyloid negative respectively. All patients’ serum total protein (TP), albumin (Alb) and prealbumin (PA) levels were measured as well as blood hemoglobin (Hb), cell co...

Jinping Liu; Fei Zhai; Peng Ge; Jinhai Lu; Yi Qin; Xuguo Sun

2012-01-01

182

F-box only protein 2 (Fbxo2) regulates amyloid precursor protein levels and processing.  

Science.gov (United States)

The amyloid precursor protein (APP) is an integral membrane glycoprotein whose cleavage products, particularly amyloid-?, accumulate in Alzheimer disease (AD). APP is present at synapses and is thought to play a role in both the formation and plasticity of these critical neuronal structures. Despite the central role suggested for APP in AD pathogenesis, the mechanisms regulating APP in neurons and its processing into cleavage products remain incompletely understood. F-box only protein 2 (Fbxo2), a neuron-enriched ubiquitin ligase substrate adaptor that preferentially binds high-mannose glycans on glycoproteins, was previously implicated in APP processing by facilitating the degradation of the APP-cleaving ?-secretase, ?-site APP-cleaving enzyme. Here, we sought to determine whether Fbxo2 plays a similar role for other glycoproteins in the amyloid processing pathway. We present in vitro and in vivo evidence that APP is itself a substrate for Fbxo2. APP levels were decreased in the presence of Fbxo2 in non-neuronal cells, and increased in both cultured hippocampal neurons and brain tissue from Fbxo2 knock-out mice. The processing of APP into its cleavage products was also increased in hippocampi and cultured hippocampal neurons lacking Fbxo2. In hippocampal slices, this increase in cleavage products was accompanied by a significant reduction in APP at the cell surface. Taken together, these results suggest that Fbxo2 regulates APP levels and processing in the brain and may play a role in modulating AD pathogenesis. PMID:24469452

Atkin, Graham; Hunt, Jack; Minakawa, Eiko; Sharkey, Lisa; Tipper, Nathan; Tennant, William; Paulson, Henry L

2014-03-01

183

Evidence that the 42- and 40-amino acid forms of amyloid ? protein are generated from the ?-amyloid precursor protein by different?protease?activities  

Science.gov (United States)

Cerebral deposition of the amyloid ? protein (A?) is an early and invariant feature of Alzheimer disease (AD). Whereas the 40-amino acid form of A? (A?40) accounts for ?90% of all A? normally released from cells, it appears to contribute only to later phases of the pathology. In contrast, the longer more amyloidogenic 42-residue form (A?42), accounting for only ?10% of secreted A?, is deposited in the earliest phase of AD and remains the major constituent of most amyloid plaques throughout the disease. Moreover, its levels have been shown to be increased in all known forms of early-onset familial AD. Thus, inhibition of A?42 production is a prime therapeutic goal. The same protease, ?-secretase, is assumed to generate the C termini of both A?40 and A?42. Herein, we analyze the effect of the compound MDL 28170, previously suggested to inhibit ?-secretase, on ?-amyloid precursor protein processing. By immunoprecipitating conditioned medium of different cell lines with various A?40- and A?42-specific antibodies, we demonstrate a much stronger inhibition of the ?-secretase cleavage at residue 40 than of that at residue 42. These data suggest that different proteases generate the A?40 and A?42 C termini. Further, they raise the possibility of identifying compounds that do not interfere with general ?-amyloid precursor protein metabolism, including A?40 production, but specifically block the generation of the pathogenic A?42 peptide. PMID:8917563

Citron, Martin; Diehl, Thekla?S.; Gordon, Grace; Biere, Anja?Leona; Seubert, Peter; Selkoe, Dennis?J.

1996-01-01

184

Oxysterol-binding protein-1 (OSBP1 modulates processing and trafficking of the amyloid precursor protein  

Directory of Open Access Journals (Sweden)

Full Text Available Background Evidence from biochemical, epidemiological and genetic findings indicates that cholesterol levels are linked to amyloid-? (A? production and Alzheimer's disease (AD. Oxysterols, which are cholesterol-derived ligands of the liver X receptors (LXRs and oxysterol binding proteins, strongly regulate the processing of amyloid precursor protein (APP. Although LXRs have been studied extensively, little is known about the biology of oxysterol binding proteins. Oxysterol-binding protein 1 (OSBP1 is a member of a family of sterol-binding proteins with roles in lipid metabolism, regulation of secretory vesicle generation and signal transduction, and it is thought that these proteins may act as sterol sensors to control a variety of sterol-dependent cellular processes. Results We investigated whether OSBP1 was involved in regulating APP processing and found that overexpression of OSBP1 downregulated the amyloidogenic processing of APP, while OSBP1 knockdown had the opposite effect. In addition, we found that OSBP1 altered the trafficking of APP-Notch2 dimers by causing their accumulation in the Golgi, an effect that could be reversed by treating cells with OSBP1 ligand, 25-hydroxycholesterol. Conclusion These results suggest that OSBP1 could play a role in linking cholesterol metabolism with intracellular APP trafficking and A? production, and more importantly indicate that OSBP1 could provide an alternative target for A?-directed therapeutic.

Seabrook Guy R

2008-03-01

185

Effects of Janus kinase inhibitor tofacitinib on circulating serum amyloid A and interleukin-6 during treatment for rheumatoid arthritis.  

Science.gov (United States)

The Janus kinase inhibitor tofacitinib is currently being investigated as a disease-modifying agent in rheumatoid arthritis (RA). We investigated the in-vivo effects of tofacitinib treatment for 4 weeks on elevated circulating acute-phase serum amyloid (SAA) levels in 14 Japanese patients with RA. SAA levels fell from 110·5?±?118·5??g/ml (mean?±?standard deviation) at treatment initiation to 15·3?±?13·3??g/ml after 4 weeks treatment with tofacitinib. The reduction in SAA levels was greater in patients receiving tofacitinib plus methotrexate compared with those receiving tofacitinib monotherapy. Tofacitinib was also associated with reduced serum interleukin (IL)-6, but had no effect on serum levels of soluble IL-6 receptor. Patients were divided into groups with adequate (normalization) and inadequate SAA responses (without normalization). Serum IL-6 levels were reduced more in the group with adequate SAA response compared with those with inadequate SAA response. These results suggest that tofacitinib down-regulates the proinflammatory cytokine, IL-6, accompanied by reduced serum SAA levels in patients with active RA. The ability to regulate elevated serum IL-6 and SAA levels may explain the anti-inflammatory activity of tofacitinib. PMID:24665995

Migita, K; Izumi, Y; Jiuchi, Y; Kozuru, H; Kawahara, C; Izumi, M; Sakai, T; Nakamura, M; Motokawa, S; Nakamura, T; Kawakami, A

2014-02-01

186

Amyloid-beta peptide binds to microtubule-associated protein 1B (MAP1B).  

Science.gov (United States)

Extracellular and intraneuronal formation of amyloid-beta aggregates have been demonstrated to be involved in the pathogenesis of Alzheimer's disease. However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of targets have deleterious effects on cellular functions. In the present study we have shown for the first time that amyloid-beta 1-42 bound to a peptide comprising the microtubule binding domain of the heavy chain of microtubule-associated protein 1B by the screening of a human brain cDNA library expressed on M13 phage. This interaction may explain, in part, the loss of neuronal cytoskeletal integrity, impairment of microtubule-dependent transport and synaptic dysfunction observed previously in Alzheimer's disease. PMID:18079022

Gevorkian, Goar; Gonzalez-Noriega, Alfonso; Acero, Gonzalo; Ordoñez, Jorge; Michalak, Colette; Munguia, Maria Elena; Govezensky, Tzipe; Cribbs, David H; Manoutcharian, Karen

2008-05-01

187

AMYLOID-? PEPTIDE BINDS TO MICROTUBULE-ASSOCIATED PROTEIN 1B (MAP1B)  

Science.gov (United States)

Extracellular and intraneuronal formation of amyloid-beta aggregates have been demonstrated to be involved in the pathogenesis of Alzheimer’s disease. However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of targets have deleterious effects on cellular functions. In the present study we have shown for the first time that amyloid-beta 1-42 bound to a peptide comprising the microtubule binding domain of the heavy chain of microtubule-associated protein 1B by the screening of a human brain cDNA library expressed on M13 phage. This interaction may explain, in part, the loss of neuronal cytoskeletal integrity, impairment of microtubule-dependent transport and synaptic dysfunction observed previously in Alzheimer’s disease. PMID:18079022

Gevorkian, Goar; Gonzalez-Noriega, Alfonso; Acero, Gonzalo; Ordoñez, Jorge; Michalak, Colette; Munguia, Maria Elena; Govezensky, Tzipe; Cribbs, David H.; Manoutcharian, Karen

2008-01-01

188

Self-assembling of amyloid-like proteins  

Energy Technology Data Exchange (ETDEWEB)

Full text: Septins are proteins from the GTP-binding family and participate in cell division cycle performing functions such as secretion and cytoskeletal division. They can also be found in neurodegenerative conditions as Alzheimers and Parkinson's diseases, forming highly organized fiber-like aggregates known as amyloids. In this work, we used small angle x-ray scattering (SAXS) to investigate the formation and time evolution of septins aggregates under the influence of temperature and concentration. The SAXS measurements were performed with the GTPase domain of human Septin 2 (SEPT2G) at 0.5 and 1 mg/mL and temperatures between 4 and 45 deg C. At 0.5 mg/mL and 4 deg C, the protein self-aggregates as a dimer, being stable over one hour of observation. When the temperature was increased to 15 deg C, the results demonstrate that cylinder-like aggregates are formed and coexist with some dimer population and a small amount of larger aggregates. However, the number of very large aggregates increases with time concomitantly with the decrease of cylinder amount in the solution. At 37 deg C cylinder-like aggregates are not longer present in solution, whereas a significant amount of dimers decreases from 50% to 20% in less than 1 hour. At 45 deg C such an effect is even more accentuated: the percentage of dimers is only 6% in solution into a favor of 94% of very larger aggregates. When we analyze the protein at 1 mg/mL, at 4 deg C cylinder-like aggregates (36 nm-long and 12 nm-cross section) are already formed, coexisting with dimers and, as occurred for lower concentration, the two populations remained unchanged over one hour of observation. Out results also indicate that the dimensions of these cylinders increase with the concentration and the percentage of cylinders and larger aggregates are higher than those found for 0.5 mg/mL. In conclusion, our results showed the coexistence of dimers of SEPT2G with small fibers and larger aggregates in solution that evolve not only with concentration and temperature but also with time. (author)

Sales, E.M.; Barbosa, L.R.S.; Itri, R. [Universidade de Sao Paulo (USP), SP (Brazil); Damalio, J.C.P.; Araujo, A.P.U. [Universidade de Sao Paulo (USP-SC), Sao Carlos, SP (Brazil); Spinozzi, F.; Mariani, P. [Universita Politecnica delle Marche, Ancona (Italy)

2012-07-01

189

Amyloid beta 42 peptide (A?42)-lowering compounds directly bind to A? and interfere with amyloid precursor protein (APP) transmembrane dimerization  

OpenAIRE

Following ectodomain shedding by ?-secretase, successive proteolytic cleavages within the transmembrane sequence (TMS) of the amyloid precursor protein (APP) catalyzed by ?-secretase result in the release of amyloid-? (A?) peptides of variable length. A? peptides with 42 amino acids appear to be the key pathogenic species in Alzheimer’s disease, as they are believed to initiate neuronal degeneration. Sulindac sulfide, which is known as a potent ?-secretase modulator (GSM), selectively...

Richter, Luise; Munter, Lisa-marie; Ness, Julia; Hildebrand, Peter W.; Dasari, Muralidhar; Unterreitmeier, Stephanie; Bulic, Bruno; Beyermann, Michael; Gust, Ronald; Reif, Bernd; Weggen, Sascha; Langosch, Dieter; Multhaup, Gerd

2010-01-01

190

Biotechnologically engineered protein binders for applications in amyloid diseases.  

Science.gov (United States)

The aberrant self-assembly of polypeptide chains into amyloid structures is a common phenomenon in several neurodegenerative diseases, systemic amyloidosis, and 'normal' aging. Improvements in laboratory-scale detection of these structures, their clinical diagnosis, and the treatment of disease likely depend on the advent of new molecules that recognize particular states or induce their clearance in vivo. This review will describe what biotechnology can do to generate proteinaceous amyloid-binders, explain their molecular recognition mechanisms, and summarize possibilities to functionalize further these ligands for specific applications. PMID:25168412

Haupt, Christian; Fändrich, Marcus

2014-10-01

191

Serum amyloid A and pairing formyl peptide receptor 2 are expressed in corneas and involved in inflammation-mediated neovascularization  

Directory of Open Access Journals (Sweden)

Full Text Available AIM:To solidify the involvement of Saa-related pathway in corneal neovascularization (CorNV. The pathogenesis of inflammatory CorNV is not fully understood yet, and our previous study implicated that serum amyloid A (Saa 1 (Saa1 and Saa3 were among the genes up-regulated upon CorNV induction in mice.METHODS:Microarray data obtained during our profiling project on CorNV were analyzed for the genes encoding the four SAA family members (Saa1-4, six reported SAA receptors (formyl peptide receptor 2, Tlr2, Tlr4, Cd36, Scarb1, P2rx7 and seven matrix metallopeptidases (Mmp 1a, 1b, 2, 3, 9, 10, 13 reportedly to be expressed upon SAA pathway activation. The baseline expression or changes of interested genes were further confirmed in animals with CorNV using molecular or histological methods. CorNV was induced in Balb/c and C57BL/6 mice by placing either three interrupted 10-0 sutures or a 2 mm filter paper soaked with sodium hydroxide in the central area of the cornea. At desired time points, the corneas were harvested for histology examination or for extraction of mRNA and protein. The mRNA levels of Saa1, Saa3, Fpr2, Mmp2 and Mmp3 in corneas were detected using quantitative reverse transcription-PCR, and SAA3 protein in tissues detected using immunohistochemistry or western blotting.RESULTS:Microarray data analysis revealed that Saa1, Saa3, Fpr2, Mmp2, Mmp3 messengers were readily detected in normal corneas and significantly up-regulated upon CorNV induction. The changes of these five genes were confirmed with real-time PCR assay. On the contrary, other SAA members (Saa2, Saa4, other SAA receptors (Tlr2, Tlr4, Cd36, P2rx7, etc, or other Mmps (Mmp1a, Mmp1b, Mmp9, Mmp10, Mmp13 did not show consistent changes. Immunohistochemistry study and western blotting further confirmed the expression of SAA3 products in normal corneas as well as their up-regulation in corneas with CorNV.CONCLUSION:SAA-FPR2 pathway composing genes were expressed in normal murine corneas and, upon inflammatory stimuli challenge to the corneas, their expressions were up-regulated, suggesting their roles in pathogenesis of CorNV. The potential usefulness of SAA-FPR2 targets in future management of CorNV-related diseases deserves investigation.

Sheng-Wei Ren

2014-04-01

192

Relevance of amyloid precursor-like protein 2 C-terminal fragments in pancreatic cancer cells  

OpenAIRE

In some cellular systems, particularly neurons, amyloid precursor-like protein 2 (APLP2), and its highly homologous family member amyloid precursor protein (APP), have been linked to cellular growth. APLP2 and APP undergo regulated intramembrane proteolysis to produce C-terminal fragments. In this study, we found comprehensive expression of APLP2 C-terminal fragments in a panel of pancreatic cancer cell lines; however, APP C-terminal fragments were notably limited to the BxPC3 cell line. Exte...

Peters, Haley L.; Tuli, Amit; Wang, Xiaojian; Liu, Cuiling; Pan, Zenggang; Ouellette, Michel M.; Hollingsworth, Michael A.; Macdonald, Richard G.; Solheim, Joyce C.

2012-01-01

193

Serum amyloid A-luciferase transgenic mice: response to sepsis, acute arthritis, and contact hypersensitivity and the effects of proteasome inhibition.  

Science.gov (United States)

Acute phase serum amyloid A proteins (A-SAAs) are multifunctional apolipoproteins produced in large amounts during the acute phase of an inflammation and also during the development of chronic inflammatory diseases. In this study we present a Saa1-luc transgenic mouse model in which SAA1 gene expression can be monitored by measuring luciferase activity using a noninvasive imaging system. When challenged with LPS, TNF-alpha, or IL-1beta, in vivo imaging of Saa1-luc mice showed a 1000- to 3000-fold induction of luciferase activity in the hepatic region that peaked 4-7 h after treatment. The induction of liver luciferase expression was consistent with an increase in SAA1 mRNA in the liver and a dramatic elevation of the serum SAA1 concentration. Ex vivo analyses revealed luciferase induction in many tissues, ranging from several-fold (brain) to >5000-fold (liver) after LPS or TNF-alpha treatment. Pretreatment of mice with the proteasome inhibitor bortezomib significantly suppressed LPS-induced SAA1 expression. These results suggested that proteasome inhibition, perhaps through the NF-kappaB signaling pathway, may regulate SAA1 expression. During the development of acute arthritis triggered by intra-articular administration of zymosan, SAA1 expression was induced both locally at the knee joint and systemically in the liver, and the induction was significantly suppressed by bortezomib. Induction of SAA1 expression was also demonstrated during contact hypersensitivity induced by topical application of oxazolone. These results suggest that both local and systemic induction of A-SAA occur during inflammation and may contribute to the pathogenesis of chronic inflammatory diseases associated with amyloid deposition. PMID:15944321

Zhang, Ning; Ahsan, Muhammad H; Purchio, Anthony F; West, David B

2005-06-15

194

Amyloid-clearing proteins and their epigenetic regulation as a therapeutic target in Alzheimer's disease.  

Science.gov (United States)

Abnormal elevation of amyloid ?-peptide (A?) levels in the brain is the primary trigger for neuronal cell death specific to Alzheimer's disease (AD). It is now evident that A? levels in the brain are manipulable due to a dynamic equilibrium between its production from the amyloid precursor protein (APP) and removal by amyloid clearance proteins. Clearance can be either enzymic or non-enzymic (binding/transport proteins). Intriguingly several of the main amyloid-degrading enzymes (ADEs) are members of the M13 peptidase family (neprilysin (NEP), NEP2 and the endothelin converting enzymes (ECE-1 and -2)). A distinct metallopeptidase, insulin-degrading enzyme (IDE), also contributes to A? degradation in the brain. The ADE family currently embraces more than 20 members, both membrane-bound and soluble, and of differing cellular locations. NEP plays an important role in brain function terminating neuropeptide signals. Its decrease in specific brain areas with age or after hypoxia, ischaemia or stroke contribute significantly to the development of AD pathology. The recently discovered mechanism of epigenetic regulation of NEP (and other genes) by the APP intracellular domain (AICD) and its dependence on the cell type and APP isoform expression suggest possibilities for selective manipulation of NEP gene expression in neuronal cells. We have also observed that another amyloid-clearing protein, namely transthyretin (TTR), is also regulated in the neuronal cell by a mechanism similar to NEP. Dependence of amyloid clearance proteins on histone deacetylases and the ability of HDAC inhibitors to up-regulate their expression in the brain opens new avenues for developing preventive strategies in AD. PMID:25278875

Nalivaeva, Natalia N; Belyaev, Nikolai D; Kerridge, Caroline; Turner, Anthony J

2014-01-01

195

Structure of a Functional Amyloid Protein Subunit Computed Using Sequence Variation  

DEFF Research Database (Denmark)

Functional amyloid fibers, called curli, play a critical role in adhesion and invasion of many bacteria. Unlike pathological amyloids, curli structures are formed by polypeptide sequences whose amyloid structure has been selected for during evolution. This important distinction provides us with an opportunity to obtain structural insights from an unexpected source: the covariation of amino acids in sequences of different curli proteins. We used recently developed methods to extract amino acid contacts from a multiple sequence alignment of homologues of the curli subunit protein, CsgA. Together with an efficient force field, these contacts allow us to determine structural models of CsgA. We find that CsgA forms a ?-helical structure, where each turn corresponds to previously identified repeat sequences in CsgA. The proposed structure is validated by previously measured solid-state NMR, electron microscopy and X-ray diffraction data, and agrees with an earlier proposed model derived by complementary means.

Tian, Pengfei; Boomsma, Wouter

2014-01-01

196

Self-assembly of protein amyloid: a competition between amorphous and ordered aggregation  

CERN Document Server

Protein aggregation in the form of amyloid fibrils has important biological and technological implications. Although the self-assembly process is highly efficient, aggregates not in the fibrillar form would also occur and it is important to include these disordered species when discussing the thermodynamic equilibrium behavior of the system. Here, we initiate such a task by considering a mixture of monomeric proteins and the corresponding aggregates in the disordered form (micelles) and in the fibrillar form (amyloid fibrils). Starting with a model on the respective binding free energies for these species, we calculate their concentrations at thermal equilibrium. We then discuss how the incorporation of the disordered structure furthers our understanding on the various amyloid promoting factors observed empirically, and on the kinetics of fibrilization.

Lee, Chiu Fan

2010-01-01

197

Characterization of insulin degrading enzyme and other amyloid-? degrading proteases in human serum: a role in Alzheimer's disease?  

Science.gov (United States)

Sporadic Alzheimer's disease (AD) patients have low amyloid-? peptide (A?) clearance in the central nervous system. The peripheral A? clearance may also be important but its role in AD remains unclear. We aimed to study the A? degrading proteases including insulin degrading enzyme (IDE), angiotensin converting enzyme (ACE) and others in blood. Using the fluorogenic substrate V (a substrate of IDE and other metalloproteases), we showed that human serum degraded the substrate V, and the activity was inhibited by adding increasing dose of A?. The existence of IDE activity was demonstrated by the inhibition of insulin, amylin, or EDTA, and further confirmed by immunocapture of IDE using monoclonal antibodies. The involvement of ACE was indicated by the ability of the ACE inhibitor, lisinopril, to inhibit the substrate V degradation. To test the variations of substrate V degradation in humans, we used serum samples from a homebound elderly population with cognitive diagnoses. Compared with the elderly who had normal cognition, those with probable AD and amnestic mild cognitive impairment (amnestic MCI) had lower peptidase activities. Probable AD or amnestic MCI as an outcome remained negatively associated with serum substrate V degradation activity after adjusting for the confounders. The elderly with probable AD had lower serum substrate V degradation activity compared with those who had vascular dementia. The blood proteases mediating A? degradation may be important for the AD pathogenesis. More studies are needed to specify each A? degrading protease in blood as a useful biomarker and a possible treatment target for AD. PMID:22232014

Liu, Zhiheng; Zhu, Haihao; Fang, Guang Guang; Walsh, Kathryn; Mwamburi, Mkaya; Wolozin, Benjamin; Abdul-Hay, Samer O; Ikezu, Tsuneya; Leissring, Malcolm A; Qiu, Wei Qiao

2012-01-01

198

Mechanism of Neuronal versus Endothelial Cell Uptake of Alzheimer's Disease Amyloid ? Protein  

OpenAIRE

Alzheimer's disease (AD) is characterized by significant neurodegeneration in the cortex and hippocampus; intraneuronal tangles of hyperphosphorylated tau protein; and accumulation of ?-amyloid (A?) proteins 40 and 42 in the brain parenchyma as well as in the cerebral vasculature. The current understanding that AD is initiated by the neuronal accumulation of A? proteins due to their inefficient clearance at the blood-brain-barrier (BBB), places the neurovascular unit at the epicenter of AD...

Kandimalla, Karunya K.; Scott, Olenych G.; Fulzele, Smita; Davidson, Michael W.; Poduslo, Joseph F.

2009-01-01

199

Evidence that the 42- and 40-amino acid forms of amyloid beta protein are generated from the beta-amyloid precursor protein by different protease activities.  

Science.gov (United States)

Cerebral deposition of the amyloid beta protein (A beta) is an early and invariant feature of Alzheimer disease (AD). Whereas the 40-amino acid form of A beta (A beta 40) accounts for approximately 90% of all A beta normally released from cells, it appears to contribute only to later phases of the pathology. In contrast, the longer more amyloidogenic 42-residue form (A beta 42), accounting for only approximately 10% of secreted A beta, is deposited in the earliest phase of AD and remains the major constituent of most amyloid plaques throughout the disease. Moreover, its levels have been shown to be increased in all known forms of early-onset familial AD. Thus, inhibition of A beta 42 production is a prime therapeutic goal. The same protease, gamma-secretase, is assumed to generate the C termini of both A beta 40 and A beta 42. Herein, we analyze the effect of the compound MDL 28170, previously suggested to inhibit gamma-secretase, on beta-amyloid precursor protein processing. By immunoprecipitating conditioned medium of different cell lines with various A beta 40- and A beta 42-specific antibodies, we demonstrate a much stronger inhibition of the gamma-secretase cleavage at residue 40 than of that at residue 42. These data suggest that different proteases generate the A beta 40 and A beta 42 C termini. Further, they raise the possibility of identifying compounds that do not interfere with general beta-amyloid precursor protein metabolism, including A beta 40 production, but specifically block the generation of the pathogenic A beta 42 peptide. PMID:8917563

Citron, M; Diehl, T S; Gordon, G; Biere, A L; Seubert, P; Selkoe, D J

1996-11-12

200

Preparation of amyloid-like fibrils containing magnetic iron oxide nanoparticles: Effect of protein aggregation on proton relaxivity  

International Nuclear Information System (INIS)

Highlights: ? Preparation of amyloid materials labeled with magnetic iron oxide nanoparticles. ? Characterization of amyloid materials by electron tomography. ? Influence of protein aggregation on the magnetic nanoparticle properties. -- Abstract: A method to prepare amyloid-like fibrils functionalized with magnetic nanoparticles has been developed. The amyloid-like fibrils are prepared in a two step procedure, where insulin and magnetic nanoparticles are mixed simply by grinding in the solid state, resulting in a water soluble hybrid material. When the hybrid material is heated in aqueous acid, the insulin/nanoparticle hybrid material self assembles to form amyloid-like fibrils incorporating the magnetic nanoparticles. This results in magnetically labeled amyloid-like fibrils which has been characterized by Transmission Electron Microscopy (TEM) and electron tomography. The influence of the aggregation process on proton relaxivity is investigated. The prepared materials have potential uses in a range of bio-imaging applications.

201

Vitamin D binding protein as a serum biomarker of Alzheimer's disease.  

Science.gov (United States)

Vitamin D binding protein (VDBP), a multifunctional protein, has been found to be elevated in the cerebrospinal fluid (CSF) of neurodegenerative disorder cases, implicating it in the pathogenesis of Alzheimer's disease (AD). However, the contribution of VDBP to AD has not been fully explored. We used a Multiple Indicators Multiple Causes (MIMIC) approach to examine the relationship between serum VDBP levels and cognitive performance in a well characterized AD cohort, the Texas Alzheimer's Research and Care Consortium (TARCC). Instead of categorical diagnoses, we used a latent dementia phenotype (d), which has been validated in several prior studies using this dataset. We found that serum VDBP levels are significantly positively associated with d scores, which in turn are inversely related to cognitive performance. This suggests that d mediates the adverse effects of serum VDB on cognition and therefore that its effects are specifically dementing. d scores are also specifically related to default mode network (DMN) structure. VDBP acts as an amyloid-? (A?) scavenger, and A? deposition in the DMN is seen in the pre-clinical stages of AD. We speculate then that serum effects of VDBP are mediated through changes in DMN structure or function, most probably via A?. A? affects the DMN early in the course of AD. Therefore, raised serum VDBP levels may be a useful indicator of future dementia and/or dementia conversion. This might be confirmed through longitudinal analysis of TARCC data. PMID:25079796

Bishnoi, Ram J; Palmer, Raymond F; Royall, Donald R

2015-01-01

202

99mTc-MAMA-chrysamine G, a probe for beta-amyloid protein of Alzheimer's disease  

International Nuclear Information System (INIS)

Chrysamine G (CG), an analogue of Congo red, is known to bind in vitro to the ?-amyloid protein (A? 10-43) and to homogenates of several regions of the brain of Alzheimer's disease (AD) patients. We synthesised a conjugate of 2-(acetamido)-CG with a bis-S-trityl protected monoamide-monoaminedithiol (MAMA-Tr2) tetraligand, which was efficiently deprotected and labelled with a 75% yield with technetium-99m, to obtain 99mTc-MAMA-CG. In mice, 99mTc-MAMA-CG was cleared mainly by the hepatobiliary system, resulting in a fast blood clearance. Brain uptake of 99mTc-MAMA-CG was low. Co-injection with the blood pool tracer iodine-125 human serum albumin (125I-HSA) demonstrated a brain/blood activity ratio for 99mTc-MAMA-CG that was significantly higher than that for 125I-HSA (t test for dependent samples, P99mTc-MAMA-CG to cross the blood-brain barrier. In vitro autoradiography demonstrated pronounced binding of 99mTc-MAMA-CG to ?-amyloid deposits in autopsy sections of the parietal and occipital cortex of an AD patient as compared with controls. Adding 10 ?M Congo red during incubation displaced the binding of 99mTc-MAMA-CG. Congo red staining and autoradiography identified the same lesions. 99mTc-MAMA-CG seems to bind selectively to ?-amyloid deposition in human brain parenchyma and blood vessels in vitro and thus migh blood vessels in vitro and thus might be a lead compound for further development of a useful tracer agent for the in vivo diagnosis of Alzheimer's disease. (orig.)

203

Amyloid Beta Precursor Protein and Prion Protein Have a Conserved Interaction Affecting Cell Adhesion and CNS Development  

OpenAIRE

Genetic and biochemical mechanisms linking onset or progression of Alzheimer Disease and prion diseases have been lacking and/or controversial, and their etiologies are often considered independent. Here we document a novel, conserved and specific genetic interaction between the proteins that underlie these diseases, amyloid-? precursor protein and prion protein, APP and PRP, respectively. Knockdown of APP and/or PRNP homologs in the zebrafish (appa, appb, prp1, and prp2) produces a dose-dep...

Kaiser, Darcy M.; Acharya, Moulinath; Leighton, Patricia L. A.; Wang, Hao; Daude, Nathalie; Wohlgemuth, Serene; Shi, Beipei; Allison, W. Ted

2012-01-01

204

Molecular cloning, characterization of one key molecule of teleost innate immunity from orange-spotted grouper (Epinephelus coioides): serum amyloid A.  

Science.gov (United States)

The orange-spotted grouper (Epinephelus coioides), a favorite marine food fish, is widely cultured in China and Southeast Asian countries. However, little is known about its acute phase response (APR) caused by viral diseases. Serum amyloid A (SAA) is a major acute phase protein (APP). In this study, a new SAA homologous (EcSAA) gene was cloned from grouper, E. coioides, by rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA sequence of SAA was 508 bp and contained a 363 bp open reading frame (ORF) coding for a protein of 121 aa. Similar to other fish known SAA genes, the EcSAA gene contained four exons and three introns. Quantitative real-time PCR analysis revealed that EcSAA mRNA is predominately expressed in liver and gill of grouper. Furthermore, the expression of EcSAA was differentially up-regulated in liver after infection with Staphyloccocus aureus, Vibrio vulnificus, Vibrio parahaemolyticus, Saccharomyces cerevisiae and Singapore grouper iridovirus (SGIV). Recombinant EcSAA (rEcSAA) was expressed in Escherichia BL21 (DE3) and purified for mouse anti-EcSAA serum preparation. The rEcSAA fusion protein was demonstrated to bind to all tested bacteria and yeast, and inhibit the replication of SGIV. Overexpression of EcSAA in grouper spleen (GS) cells could also inhibit the replication of SGIV. These results suggest that EcSAA may be an important molecule in the innate immunity of grouper. PMID:23178260

Wei, Jingguang; Guo, Minglan; Ji, Huasong; Qin, Qiwei

2013-01-01

205

Serum total proteins and serum total cholesterol levels in Gaolao Cattle  

Directory of Open Access Journals (Sweden)

Full Text Available The healthy female Gaolao cattle were selected and divided in three groups of ten animals each with reference to age. The blood samples were processed for clear serum collection and estimation of serum total proteins, albumin, globulin, albumin and globulin ratio and serum total cholesterol. It is reported that female calves had low total proteins, albumin and globulin than the adult cows. [Veterinary World 2008; 1(4.000: 115-116

P. M. Kapale

2008-08-01

206

Effect of x-radiation on serum proteins  

International Nuclear Information System (INIS)

The inbred albine mice were exposed to 315 roentgen whole-body X-radiation at a rate of 22.5 roentgen per minute. Maximum decrease in the serum albumin and maximum increase in the serum globulin fractions were seen two hours after irradiation. Both of the serum proteins return to approximately normal levels within six hours. (author)

207

Feasibility of Predicting MCI/AD Using Neuropsychological Tests and Serum ?-Amyloid  

OpenAIRE

We examined the usefulness of brief neuropsychological tests and serum A? as a predictive test for detecting MCI/AD in older adults. Serum A? levels were measured from 208 subjects who were cognitively normal at enrollment and blood draw. Twenty-eight of the subjects subsequently developed MCI (n = 18) or AD (n = 10) over the follow-up period. Baseline measures of global cognition, memory, language fluency, and serum A?1–42 and the ratio of serum A?1–42/A?1–40 were significant pred...

Luis, Cheryl A.; Abdullah, Laila; Ait-ghezala, Ghania; Mouzon, Benoit; Keegan, Andrew P.; Crawford, Fiona; Mullan, Michael

2011-01-01

208

Hydration, cavities and volume in protein folding, aggregation and amyloid assembly  

International Nuclear Information System (INIS)

Differential hydration dictates various biological processes, including protein folding, ligand binding, macromolecular assembly, enzyme kinetics and signal transduction. If water is partially or totally removed (experimentally or in silico), the outcome of these processes can be significantly affected. The aggregation of proteins into amyloids or other aggregate forms also results in profound changes in hydration. High hydrostatic pressure is a unique tool to study hydration, as increases in water binding usually lead to decreases in volume. Pressure changes can favor the formation or disassembly of amyloids depending on the volume changes associated with protein folding and misfolding/aggregation. The packing and formation of cavities will also contribute to changes in volume, and therefore, to sensitivity to pressure. Therefore, the formation of water-excluding cavities is predicted to be an important event in folding and aggregation landscapes

209

Estrogen protects neuronal cells from amyloid beta-induced apoptosis via regulation of mitochondrial proteins and function  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Neurodegeneration in Alzheimer's disease is associated with increased apoptosis and parallels increased levels of amyloid beta, which can induce neuronal apoptosis. Estrogen exposure prior to neurotoxic insult of hippocampal neurons promotes neuronal defence and survival against neurodegenerative insults including amyloid beta. Although all underlying molecular mechanisms of amyloid beta neurotoxicity remain undetermined, mitochondrial dysfunction, including altered calcium homeostasis and Bcl-2 expression, are involved in neurodegenerative vulnerability. Results In this study, we investigated the mechanism of 17?-estradiol-induced prevention of amyloid beta-induced apoptosis of rat hippocampal neuronal cultures. Estradiol treatment prior to amyloid beta exposure significantly reduced the number of apoptotic neurons and the associated rise in resting intracellular calcium levels. Amyloid beta exposure provoked down regulation of a key antiapoptotic protein, Bcl-2, and resulted in mitochondrial translocation of Bax, a protein known to promote cell death, and subsequent release of cytochrome c. E2 pretreatment inhibited the amyloid beta-induced decrease in Bcl-2 expression, translocation of Bax to the mitochondria and subsequent release of cytochrome c. Further implicating the mitochondria as a target of estradiol action, in vivo estradiol treatment enhanced the respiratory function of whole brain mitochondria. In addition, estradiol pretreatment protected isolated mitochondria against calcium-induced loss of respiratory function. Conclusion Therefore, we propose that estradiol pretreatment protects against amyloid beta neurotoxicity by limiting mitochondrial dysfunction via activation of antiapoptotic mechanisms.

Iwamoto Sean

2006-11-01

210

Human neurons derived from a teratocarcinoma cell line express solely the 695-amino acid amyloid precursor protein and produce intracellular beta-amyloid or A4 peptides.  

OpenAIRE

The beta-amyloid or beta/A4 peptides that accumulate as filamentous aggregates in the extracellular space of Alzheimer disease (AD) brains are derived from one or more alternatively spliced amyloid precursor proteins (APPs). The more abundant APPs in the central nervous system are the 695-(APP695), 751- (APP751), and 770- (APP770) amino acid isoforms, and each could be the source of beta/A4 peptide that accumulates in the AD brain. It is plausible that altered metabolism of these APPs by cent...

Wertkin, A. M.; Turner, R. S.; Pleasure, S. J.; Golde, T. E.; Younkin, S. G.; Trojanowski, J. Q.; Lee, V. M.

1993-01-01

211

Characterization of the contributions of Hp-MMP 9 to the serum acute phase protein response of lipopolysaccharide challenged calves.  

Science.gov (United States)

BackgroundBovine respiratory disease (BRD) is a costly feature of modern cattle production. Early and accurate detection of BRD may prove useful in the successful management of this disease. The primary objective of the study was to define the time course of covalent complexes of neutrophil, haptoglobin (Hp) and matrix metalloproteinase 9 (Hp-MMP 9) in serum after intravenous lipopolysaccharide (LPS) in comparison to traditional markers. Our hypothesis was that serum concentrations of neutrophil Hp-MMP 9 provides information distinct from traditional acute phase protein markers. To characterize the neutrophil responses to lipopolysaccharide (E. coli; O111:B4; 2.5 ¿g/kg body weight), nine healthy, Jersey calves (65-82 days of age; 74.5¿±¿13.1 kg) were challenged and physiologic parameters, peripheral blood cell counts and serum cortisol (C), Hp-MMP 9, Hp, alpha1-acid glycoprotein (AGP), serum amyloid A (SAA)were obtained starting 24 hours before to 96 hours post-LPS challenge.ResultsPhysiologic parameters (temperature, pulse, respiratory rate) and attitude assessed at each time point indicated that LPS challenge resulted in rapid onset of depression, tachypnea, leukopenia, neutropenia and lymphopenia within 1 hour. Serum C concentrations were significantly increased by 1 hour post-LPS. Serum Hp-MMP 9 complexes were detectable in serum by 0.5 hours and peaked at 16 h, serum total Hp remained <10 ¿g/mL until 8 hours post LPS infusion and were significantly greater than baseline by 12 hours post-LPS infusion. Serum amyloid A concentrations increased significantly by 8 hours post LPS. Serum concentrations of AGP increased significantly by 16 hours post LPS. Serum concentrations of Hp, SAA and AGP remained significantly greater than baseline out to 96 hours post-LPS. The total systemic exposure to traditional makers is significantly greater than from Hp-MMP 9ConclusionUsing a well described model for acute phase protein responses, the data demonstrate that serum neutrophil Hp-MMP 9 complexes appear sooner and decline more rapidly than other acute phase proteins (APP). Since Hp-MMP9 is stored pre-formed, it provides information specifically addressing the LPS-induced activation of bovine neutrophils. Contributions of Hp-MMP 9 to the serum acute phase protein response may provide useful information, independent of hepatic responses, in diagnosis of acute inflammation. PMID:25358728

Hinds, Charles A; Niehaus, Andrew J; Premanandan, Christopher; Rajala-Schultz, Paivi J; Rings, Donald M; Lakritz, Jeffrey

2014-10-30

212

Molecular simulations of beta-amyloid protein near hydrated lipids (PECASE).  

Energy Technology Data Exchange (ETDEWEB)

We performed molecular dynamics simulations of beta-amyloid (A{beta}) protein and A{beta} fragment(31-42) in bulk water and near hydrated lipids to study the mechanism of neurotoxicity associated with the aggregation of the protein. We constructed full atomistic models using Cerius2 and ran simulations using LAMMPS. MD simulations with different conformations and positions of the protein fragment were performed. Thermodynamic properties were compared with previous literature and the results were analyzed. Longer simulations and data analyses based on the free energy profiles along the distance between the protein and the interface are ongoing.

Thompson, Aidan Patrick; Han, Kunwoo (Texas A& M University, College Station, TX); Ford, David M. (Texas A& M University, College Station, TX)

2005-12-01

213

Experimentally Derived Structural Constraints for Amyloid Fibrils of Wild-Type Transthyretin  

OpenAIRE

Transthyretin (TTR) is a largely ?-sheet serum protein responsible for transporting thyroxine and vitamin A. TTR is found in amyloid deposits of patients with senile systemic amyloidosis. TTR mutants lead to familial amyloidotic polyneuropathy and familial amyloid cardiomyopathy, with an earlier age of onset. Studies of amyloid fibrils of familial amyloidotic polyneuropathy mutant TTR suggest a structure similar to the native state with only a simple opening of a ?-strand-loop-strand region...

Bateman, David a; Tycko, Robert; Wickner, Reed b

2011-01-01

214

The Effects of Endogenous Non-Peptide Molecule Isatin and Hydrogen Peroxide on Proteomic Profiling of Rat Brain Amyloid-? Binding Proteins: Relevance to Alzheimer’s Disease?  

Directory of Open Access Journals (Sweden)

Full Text Available The amyloid-? peptide is considered as a key player in the development and progression of Alzheimer’s disease (AD. Although good evidence exists that amyloid-? accumulates inside cells, intracellular brain amyloid-binding proteins remain poorly characterized. Proteomic profiling of rat brain homogenates, performed in this study, resulted in identification of 89 individual intracellular amyloid-binding proteins, and approximately 25% of them were proteins that we had previously identified as specifically binding to isatin, an endogenous neuroprotector molecule. A significant proportion of the amyloid-binding proteins (more than 30% are differentially expressed or altered/oxidatively modified in AD patients. Incubation of brain homogenates with 70 µM hydrogen peroxide significantly influenced the profile of amyloid-? binding proteins and 0.1 mM isatin decreased the number of identified amyloid-? binding proteins both in control and hydrogen peroxide treated brain homogenates. The effects of hydrogen peroxide and isatin have been confirmed in optical biosensor experiments with purified glyceraldehyde-3-phosphate dehydrogenase, one of the known crucial amyloid-? binding proteins (also identified in this study. Data obtained suggest that isatin protects crucial intracellular protein targets against amyloid binding, and possibly favors intracellular degradation of this protein via preventing formation of amyloid-? oligomers described in the literature for some isatin derivatives.

Alexei E. Medvedev

2014-12-01

215

The Effects of Endogenous Non-Peptide Molecule Isatin and Hydrogen Peroxide on Proteomic Profiling of Rat Brain Amyloid-? Binding Proteins: Relevance to Alzheimer's Disease?  

Science.gov (United States)

The amyloid-? peptide is considered as a key player in the development and progression of Alzheimer's disease (AD). Although good evidence exists that amyloid-? accumulates inside cells, intracellular brain amyloid-binding proteins remain poorly characterized. Proteomic profiling of rat brain homogenates, performed in this study, resulted in identification of 89 individual intracellular amyloid-binding proteins, and approximately 25% of them were proteins that we had previously identified as specifically binding to isatin, an endogenous neuroprotector molecule. A significant proportion of the amyloid-binding proteins (more than 30%) are differentially expressed or altered/oxidatively modified in AD patients. Incubation of brain homogenates with 70 µM hydrogen peroxide significantly influenced the profile of amyloid-? binding proteins and 0.1 mM isatin decreased the number of identified amyloid-? binding proteins both in control and hydrogen peroxide treated brain homogenates. The effects of hydrogen peroxide and isatin have been confirmed in optical biosensor experiments with purified glyceraldehyde-3-phosphate dehydrogenase, one of the known crucial amyloid-? binding proteins (also identified in this study). Data obtained suggest that isatin protects crucial intracellular protein targets against amyloid binding, and possibly favors intracellular degradation of this protein via preventing formation of amyloid-? oligomers described in the literature for some isatin derivatives. PMID:25551598

Medvedev, Alexei E; Buneeva, Olga A; Kopylov, Arthur T; Gnedenko, Oksana V; Medvedeva, Marina V; Kozin, Sergey A; Ivanov, Alexis S; Zgoda, Victor G; Makarov, Alexander A

2014-01-01

216

Brain amyloid ? protein and memory disruption in Alzheimer’s disease  

Directory of Open Access Journals (Sweden)

Full Text Available Weiming XiaCenter for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USAAbstract: The development of amyloid-containing neuritic plaques is an invariable characteristic of Alzheimer’s diseases (AD. The conversion from monomeric amyloid ? protein (A? to oligomeric A? and finally neuritic plaques is highly dynamic. The specific Aß species that is correlated with disease severity remains to be discovered. Oligomeric A? has been detected in cultured cells, rodent and human brains, as well as human cerebrospinal fluid. Synthetic, cell, and brain derived A? oligomers have been found to inhibit hippocampal long-term potentiation (LTP and this effect can be suppressed by the blockage of A? oligomer formation. A large body of evidence suggests that A? oligomers inhibit N-methyl-D-aspartate receptor dependent LTP; additional receptors have also been found to elicit downstream pathways upon binding to A? oligomers. Amyloid antibodies and small molecular compounds that reduce brain A? levels and block A? oligomer formation are capable of reversing synaptic dysfunction and these approaches hold a promising therapeutic potential to rescue memory disruption.Keywords: Alzheimer, amyloid, oligomer, long-term potentiation, NMDA

Weiming Xia

2010-09-01

217

Amyloid accomplices and enforcers  

OpenAIRE

Amyloid-related diseases are often ascribed to protein “misfolding.” Yet in the absence of high-resolution structures for mature fibrils or intermediates, the connection between the mechanism of amyloid formation and protein folding remains tenuous. The simplistic view of amyloid fibrillogenesis as a homogeneous self-assembly process is being increasingly challenged by observations that amyloids interact with a variety of cofactors including metals, glycosaminoglycans, glycoproteins such ...

Alexandrescu, Andrei T.

2005-01-01

218

A canine model of Alzheimer's disease generated by overexpressing a mutated human amyloid precursor protein.  

Science.gov (United States)

Canines are considered the most authentic model for studying multifactorial human diseases, as these animals typically share a common environment with man. Somatic cell nuclear transfer (SCNT) technology along with genetic engineering of nuclear donor cells provides a unique opportunity for examining human diseases using transgenic canines. In the present study, we generated transgenic canines that overexpressed the human amyloid precursor protein (APP) gene containing well-characterized familial Alzheimer's disease (AD) mutations. We successfully obtained five out of six live puppies by SCNT. This was confirmed by observing the expression of green fluorescence protein in the body as a visual transgenic marker and the overexpression of the mutated APP gene in the brain. The transgenic canines developed AD-like symptoms, such as enlarged ventricles, an atrophied hippocampus, and ?-amyloid plaques in the brain. Thus, the transgenic canines we created can serve as a novel animal model for studying human AD. PMID:24481173

Lee, Geun-Shik; Jeong, Yeon Woo; Kim, Joung Joo; Park, Sun Woo; Ko, Kyeong Hee; Kang, Mina; Kim, Yu Kyung; Jung, Eui-Man; Moon, Changjong; Hyun, Sang Hwan; Hwang, Kyu-Chan; Kim, Nam-Hyung; Shin, Taeyoung; Jeung, Eui-Bae; Hwang, Woo Suk

2014-04-01

219

Bioluminescence imaging reveals inhibition of tumor cell proliferation by Alzheimer's amyloid ? protein  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Cancer and Alzheimer's disease (AD are two seemingly distinct diseases and rarely occur simultaneously in patients. To explore molecular determinants differentiating pathogenic routes towards AD or cancer, we investigate the role of amyloid ? protein (A? on multiple tumor cell lines that are stably expressing luciferase (human glioblastoma U87; human breast adenocarcinoma MDA-MB231; and mouse melanoma B16F. Results Quantification of the photons emitted from the MDA-MB231 or B16F cells revealed a significant inhibition of cell proliferation by the conditioning media (CM derived from amyloid precursor protein (APP over-expressing cells. The inhibition of U87 cells was observed only after the media was conditioned for longer than 2 days with APP over-expressing cells. Conclusion Our results suggest that A? plays an inhibitory role in tumor cell proliferation; this effect could depend on the type of tumor cells and amount of A?.

Zhao Hong

2009-06-01

220

Peripheral biomarkers in Autism: secreted amyloid precursor protein-? as a probable key player in early diagnosis  

OpenAIRE

Autism is a pervasive developmental disorder characterized by impairments in socialization and communication. There is currently no single molecular marker or laboratory tool capable of diagnosing autism at an early age. The purpose of this study is to explore the plausible use of peripheral biomarkers in the early diagnosis of autism via a sensitive ELISA. Here, we measured plasma secreted amyloid precursor protein alpha (sAPP-?) levels in autistic and aged-matched control blood samples and...

Bailey, Antoinette R.; Giunta, Brian N.; Obregon, Demian; Nikolic, William V.; Tian, Jun; Sanberg, Cyndy D.; Sutton, Danielle T.; Tan, Jun

2008-01-01

221

Exploring the Folding Pathways of Proteins through Energy Landscape Sampling: Application to Alzheimer's ?-Amyloid Peptide  

Directory of Open Access Journals (Sweden)

Full Text Available The determination of the folding mechanisms of proteins is critical to understand the topological change that can propagate Alzheimer's and prion diseases. The associated folding time scale generally precludes the use of molecular dynamics simulations. Here we present the details of the activation-relaxation simulations using the generic OPEP energy model. We illustrate the strengths of our approach by studying the folding of a dimer of the Alzheimer's ?-amyloid peptide.

Sebastien Santini

2003-09-01

222

Actions of ?-Amyloid Protein on Human Neurons Are Expressed through the Amylin Receptor  

OpenAIRE

Disruption of neurotoxic effects of amyloid ? protein (A?) is one of the major, but as yet elusive, goals in the treatment of Alzheimer's disease (AD). The amylin receptor, activated by a pancreatic polypeptide isolated from diabetic patients, is a putative target for the actions of A? in the brain. Here we show that in primary cultures of human fetal neurons (HFNs), AC253, an amylin receptor antagonist, blocks electrophysiological effects of A?. Pharmacological blockade of the amylin rec...

Jhamandas, Jack H.; Li, Zongming; Westaway, David; Yang, Jing; Jassar, Simran; Mactavish, David

2011-01-01

223

Bioluminescence Imaging Reveals Inhibition of Tumor Cell Proliferation by Alzheimer's Amyloid ? Protein  

OpenAIRE

Abstract Background Cancer and Alzheimer's disease (AD) are two seemingly distinct diseases and rarely occur simultaneously in patients. To explore molecular determinants differentiating pathogenic routes towards AD or cancer, we investigate the role of amyloid ? protein (A?) on multiple tumor cell lines that are stably expressing luciferase (human glioblastoma U87; human breast adenocarcinoma MDA-MB231; and mouse melanoma B16F). Results Quantification of the ...

Zhao Hong; Zhu Jinmin; Cui Kemi; Xu Xiaoyin; Brien Megan, O.; Wong Kelvin K; Kesari Santosh; Xia Weiming; Tc, Wong Stephen

2009-01-01

224

Chemokines, macrophage inflammatory protein-2 and stromal cell-derived factor-1?, suppress amyloid ?-induced neurotoxicity  

OpenAIRE

Alzheimer’s disease (AD) is characterized by a progressive cognitive decline and accumulation of neurotoxic oligomeric peptides amyloid-? (A?). Although the molecular events are not entirely known, it has become evident that inflammation, environmental and other risk factors may play a causal, disruptive and/or protective role in the development of AD. The present study investigated the ability of the chemokines, macrophage inflammatory protein-2 (MIP-2) and stromal cell-derived factor-1?...

Raman, Dayanidhi; Milatovic, Snjezana-zaja; Milatovic, Dejan; Splittgerber, Ryan; Fan, Guo-huang; Richmond, Ann

2011-01-01

225

Elemental analysis of human serum and serum protein fractions by thermal neutron activation  

International Nuclear Information System (INIS)

Some applications of thermal neutron activation for the determination of elemental contents in human serum and human serum protein fractions are presented. Firstly total serum is dealt with, secondly serum protein fractions obtained by gel filtration are described. A brief review on the role of (trace) elements in human health and disease and a compilation of literature data for elemental contents in human serum, as obtained by neutron activation techniques, are given. The most important sources of statistical and systematic errors are evaluated. Results for the contents of sodium, potassium, magnesium, bromine, iron, copper, zinc, selenium, rubidium, cesium and antimony in serum are given, with emphasis on control of accuracy and precision. The possible relation between selenium in blood and cancer occurrence in humans is discussed. The results of elemental analyses from cancer patients and from a patient receiving a cytostatic treatment are presented. A survey of literature results for the determination of protein-bound elemental contents in serum is presented. Subsequently, results from a study on the behaviour of elements during gel filtration are discussed. Gel-element and protein-element interactions are studied. Finally the protein-bound occurrence of trace elements in human serum is determined by gel filtration and neutron activation analysis. Results for both desalting and fractionation are given, for the elements bromine, copper, manganese, vanadium, selenium, zinc, rubidium, iron and iodine. (Auth.)

226

Change of dynamics of raft-model membrane induced by amyloid-? protein binding.  

Science.gov (United States)

While the steady-state existence in the size and shape of liquid-ordered microdomains in cell membranes, the so-called "lipid rafts", still remain the subject of debate, glycosphingolipid-cholesterol rich regions in plasma membranes have been considered to have a function as platforms for signaling and sorting. In addition, recent spectroscopic studies show that the interaction between monosialoganglioside and amyloid beta (A? protein promotes the transition of A? from the native structure to the cross-beta fold in amyloid aggregates. However, there is few evidence on the dynamics of "lipid rafts" membranes. As the neutron spin-echo (NSE) technique is well known to detect directly slow dynamics of membrane systems in situ, by the combination of NSE and small-angle X-ray scattering we have studied the effect of the interaction between raft-model membrane and amyloid A? proteins on the structure and dynamics of a large uni-lamellar vesicle (LUV) consisting of monosialoganglioside-cholesterol-phospholipid ternary mixtures as a model of lipid-raft membrane. We have found that the interaction between the A? proteins and the model membrane at the liquid crystal phase significantly suppresses a bending-diffusion motion with a minor effect on the LUV structure. The present results would suggest a possibility of non-receptor-mediated disorder in signaling through a modulation of a membrane dynamics induced by the association of amyloidogenic peptides on a plasma membrane. PMID:23852578

Hirai, Mitushiro; Kimura, Ryota; Takeuchi, Kazuki; Sugiyama, Masaaki; Kasahara, Kouji; Ohta, Noboru; Farago, Bela; Stadler, Andreas; Zaccai, Giuseppe

2013-07-01

227

Powerful beneficial effects of benfotiamine on cognitive impairment and beta-amyloid deposition in amyloid precursor protein/presenilin-1 transgenic mice.  

Science.gov (United States)

Reduction of glucose metabolism in brain is one of the main features of Alzheimer's disease. Thiamine (vitamin B1)-dependent processes are critical in glucose metabolism and have been found to be impaired in brains from patients with Alzheimer's disease. However, thiamine treatment exerts little beneficial effect in these patients. Here, we tested the effect of benfotiamine, a thiamine derivative with better bioavailability than thiamine, on cognitive impairment and pathology alterations in a mouse model of Alzheimer's disease, the amyloid precursor protein/presenilin-1 transgenic mouse. We show that after a chronic 8 week treatment, benfotiamine dose-dependently enhanced the spatial memory of amyloid precursor protein/presenilin-1 mice in the Morris water maze test. Furthermore, benfotiamine effectively reduced both amyloid plaque numbers and phosphorylated tau levels in cortical areas of the transgenic mice brains. Unexpectedly, these effects were not mimicked by another lipophilic thiamine derivative, fursultiamine, although both benfotiamine and fursultiamine were effective in increasing the levels of free thiamine in the brain. Most notably, benfotiamine, but not fursultiamine, significantly elevated the phosphorylation level of glycogen synthase kinase-3alpha and -3beta, and reduced their enzymatic activities in the amyloid precursor protein/presenilin-1 transgenic brain. Therefore, in the animal Alzheimer's disease model, benfotiamine appears to improve the cognitive function and reduce amyloid deposition via thiamine-independent mechanisms, which are likely to include the suppression of glycogen synthase kinase-3 activities. These results suggest that, unlike many other thiamine-related drugs, benfotiamine may be beneficial for clinical Alzheimer's disease treatment. PMID:20385653

Pan, Xiaoli; Gong, Neng; Zhao, Jing; Yu, Zhe; Gu, Fenghua; Chen, Jia; Sun, Xiaojing; Zhao, Lei; Yu, Meijing; Xu, Zhiru; Dong, Wenxin; Qin, Yan; Fei, Guoqiang; Zhong, Chunjiu; Xu, Tian-Le

2010-05-01

228

Brain amyloid in normal aging and cerebral amyloid angiopathy is antigenically related to Alzheimer's disease beta-protein.  

OpenAIRE

Amyloid deposition is a prominent feature of a number of brain disorders, in which amyloid fibrils are found within blood vessel walls, the neuropil (neuritic plaques), neurons (neurofibrillary tangles). These include Alzheimer's disease (AD), AD changes associated with Down's syndrome, neurologically asymptomatic amyloidosis, Parkinson dementia of Guam, hereditary cerebral hemorrhage with amyloidosis of Icelandic origin (HCHWA-I), hereditary cerebral hemorrhage with amyloidosis of Dutch orig...

Coria, F.; Castan?o, E. M.; Frangione, B.

1987-01-01

229

Unraveling the Early Events of Amyloid-? Protein (A? Aggregation: Techniques for the Determination of A? Aggregate Size  

Directory of Open Access Journals (Sweden)

Full Text Available The aggregation of proteins into insoluble amyloid fibrils coincides with the onset of numerous diseases. An array of techniques is available to study the different stages of the amyloid aggregation process. Recently, emphasis has been placed upon the analysis of oligomeric amyloid species, which have been hypothesized to play a key role in disease progression. This paper reviews techniques utilized to study aggregation of the amyloid-? protein (A? associated with Alzheimer’s disease. In particular, the review focuses on techniques that provide information about the size or quantity of oligomeric A? species formed during the early stages of aggregation, including native-PAGE, SDS-PAGE, Western blotting, capillary electrophoresis, mass spectrometry, fluorescence correlation spectroscopy, light scattering, size exclusion chromatography, centrifugation, enzyme-linked immunosorbent assay, and dot blotting.

N. Elizabeth Pryor

2012-03-01

230

Beta-Amyloid Precursor Protein (?APP) Processing in Alzheimer's Disease (AD) and Age-Related Macular Degeneration (AMD).  

Science.gov (United States)

Amyloid is a generic term for insoluble, often intensely hydrophobic, fibrous protein aggregates that arise from inappropriately folded versions of naturally-occurring polypeptides. The abnormal generation and accumulation of amyloid, often referred to as amyloidogenesis, has been associated with the immune and pro-inflammatory pathology of several progressive age-related diseases of the human central nervous system (CNS) including Alzheimer's disease (AD) and age-related macular degeneration (AMD). This 'research perspective' paper reviews some of the research history, biophysics, molecular-genetics and environmental factors concerning the contribution of amyloid beta (A?) peptides, derived from beta-amyloid precursor protein (?APP), to AD and AMD that suggests an extensive similarity in immune and inflammatory degenerative mechanisms between these two CNS diseases. PMID:25204496

Zhao, Yuhai; Bhattacharjee, Surjyadipta; Jones, Brandon M; Hill, James M; Clement, Christian; Sambamurti, Kumar; Dua, Prerna; Lukiw, Walter J

2014-09-10

231

Actions of ?-Amyloid Protein on Human Neurons Are Expressed through the Amylin Receptor  

Science.gov (United States)

Disruption of neurotoxic effects of amyloid ? protein (A?) is one of the major, but as yet elusive, goals in the treatment of Alzheimer's disease (AD). The amylin receptor, activated by a pancreatic polypeptide isolated from diabetic patients, is a putative target for the actions of A? in the brain. Here we show that in primary cultures of human fetal neurons (HFNs), AC253, an amylin receptor antagonist, blocks electrophysiological effects of A?. Pharmacological blockade of the amylin receptor or its down-regulation using siRNA in HFNs confers neuroprotection against oligomeric A?-induced caspase-dependent and caspase-independent apoptotic cell death. In transgenic mice (TgCRND8) that overexpress amyloid precursor protein, amylin receptor is up-regulated in specific brain regions that also demonstrate an elevated amyloid burden. The expression of A? actions through the amylin receptor in human neurons and temporospatial interrelationship of A? and the amylin receptor in an in vivo model of AD together provide a persuasive rationale for this receptor as a novel therapeutic target in the treatment of AD. PMID:21224052

Jhamandas, Jack H.; Li, Zongming; Westaway, David; Yang, Jing; Jassar, Simran; MacTavish, David

2011-01-01

232

Dietary (?)-epicatechin as a potent inhibitor of ??-secretase amyloid precursor protein processing?  

Science.gov (United States)

Flavonoids, a group of dietary polyphenols have been shown to possess cognitive health benefits. Epidemiologic evidence suggests that they could play a role in risk reduction in dementia. Amyloid precursor protein processing and the subsequent generation of amyloid beta (A?) are central to the pathogenesis of Alzheimer's disease, as soluble, oligomeric A? is thought to be the toxic species driving disease progression. We undertook an in vitro screen to identify flavonoids with bioactivity at ??-mediated amyloid precursor protein processing, which lead to identification of a number of flavonoids bioactive at 100 nM. Because of known bioavailability, we investigated the catechin family further and identified epigallocatechin and (?)-epicatechin as potent (nanomolar) inhibitors of amyloidogenic processing. Supporting this finding, we have shown reduced A? pathology and A? levels following short term, a 21-day oral delivery of (?)-epicatechin in 7-month-old TASTPM mice. Further, in vitro mechanistic studies suggest this is likely because of indirect BACE1 inhibition. Taken together, our results suggest that orally delivered (?)-epicatechin may be a potential prophylactic for Alzheimer's disease. PMID:25316600

Cox, Carla J.; Choudhry, Fahd; Peacey, Eleanor; Perkinton, Michael S.; Richardson, Jill C.; Howlett, David R.; Lichtenthaler, Stefan F.; Francis, Paul T.; Williams, Robert J.

2015-01-01

233

Dietary (-)-epicatechin as a potent inhibitor of ??-secretase amyloid precursor protein processing.  

Science.gov (United States)

Flavonoids, a group of dietary polyphenols have been shown to possess cognitive health benefits. Epidemiologic evidence suggests that they could play a role in risk reduction in dementia. Amyloid precursor protein processing and the subsequent generation of amyloid beta (A?) are central to the pathogenesis of Alzheimer's disease, as soluble, oligomeric A? is thought to be the toxic species driving disease progression. We undertook an in vitro screen to identify flavonoids with bioactivity at ??-mediated amyloid precursor protein processing, which lead to identification of a number of flavonoids bioactive at 100 nM. Because of known bioavailability, we investigated the catechin family further and identified epigallocatechin and (-)-epicatechin as potent (nanomolar) inhibitors of amyloidogenic processing. Supporting this finding, we have shown reduced A? pathology and A? levels following short term, a 21-day oral delivery of (-)-epicatechin in 7-month-old TASTPM mice. Further, in vitro mechanistic studies suggest this is likely because of indirect BACE1 inhibition. Taken together, our results suggest that orally delivered (-)-epicatechin may be a potential prophylactic for Alzheimer's disease. PMID:25316600

Cox, Carla J; Choudhry, Fahd; Peacey, Eleanor; Perkinton, Michael S; Richardson, Jill C; Howlett, David R; Lichtenthaler, Stefan F; Francis, Paul T; Williams, Robert J

2015-01-01

234

Cerebrospinal Fluid Amyloid ?40 Is Decreased in Cerebral Amyloid Angiopathy  

OpenAIRE

Cerebral amyloid angiopathy is caused by deposition of the amyloid ? protein in the cerebral vasculature. In analogy to previous observations in Alzheimer disease, we hypothesized that analysis of amyloid ?40 and ?42 proteins in the cerebrospinal fluid might serve as a molecular biomarker. We observed strongly decreased cerebrospinal fluid amyloid ?40 (p < 0.01 vs controls or Alzheimer disease) and amyloid ?42 concentrations (p < 0.001 vs controls and p < 0.05 vs Alzheimer disease) in ce...

Verbeek, Marcel M.; Kremer, Berry P. H.; Rikkert, Marcel Olde; Domburg, Peter H. M. F.; Skehan, Maureen E.; Greenberg, Steven M.

2009-01-01

235

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2006-01-01

236

Amyloid-? protein oligomerization and the importance of tetramers and dodecamers in the aetiology of Alzheimer’s disease  

OpenAIRE

In recent years, small protein oligomers have been implicated in the aetiology of a number of important amyloid diseases, such as type 2 diabetes, Parkinson's disease and Alzheimer's disease. As a consequence, research efforts are being directed away from traditional targets, such as amyloid plaques, and towards characterization of early oligomer states. Here we present a new analysis method, ion mobility coupled with mass spectrometry, for this challenging problem, which allows determination...

Bernstein, Sl; Dupuis, Nf; Lazo, Nd; Wyttenbach, T.; Condron, Mm; Bitan, G.; Teplow, Db; Shea, Je; Ruotolo, Bt; Robinson, Cv; Bowers, Mt

2009-01-01

237

Protein-induced photophysical changes to the amyloid indicator dye thioflavin T  

Energy Technology Data Exchange (ETDEWEB)

The small molecule thioflavin T (ThT) is a defining probe for the identification and mechanistic study of amyloid fiber formation. As such, ThT is fundamental to investigations of serious diseases such as Alzheimer's disease, Parkinson disease, and type II diabetes. For each disease, a different protein undergoes conformational conversion to a {beta}-sheet rich fiber. The fluorescence of ThT exhibits an increase in quantum yield upon binding these fibers. Despite its widespread use, the structural basis for binding specificity and for the changes to the photophysical properties of ThT remain poorly understood. Here, we report the co-crystal structures of ThT with two alternative states of {beta}-2 microglobulin ({beta}2m); one monomeric, the other an amyloid-like oligomer. In the latter, the dye intercalates between {beta}-sheets orthogonal to the {beta}-strands. Importantly, the fluorophore is bound in such a manner that a photophysically relevant torsion is limited to a range of angles generally associated with low, not high, quantum yield. Quantum mechanical assessment of the fluorophore shows the electronic distribution to be strongly stabilized by aromatic interactions with the protein. Monomeric {beta}2m gives little increase in ThT fluorescence despite showing three fluorophores, at two binding sites, in configurations generally associated with high quantum yield. Our efforts fundamentally extend existing understanding about the origins of amyloid-induced photophysical changes. Specifically, the {beta}-sheet interface that characterizes amyloid acts both sterically and electronically to stabilize the fluorophore's ground state electronic distribution. By preventing the fluorophore from adopting its preferred excited state configuration, nonradiative relaxation pathways are minimized and quantum yield is increased.

Wolfe, Leslie S.; Calabrese, Matthew F.; Nath, Abhinav; Blaho, Dorottya V.; Miranker, Andrew D.; Xiong, Yong (Yale)

2010-10-04

238

Protein-induced Photophysical Changes to the Amyloid Indicator Dye Thioflavin T  

Energy Technology Data Exchange (ETDEWEB)

The small molecule thioflavin T (ThT) is a defining probe for the identification and mechanistic study of amyloid fiber formation. As such, ThT is fundamental to investigations of serious diseases such as Alzheimer's disease, Parkinson disease, and type II diabetes. For each disease, a different protein undergoes conformational conversion to a {beta}-sheet rich fiber. The fluorescence of ThT exhibits an increase in quantum yield upon binding these fibers. Despite its widespread use, the structural basis for binding specificity and for the changes to the photophysical properties of ThT remain poorly understood. Here, we report the co-crystal structures of ThT with two alternative states of {beta}-2 microglobulin ({beta}2m); one monomeric, the other an amyloid-like oligomer. In the latter, the dye intercalates between {beta}-sheets orthogonal to the {beta}-strands. Importantly, the fluorophore is bound in such a manner that a photophysically relevant torsion is limited to a range of angles generally associated with low, not high, quantum yield. Quantum mechanical assessment of the fluorophore shows the electronic distribution to be strongly stabilized by aromatic interactions with the protein. Monomeric {beta}2m gives little increase in ThT fluorescence despite showing three fluorophores, at two binding sites, in configurations generally associated with high quantum yield. Our efforts fundamentally extend existing understanding about the origins of amyloid-induced photophysical changes. Specifically, the {beta}-sheet interface that characterizes amyloid acts both sterically and electronically to stabilize the fluorophore's ground state electronic distribution. By preventing the fluorophore from adopting its preferred excited state configuration, nonradiative relaxation pathways are minimized and quantum yield is increased.

L Wolfe; M Calabrese; A Nath; D Blaho; A Miranker; Y Xiong

2011-12-31

239

Cerebrospinal fluid amyloid beta and tau protein: Biomarkers for Alzheimer's disease  

OpenAIRE

Background/Aim. Introduction of acetylcholine esterase inhibitors as a symptomatic treatment of Alzheimer's disease (AD) has additionally highlighted the importance of diagnostic markers in cerebrospinal fluid (CSF) for early AD diagnosis: low level of 42 amino acid form of amyloid-? peptide (A?42), and levels of tau protein (T-tau) and phosphorylated tau protein (P-tau). The aim of this study was to diagnostic potential of CSF biomarkers T-tau, P-tau and A?42 as biochemical markers for AD...

Mandi? Gorana; Markovi? Ivanka; Ostoji? Marija; Stojkovi? Tanja; Misirli?-Den?i? Sonja; Živanovi?-Radni? Tatjana; Stefanovi? Rodoljub; Bumbaširevi? Marko; Stefanova Elka; Kosti? Vladimir

2008-01-01

240

Serum amyloid A stimulates macrophage foam cell formation via lectin-like oxidized low-density lipoprotein receptor 1 upregulation  

Energy Technology Data Exchange (ETDEWEB)

Highlights: ? SAA induced macrophage foam cell formation. ? SAA stimulated upregulation of lectin-like oxidized low-density lipoprotein receptor 1 (LOX1). ? SAA-induced LOX1 expression and foam cell formation is mediated by JNK/NF-?B signaling. ? HDL-conjugated SAA also stimulates foam cell formation via LOX1 upregulation. ? The finding reveals a novel mechanism of action of SAA in the pathogenesis of atherosclerosis. -- Abstract: Elevated levels of serum amyloid A (SAA) is a risk factor for cardiovascular diseases, however, the role of SAA in the pathophysiology of atherosclerosis remains unclear. Here we show that SAA induced macrophage foam cell formation. SAA-stimulated foam cell formation was mediated by c-jun N-terminal kinase (JNK) signaling. Moreover, both SAA and SAA-conjugated high density lipoprotein stimulated the expression of the important scavenger receptor lectin-like oxidized low-density lipoprotein receptor 1 (LOX1) via nuclear factor-?B (NF-?B). A LOX1 antagonist carrageenan significantly blocked SAA-induced foam cell formation, indicating that SAA promotes foam cell formation via LOX1 expression. Our findings therefore suggest that SAA stimulates foam cell formation via LOX1 induction, and thus likely contributes to atherogenesis.

Lee, Ha Young, E-mail: hayoung@skku.edu [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Kim, Sang Doo [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Baek, Suk-Hwan [Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Choi, Joon Hyuk [Department of Pathology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Cho, Kyung-Hyun [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Zabel, Brian A. [Palo Alto Institute for Research and Education, Veterans Affairs Hospital, Palo Alto, CA 94304 (United States); Bae, Yoe-Sik, E-mail: yoesik@skku.edu [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of)

2013-03-29

241

Serum amyloid A stimulates macrophage foam cell formation via lectin-like oxidized low-density lipoprotein receptor 1 upregulation  

International Nuclear Information System (INIS)

Highlights: ? SAA induced macrophage foam cell formation. ? SAA stimulated upregulation of lectin-like oxidized low-density lipoprotein receptor 1 (LOX1). ? SAA-induced LOX1 expression and foam cell formation is mediated by JNK/NF-?B signaling. ? HDL-conjugated SAA also stimulates foam cell formation via LOX1 upregulation. ? The finding reveals a novel mechanism of action of SAA in the pathogenesis of atherosclerosis. -- Abstract: Elevated levels of serum amyloid A (SAA) is a risk factor for cardiovascular diseases, however, the role of SAA in the pathophysiology of atherosclerosis remains unclear. Here we show that SAA induced macrophage foam cell formation. SAA-stimulated foam cell formation was mediated by c-jun N-terminal kinase (JNK) signaling. Moreover, both SAA and SAA-conjugated high density lipoprotein stimulated the expression of the important scavenger receptor lectin-like oxidized low-density lipoprotein receptor 1 (LOX1) via nuclear factor-?B (NF-?B). A LOX1 antagonist carrageenan significantly blocked SAA-induced foam cell formation, indicating that SAA promotes foam cell formation via LOX1 expression. Our findings therefore suggest that SAA stimulates foam cell formation via LOX1 induction, and thus likely contributes to atherogenesis

242

Nongradient blue native gel analysis of serum proteins and in-gel detection of serum esterase activities  

OpenAIRE

The objective of the present study was to analyze serum protein complexes and detect serum esterase activities using nongradient blue native polyacrylamide gel electrophoresis (BN-PAGE). For analysis of potential protein complexes, serum from rat was used. Results demonstrate that a total of 8 gel bands could be clearly distinguished after Coomassie blue staining, and serum albumin could be isolated nearly as a pure protein. Moreover, proteins in these bands were identified by electrospray ma...

Thangthaeng, Nopporn; Sumien, Nathalie; Forster, Michael J.; Shah, Ruchir A.; Yan, Liang-jun

2010-01-01

243

Tumor necrosis factor-? reduces beta-amyloid accumulation primarily by lowering cellular prion protein levels in a brain endothelial cell line.  

Science.gov (United States)

Disruption of beta-amyloid (A?) transport across the blood-brain barrier is thought to cause A? accumulation in the brain, thus leading to the development of Alzheimer's disease (AD). As AD patients show increased serum tumor necrosis factor-? (TNF?) levels, we examined the effect of TNF? on the function and expression of A? transport-related proteins including cellular prion protein (PrP(C)) in the mouse brain microvascular endothelial cell line MBEC4. TNF? decreased PrP(C) levels and intracellular radiolabeled A?. Similarly, anti-prion protein antibody also decreased radiolabeled A?. These results suggest that TNF? lowers PrP(C) levels, which in turn, reduces A? in the brain endothelium. PMID:25497018

Yasutaka, Yuki; Watanabe, Takuya; Nakashima, Akio; Matsumoto, Junichi; Futagami, Koujiro; Yamauchi, Atsushi; Kataoka, Yasufumi

2015-01-16

244

Rate of binding of antibiotics to canine serum protein.  

Science.gov (United States)

The time rates of binding of three antibiotics of similar chemical structure, each with differing degrees of protein binding, were determined. Cephaloridine, which is 10% bound by serum proteins, was bound at a more rapid rate than cephalothin, which is 40% bound by serum protein. Cefazolin, bound 80%, required for longest time period for maximum binding to occur. The rate of protein binding appears directly related to the total percentage bound. The data from this study indicate that prolonged rates of binding of highly protein-bound drugs may influence pharmacological studies. PMID:4840437

Waterman, N; Scharfenberger, L; Raff, M J

1974-03-01

245

The Hsp70/90 cochaperone, Sti1, suppresses proteotoxicity by regulating spatial quality control of amyloid-like proteins.  

Science.gov (United States)

Conformational diseases are associated with the conversion of normal proteins into aggregation-prone toxic conformers with structures similar to that of ?-amyloid. Spatial distribution of amyloid-like proteins into intracellular quality control centers can be beneficial, but cellular mechanisms for protective aggregation remain unclear. We used a high-copy suppressor screen in yeast to identify roles for the Hsp70 system in spatial organization of toxic polyglutamine-expanded Huntingtin (Huntingtin with 103Q glutamine stretch [Htt103Q]) into benign assemblies. Under toxic conditions, Htt103Q accumulates in unassembled states and speckled cytosolic foci. Subtle modulation of Sti1 activity reciprocally affects Htt toxicity and the packaging of Htt103Q into foci. Loss of Sti1 exacerbates Htt toxicity and hinders foci formation, whereas elevation of Sti1 suppresses Htt toxicity while organizing small Htt103Q foci into larger assemblies. Sti1 also suppresses cytotoxicity of the glutamine-rich yeast prion [RNQ+] while reorganizing speckled Rnq1-monomeric red fluorescent protein into distinct foci. Sti1-inducible foci are perinuclear and contain proteins that are bound by the amyloid indicator dye thioflavin-T. Sti1 is an Hsp70 cochaperone that regulates the spatial organization of amyloid-like proteins in the cytosol and thereby buffers proteotoxicity caused by amyloid-like proteins. PMID:24109600

Wolfe, Katie J; Ren, Hong Yu; Trepte, Philipp; Cyr, Douglas M

2013-12-01

246

Bacterial curli protein promotes the conversion of PAP248-286 into the amyloid SEVI: cross-seeding of dissimilar amyloid sequences  

Directory of Open Access Journals (Sweden)

Full Text Available Fragments of prostatic acid phosphatase (PAP248-286 in human semen dramatically increase HIV infection efficiency by increasing virus adhesion to target cells. PAP248-286 only enhances HIV infection in the form of amyloid aggregates termed SEVI (Semen Enhancer of Viral Infection, however monomeric PAP248-286 aggregates very slowly in isolation. It has therefore been suggested that SEVI fiber formation in vivo may be promoted by exogenous factors. We show here that a bacterially-produced extracellular amyloid (curli or Csg acts as a catalytic agent for SEVI formation from PAP248-286 at low concentrations in vitro, producing fibers that retain the ability to enhance HIV (Human Immunodeficiency Virus infection. Kinetic analysis of the cross-seeding effect shows an unusual pattern. Cross-seeding PAP248-286 with curli only moderately affects the nucleation rate while significantly enhancing the growth of fibers from existing nuclei. This pattern is in contrast to most previous observations of cross-seeding, which show cross-seeding partially bypasses the nucleation step but has little effect on fiber elongation. Seeding other amyloidogenic proteins (IAPP (islet amyloid polypeptide and A?1?40 with curli showed varied results. Curli cross-seeding decreased the lag-time of IAPP amyloid formation but strongly inhibited IAPP elongation. Curli cross-seeding exerted a complicated concentration dependent effect on A?1?40 fibrillogenesis kinetics. Combined, these results suggest that the interaction of amyloidogenic proteins with preformed fibers of a different type can take a variety of forms and is not limited to epitaxial nucleation between proteins of similar sequence. The ability of curli fibers to interact with proteins of dissimilar sequences suggests cross-seeding may be a more general phenomenon than previously supposed.

Kevin Hartman

2013-02-01

247

Differential serum protein markers and the clinical severity of asthma  

Directory of Open Access Journals (Sweden)

Full Text Available Norbert Meyer,1,2 Sarah Janine Nuss,1 Thomas Rothe,1 Alexander Siebenhüner,1 Cezmi A Akdis,2 Günter Menz11Hochgebirgsklinik Davos, Davos-Wolfgang, Switzerland; 2Swiss Institute of Allergy and Asthma Research (SIAF, Davos Platz, SwitzerlandBackground: Asthma is a heterogeneous disease characterized by different clinical phenotypes and the involvement of multiple inflammatory pathways. During airway inflammation, many cytokines and chemokines are released and some are detectable in the sera.Objective: Serum chemokines and cytokines, involved in airway inflammation in asthma patients, were investigated.Methods: A total of 191 asthma patients were classified by hierarchical cluster analysis, including the following parameters: forced expiratory volume in 1 second (FEV1, eosinophil cationic protein (ECP serum levels, blood eosinophils, Junipers asthma symptom score, and the change in FEV1, ECP serum levels, and blood eosinophils after 3 weeks of asthma therapy. Serum proteins were measured by multiplex analysis. Receiver operating characteristic (ROC curves were used to evaluate the validity of serum proteins for discriminating between asthma clusters.Results: Classification of asthma patients identified one cluster with high ECP serum levels, increased blood eosinophils, low FEV1 values, and good FEV1 improvement in response to asthma therapy (n=60 and one cluster with low ECP serum levels, low numbers of blood eosinophils, higher FEV1 values, and no FEV1 improvement in response to asthma therapy (n=131. Serum interleukin (IL-8, eotaxin, vascular endothelial growth factor (VEGF, cutaneous T-cell-attracting chemokine (CTACK, growth-related oncogene (GRO-?, and hepatocyte growth factor (HGF were significantly different between the two clusters of asthma patients. ROC analysis for serum proteins calculated a sensitivity of 55.9% and specificity of 75.8% for discriminating between them.Conclusion: Serum cytokine and chemokine levels might be predictors for the severity of asthmatic inflammation, asthma control, and response to therapy, and therefore might be useful for treatment optimization.Keywords: asthma, cluster, phenotype, serum cytokines

Meyer N

2014-04-01

248

Assessing novel prognostic serum biomarkers in advanced pancreatic cancer: the role of CYFRA 21-1, serum amyloid A, haptoglobin, and 25-OH vitamin D3.  

Science.gov (United States)

The present prospective single-center study investigated the prognostic role of novel serum biomarkers in advanced pancreatic cancer (PC). Patients (pts) with locally advanced or metastatic PC treated with first-line palliative chemotherapy were included. Among others, the serum markers CYFRA 21-1, haptoglobin, serum-amyloid A (SAA), and 25-OH vitamin D3 were determined at baseline and categorized by pre-defined cut-offs [median values (MV), upper limits of normal (ULN), lower limits of normal (LLN), or the natural logarithm (ln)] and correlated with overall survival (OS). Among the 59 pts included, pre-treatment CYFRA 21-1 levels showed a strong correlation with OS independent of the applied cut-off (MV 4.9 ng/ml-14.2 vs. 4.2 months, HR 0.18, p?=?0.001; ULN 3.3 ng/ml-14.2 vs. 4.4 months, HR 0.28, p?=?0.003; [ln] CYFRA 21-1-HR 0.77, p?=?0.013). Lower values of haptoglobin were additionally associated with an improvement in OS (categorized by LLN of 2.05 g/l-10.4 vs. 5.5 months, HR 0.46, p?=?0.023; [ln] haptoglobin-HR 0.51, p?=?0.036). Pts with baseline SAA values below the MV of 22 mg/l also had a prolonged OS (10.4 vs. 5.0 months, HR 0.47, p?=?0.036). For 25-OH vitamin D3 levels, no significant correlation with OS was found. In multivariate analyses, pre-treatment CYFRA 21-1 levels (categorized by MV-HR 0.15, p?=?0.032) as well as [ln] haptoglobin (HR 0.30, p?=?0.006) retained their independent prognostic significance for OS. CYFRA 21-1, haptoglobin, and SAA might provide useful prognostic information in advanced PC. An external multicenter validation of these results is necessary. PMID:25472579

Haas, Michael; Kern, Christoph; Kruger, Stephan; Michl, Marlies; Modest, Dominik P; Giessen, Clemens; Schulz, Christoph; von Einem, Jobst C; Ormanns, Steffen; Laubender, Rüdiger P; Holdenrieder, Stefan; Heinemann, Volker; Boeck, Stefan

2014-12-01

249

The first molluscan acute phase serum amyloid A (A-SAA) identified from oyster Crassostrea hongkongensis: molecular cloning and functional characterization.  

Science.gov (United States)

Serum amyloid A (SAA), a major evolutionarily conserved acute-phase protein, participates in many biological processes in eukaryotic cells, including innate immunity. However, little information regarding the relationship between SAA and innate immunity in mollusks is currently available. In this report, the first bivalve SAA (referred to as ChSAA) gene was identified and characterized from the Hong Kong oyster Crassostrea hongkongensis. Its full-length cDNA is 623 bp, including a 5'-UTR of 147 bp, a 3'-UTR of 56 bp containing a poly(A) tail and an open reading frame (ORF) of 420 bp that encodes a polypeptide of 139 amino acids. The predicted amino acid sequence of ChSAA comprises characteristic motifs of the SAA family, including a typical signal peptide and a conserved SAA domain. Comparison and phylogenetic analyses suggested that ChSAA shares a high identity to known acute-phase SAA proteins (A-SAAs). In addition, quantitative real-time PCR analysis revealed that ChSAA is constitutively expressed in all tissues examined, with the highest expression level in the mantle, and that its expression was acutely and significantly up-regulated in hemocytes following challenge by Vibrio alginolyticus (G(-)), Staphylococcus haemolyticus (G(+)) or Saccharomyces cerevisiae (fungus). Furthermore, over-expression of ChSAA via transfection with a ChSAA expression vector led to significantly increased NF-?B activity in HEK293T cells. These results suggest that ChSAA is likely to constitute a member of the A-SAA family involved in anti-pathogen responses in C. hongkongensis. PMID:24859593

Qu, Fufa; Xiang, Zhiming; Yu, Ziniu

2014-08-01

250

Acute phase serum proteins in diabetic retinopathy  

Directory of Open Access Journals (Sweden)

Full Text Available The serum concentration of various acute phase reactants were studied in patients with non-insulin dependent diabetes mellitus with and without retinopathy and in control subjects. The serum levels of haptoglobin was elevated in diabetics with retinopathy and the levels were highest in those with proliferative diabetic retinopathy. The levels of serum albumin, alpha-1 acid glycoprotein, alpha-1 antitrypsin and caeruloplasmin were not significantly different between the patients with retinopathy and controls. Haptoglobin increases serum viscosity and this could be the mechanism by which it plays a role in pathogenesis of diabetic retinopathy. These preliminary observations need to be confirmed by studies based on larger number of patients. Longitudinal studies on acute phase reactants in various stages of development of diabetic retinopathy would also provide valuable information.

Rema M

1996-01-01

251

Involvement of ?-site APP cleaving enzyme 1 (BACE1) in amyloid precursor protein-mediated enhancement of memory and activity-dependent synaptic plasticity  

OpenAIRE

The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid-? protein (A?), which forms amyloid plaques in Alzheimer's disease (AD), secreted APP? (sAPP?) which enhances memory, and the APP intracellular domain (AICD), which has been implicated in the regulation of gene transcription and calcium signaling. The ?-site APP cleaving enzyme 1 (BACE1) cleaves APP in an activity-dependent manner to form A?, AICD, and secreted APP?...

Ma, Huifang; Lesne?, Sylvain; Kotilinek, Linda; Steidl-nichols, Jill V.; Sherman, Mathew; Younkin, Linda; Younkin, Steven; Forster, Colleen; Sergeant, Nicolas; Delacourte, Andre?; Vassar, Robert; Citron, Martin; Kofuji, Paulo; Boland, Linda M.; Ashe, Karen H.

2007-01-01

252

TSH binding proteins in rat and human serum  

International Nuclear Information System (INIS)

When serum of hypothyroid rats was fractionated on a Sephadex G-100 column, most of the immunoreactive TSH was found as a front running peak, together with the high molecular weight serum proteins. Similarly, a rTSH preparation (10 mU), chromatographed in the presence of 1 ml of normal rat serum also migrated at the front, however, when a high load of TSH (4.4 U) was added to 1 ml of serum, two immunoreactive peaks were found, suggesting the saturation of the front running fraction. Immunoelectrophoresis and autoradiography of rat or human sera containing the respective 125I-labelled TSHs showed binding of the labelled TSH to IgG, alpha-2-macroglobulin, and to a third unidentified protein, migrating near the albumin line. In order to determine if the bound TSH is biologically active, the high molecular weight protein fraction was separated from hypothyroid rat serum by 45% ammonium sulphate precipitation. Immunoreactivity was determined by RIA and the biological activity was determined, in vitro, by the stimulation of 99Tc uptake by FRTL-5 cells. The 45% ammonium sulphate precipitate contained almost all of the immunoreactivity and the bioactivity of the TSH of whole serum. These results indicate that: a) The endogenous circulating TSH in the hypothyroid rat exists mainly in a protein-bound form and this protein-bound TSH contains most of the hormonal bioactivity of the serum. b) Exogenous TSH binds to serum proteins in euthyroid and hypothyroid rum proteins in euthyroid and hypothyroid rats and in humans. There are three protein fractions in these sera that bind TSH, one of which is an immunoglobulin. The occurence of TSH binding immunoglobulins may involve autoimmune mechanisms. (author)

253

Serum Copper and Plasma Protein Status in Normal Pregnancy  

OpenAIRE

AbstractBackground: Gradual alteration of serum copper and some plasma protein levels may occur with advancement of pregnancy, which is associated with increased maternal and infant morbidity and mortality.Objective: To observe serum copper and plasma protein levels in normal pregnant women of different trimesters in order to find out their nutritional status.Methods: This cross sectional study was carried out in the Department of Physiology, Sir Salimullah Medical College (SSMC), Dhaka, betw...

Nushrat Noor, Nasim Jahan

2012-01-01

254

Cysteine 27 Variant of the ?-Opioid Receptor Affects Amyloid Precursor Protein Processing through Altered Endocytic Trafficking ?  

Science.gov (United States)

Agonist-induced activation of the ?-opioid receptor (?OR) was recently shown to augment ?- and ?-secretase activities, which increased the production of ?-amyloid peptide (A?), known to accumulate in the brain tissues of Alzheimer's disease (AD) patients. Previously, the ?OR variant with a phenylalanine at position 27 (?OR-Phe27) exhibited more efficient receptor maturation and higher stability at the cell surface than did the less common cysteine (?OR-Cys27) variant. For this study, we expressed these variants in human SH-SY5Y and HEK293 cells expressing exogenous or endogenous amyloid precursor protein (APP) and assessed the effects on APP processing. Expression of ?OR-Cys27, but not ?OR-Phe27, resulted in a robust accumulation of the APP C83 C-terminal fragment and the APP intracellular domain, while the total soluble APP and, particularly, the ?-amyloid 40 levels were decreased. These changes upon ?OR-Cys27 expression coincided with decreased localization of APP C-terminal fragments in late endosomes and lysosomes. Importantly, a long-term treatment with a subset of ?OR-specific ligands or a c-Src tyrosine kinase inhibitor suppressed the ?OR-Cys27-induced APP phenotype. These data suggest that an increased constitutive internalization and/or concurrent signaling of the ?OR-Cys27 variant affects APP processing through altered endocytic trafficking of APP. PMID:21464208

Sarajärvi, Timo; Tuusa, Jussi T.; Haapasalo, Annakaisa; Lackman, Jarkko J.; Sormunen, Raija; Helisalmi, Seppo; Roehr, Johannes T.; Parrado, Antonio R.; Mäkinen, Petra; Bertram, Lars; Soininen, Hilkka; Tanzi, Rudolph E.; Petäjä-Repo, Ulla E.; Hiltunen, Mikko

2011-01-01

255

Palmitoylation and amyloid fibril formation of lung surfactant protein C  

OpenAIRE

Lung surfactant is a mixture of lipids and a few proteins, of which surfactant proteins (SP)-B and SP-C are lipophilic. Surfactant is essential for the reduction of surface tension at the alveolar air/liquid interface. The extremely hydrophobic SP-C is a 35-residue transmembraneous [alpha]-helical peptide containing a poly-Val stretch and two palmitoylated Cys residues. In this thesis the structural and functional importance of the SP-C palmitoyl groups and the poly-Val heli...

Gustafsson, Magnus

2000-01-01

256

Plasmodium falciparum merozoite surface protein 2 is unstructured and forms amyloid-like fibrils.  

Science.gov (United States)

Several merozoite surface proteins are being assessed as potential components of a vaccine against Plasmodium falciparum, the cause of the most serious form of human malaria. One of these proteins, merozoite surface protein 2 (MSP2), is unusually hydrophilic and contains tandem sequence repeats, characteristics of intrinsically unstructured proteins. A range of physicochemical studies has confirmed that recombinant forms of MSP2 are largely unstructured. Both dimorphic types of MSP2 (3D7 and FC27) are equivalently extended in solution and form amyloid-like fibrils although with different kinetics and structural characteristics. These fibrils have a regular underlying beta-sheet structure and both fibril types stain with Congo Red, but only the FC27 fibrils stain with Thioflavin T. 3D7 MSP2 fibrils seeded the growth of fibrils from 3D7 or FC27 MSP2 monomer indicating the involvement of a conserved region of MSP2 in fibril formation. Consistent with this, digestion of fibrils with proteinase K generated resistant peptides, which included the N-terminal conserved region of MSP2. A monoclonal antibody that reacted preferentially with monomeric recombinant MSP2 did not react with the antigen in situ on the merozoite surface. Glutaraldehyde cross-linking of infected erythrocytes generated MSP2 oligomers similar to those formed by polymeric recombinant MSP2. We conclude that MSP2 oligomers containing intermolecular beta-strand interactions similar to those in amyloid fibrils may be a component of the fibrillar surface coat on P. falciparum merozoites. PMID:19450733

Adda, Christopher G; Murphy, Vince J; Sunde, Margaret; Waddington, Lynne J; Schloegel, Jesse; Talbo, Gert H; Vingas, Kleo; Kienzle, Vivian; Masciantonio, Rosella; Howlett, Geoffrey J; Hodder, Anthony N; Foley, Michael; Anders, Robin F

2009-08-01

257

Senile aortic amyloid. A third distinctive type of age-related cardiovascular amyloid.  

OpenAIRE

Aortic tissues from 22 elderly patients were analyzed by Congo red staining for amyloid deposits. All samples contained amyloid, which was resistant to the potassium permanganate reaction. Tryptophan was present in all amyloid deposits. The amyloid failed to react with antiserums to amyloid fibril protein ASc1 or human prealbumin, proteins previous demonstrated in generalized senile cardiac amyloid. It also differed from age-related isolated atrial amyloid, which has been shown to lack trypto...

Cornwell, G. G.; Westermark, P.; Murdoch, W.; Pitka?nen, P.

1982-01-01

258

Endolysosome involvement in HIV-1 transactivator protein-induced neuronal amyloid beta production.  

Science.gov (United States)

The increased life expectancy of people living with HIV-1/AIDS is accompanied by increased prevalence of HIV-1-associated neurocognitive disorder. As well, these individuals are increasingly experiencing Alzheimer's disease (AD)-like neurocognitive problems and neuropathological features such as increased deposition of amyloid beta (A?) protein. Findings that A? production occurs largely in endolysosomes, that HIV-1 transactivator protein (Tat) disrupts endolysosome function-an early pathological feature of AD-and that HIV-1 Tat can increase A? levels prompted us to test the hypothesis that endolysosome dysfunction is associated with HIV-1 Tat-induced increases in neuronal A? generation. Using primary cultured rat hippocampal neurons, we found that treatment with HIV-1 Tat caused such morphological changes as enlargement of endolysosomes identified with LysoTracker dye and such functional changes as elevated endolysosome pH measured ratiometrically with LysoSensor dye. The HIV-1 Tat-induced changes in endolysosome function preceded temporally HIV-1 Tat-induced increases in A? generation measured using enzyme-linked immunosorbent assay. In addition, we demonstrated that HIV-1 Tat increased endolysosome accumulation of A? precursor protein and A? identified using immunostaining with 4G8 antibodies. Furthermore, we demonstrated that treatment of neurons with HIV-1 Tat increased endolysosome accumulation of beta amyloid-converting enzyme, the rate-limiting enzymatic step for A? production, and enhanced beta amyloid-converting enzyme activity. Together, our findings suggest that HIV-1 Tat increases neuronal A? generation and thereby contributes to the development of AD-like pathology in HIV-1-infected individuals by disturbing endolysosome structure and function. PMID:23673310

Chen, Xuesong; Hui, Liang; Geiger, Nicholas H; Haughey, Norman J; Geiger, Jonathan D

2013-10-01

259

The Histidine Composition of the Amyloid-? Domain, but not the E1 Copper Binding Domain, Modulates ?-Secretase Processing of Amyloid-? Protein Precursor in Alzheimer's Disease.  

Science.gov (United States)

Amyloid-? protein precursor (A?PP) proteolysis by ?- and ?-secretases generates neurotoxic amyloid-? (A?)-peptides in Alzheimer's disease (AD). We have investigated the role of histidine residues within the extracellular E1 copper binding and A? domains of A?PP in its proteolysis. By stably expressing histidine to alanine A?PP mutant constructs in SH-SY5Y cells, we show that mutations in the E1 copper binding domain had no impact on ?- or ?-secretase processing. Mutation of histidine 14 within the A?-domain specifically down-regulated ?-secretase processing without impacting on non-amyloidogenic proteolysis. Understanding how histidine 14 participates in A?PP proteolysis may reveal new intervention points for AD treatments. PMID:25171714

Gough, Mallory; Blanthorn-Hazell, Sophee; Parkin, Edward T

2015-01-01

260

Biochemical indicators of vitamin A deficiency: Serum retinol and serum retinol binding protein  

OpenAIRE

Two biochemical indicators are currently recommended for determining whether vitamin A deficiency (VAD) is a public health problem: serum retinol and serum retinol-binding protein (RBP). After consideration of 40 data sets and the original rationale for previously proposed cut-offs, a cut-off for serum retinol concentration was proposed at <0.70 mumol/L (20 mug/dL) in greater than or equal to15% of the sampled population. This cut-off should be applied to a representative group of preschool a...

Pee, S.; Dary, O.

2002-01-01

261

Serum Amyloid A Promotes Lung Neutrophilia by Increasing IL-17A Levels in the Mucosa and ?? T Cells  

Science.gov (United States)

Rationale: Neutrophilic inflammation is an important pathologic feature of chronic obstructive pulmonary disease (COPD) and infectious exacerbations of COPD. Serum amyloid A (SAA) promotes neutrophilic inflammation by its interaction with lung mucosal ALX/FPR2 receptors. However, little is known about how this endogenous mediator regulates IL-17A immunity. Objectives: To determine whether SAA causes neutrophilic inflammation by IL-17A–dependent mechanisms. Methods: The relationship between SAA and neutrophils was investigated in lung sections from patients with COPD and a chronic mouse model of SAA exposure. A neutralizing antibody to IL-17A was used to block SAA responses in vivo, and a cell-sorting strategy was used to identify cellular sources. Measurements and Main Results: SAA mRNA expression was positively associated with tissue neutrophils in COPD (P < 0.05). SAA predominately promoted expression of the TH17 polarizing cytokine IL-6, which was opposed by 15-epi-lipoxin A4, a counter-regulatory mediator, and ALX/FPR2 ligand. SAA-induced inflammation was markedly reduced by a neutralizing antibody to IL-17A in vivo. Cellular sources of IL-17A induced by SAA include CD4+ T cells, ?? T cells, and an Epcam+CD45? population enriched for epithelial cells. SAA promotes expression of IL-17A in ?? T cells and this innate cell proportionally expressed higher levels of IL-17A transcript than CD4+ T cells or epithelial cells. Conclusions: The SAA–IL-17A axis represents an important innate defense network that may underlie persistent neutrophilic airway inflammation in COPD and modulating the ALX/FPR2 receptor represents a novel approach to targeting aberrant IL-17A–mediated lung immunity. PMID:23627303

Anthony, Desiree; Seow, Huei Jiunn; Uddin, Mohib; Thompson, Michelle; Dousha, Lovisa; Vlahos, Ross; Irving, Louis B.; Levy, Bruce D.; Anderson, Gary P.

2013-01-01

262

Neuroinflammation in Lyme neuroborreliosis affects amyloid metabolism  

OpenAIRE

Abstract Background The metabolism of amyloid precursor protein (APP) and ?-amyloid (A?) is widely studied in Alzheimer's disease, where A? deposition and plaque development are essential components of the pathogenesis. However, the physiological role of amyloid in the adult nervous system remains largely unknown. We have previously found altered cerebral amyloid metabolism in other neuroinflammatory conditions. To further elucidate this, we investigated amyloid metabolism...

Anckarsäter Henrik; Blennow Kaj; Bremell Daniel; Anckarsäter Rolf; Mattsson Niklas; Zetterberg Henrik; Hagberg Lars

2010-01-01

263

Detection of human serum proteins using Raman and SERS spectroscopy  

Science.gov (United States)

The use of normal Raman (NR) spectroscopy and surface enhanced Raman scattering (SERS) spectroscopy to analyze the biochemical information of human serum proteins and hence distinguish between normal and primary hepatic carcinoma (PHC) serum samples was investigated. The serum samples were obtained from patients who were clinically diagnosed with PHC (n=20) and healthy volunteers (n=20). All spectra were collected in the spectral range of 400-1800 cm-1 and analyzed through the multivariate statistical methods of principal component analysis (PCA). The results showed that both NR and SERS combined with PCA had good performance in distinguishing the human serum proteins between PHC patients and healthy volunteers with high sensitivity and specificity of 100%. And we can get more detail information of component and conformation of human serum proteins by considering NR and SERS spectrum. Our results support the concept again that serum protein Raman and SERS spectroscopy combined with PCA analysis both can become noninvasive and rapid diagnostic tools to detect the primary hepatic carcinoma.

Ruan, Qiuyong; Liao, Fadian; Lin, Juqiang; Liu, Nenrong; Lin, Jinyong; Zeng, Yongyi; Li, Ling; Huang, Zufang; Chen, Rong

2014-09-01

264

A quantitative method for detecting deposits of amyloid A protein in aspirated fat tissue of patients with arthritis  

OpenAIRE

OBJECTIVE—To describe a new, quantitative, and reproducible method for detecting deposits of amyloid A protein in aspirated fat tissue and to compare it with smears stained with Congo red.?METHODS—After extraction of at least 30 mg of abdominal fat tissue in guanidine, the amyloid A protein concentration was measured by a monoclonal antibody-based sandwich ELISA.?RESULTS—The concentrations in 24 patients with arthritis and AA amyloidosis (median 236, range 1.1-8530 ng/mg tissue) ...

Hazenberg, B.; Limburg, P.; Bijzet, J.; Rijswijk, M. H.

1999-01-01

265

Serum amyloid A (SAA) as a biomarker of chronic infection due to boat strike trauma in a free-ranging Florida manatee (Trichechus manatus latirostris) with incidental polycystic kidneys  

Science.gov (United States)

Watercraft-related trauma is the predominant cause of human-induced mortality in manatees (Trichechus manatus latirostris), a federal- and state-listed endangered species. Pyothorax (documented in this case report) and other secondary infections are common sequelae of inhalation of water and the open wounds caused by boat propellers. These secondary infections can lead to the demise of the animal weeks to months after the traumatic incident when external wounds have healed. Diagnosis of underlying disease on physical examination during capture and restraint can be difficult. Acute phase proteins, including serum amyloid A, fibrinogen, and albumin can be used to diagnose inflammatory disease in manatees and improve quality of medical care and husbandry. We also provide the first report of polycystic kidneys in Sirenians.

Harr, Kendal E.; Rember, Renee; Ginn, Pamela E.; Lightsey, Jessica; Keller, Martha; Reid, James; Bonde, Robert K.

2011-01-01

266

Immunoglobulin light chains, glycosaminoglycans and amyloid.  

Energy Technology Data Exchange (ETDEWEB)

Immunoglobulin light chains are the precursor proteins for fibrils that are formed during primary amyloidosis and in amyloidosis associated with multiple myeloma. As found for the approximately 20 currently described forms of focal, localized, or systemic amyloidoses, light chain-related fibrils extracted from physiological deposits are invariably associated with glycosaminoglycans, predominantly heparan sulfate. Other amyloid-related proteins are either structurally normal, such as g2-microglobulin and islet amyloid polypeptide, fragments of normal proteins such as serum amyloid A protein or the precursor protein of the g peptide involved in Alzheimer's disease, or are inherited forms of single amino acid variants of a normal protein such as found in the familial forms of amyloid associated with transthyretin. In contrast, the primary structures of light chains involved in fibril formation exhibit extensive mutational diversity rendering some proteins highly amyloidogenic and others non-pathological. The interactions between light chains and glycosaminoglycans are also affected by amino acid variation and may influence the clinical course of disease by enhancing fibril stability and contributing to resistance to protease degradation. Relatively little is currently known about the mechanisms by which glycosaminoglycans interact with light chains and light-chain fibrils. It is probable that future studies of this uniquely diverse family of proteins will continue o shed light on the processes of amyloidosis, and contribute as well to a greater understanding of the normal physiological roles of glycosaminoglycans.

Stevens, F. J.; Kisilevsky, R.; Biosciences Division; Queen' s Univ.

2000-03-01

267

Amyloid-clearing proteins and their epigenetic regulation as a therapeutic target in Alzheimer’s disease  

Directory of Open Access Journals (Sweden)

Full Text Available Abnormal elevation of amyloid ?-peptide (A? levels in the brain is the primary trigger for neuronal cell death specific to Alzheimer’s disease (AD. It is now evident that A? levels in the brain are manipulable due to a dynamic equilibrium between its production from the amyloid precursor protein (APP and removal by amyloid clearance proteins. Clearance can be either enzymic or non-enzymic (binding/transport proteins. Intriguingly several of the main amyloid-degrading enzymes (ADEs are members of the M13 peptidase family (neprilysin (NEP, NEP2 and the endothelin converting enzymes (ECE-1 and -2. A distinct metallopeptidase, insulin-degrading enzyme (IDE, also contributes to A? degradation in the brain. The ADE family currently embraces more than 20 members, both membrane-bound and soluble, and of differing cellular locations. NEP plays an important role in brain function terminating neuropeptide signals. Its decrease in specific brain areas with age or after hypoxia, ischaemia or stroke contribute significantly to the development of AD pathology. The recently discovered mechanism of epigenetic regulation of NEP (and other genes by the APP intracellular domain (AICD and its dependence on the cell type and APP isoform expression suggest possibilities for selective manipulation of NEP gene expression in neuronal cells. We have also observed that another amyloid-clearing protein, namely transthyretin (TTR, is also regulated in the neuronal cell by a mechanism similar to NEP. Dependence of amyloid clearance proteins on histone deacetylases and the ability of HDAC inhibitors to up-regulate their expression in the brain opens new avenues for developing preventive strategies in AD.

Anthony J Turner

2014-09-01

268

Amyloid-clearing proteins and their epigenetic regulation as a therapeutic target in Alzheimer’s disease  

Science.gov (United States)

Abnormal elevation of amyloid ?-peptide (A?) levels in the brain is the primary trigger for neuronal cell death specific to Alzheimer’s disease (AD). It is now evident that A? levels in the brain are manipulable due to a dynamic equilibrium between its production from the amyloid precursor protein (APP) and removal by amyloid clearance proteins. Clearance can be either enzymic or non-enzymic (binding/transport proteins). Intriguingly several of the main amyloid-degrading enzymes (ADEs) are members of the M13 peptidase family (neprilysin (NEP), NEP2 and the endothelin converting enzymes (ECE-1 and -2)). A distinct metallopeptidase, insulin-degrading enzyme (IDE), also contributes to A? degradation in the brain. The ADE family currently embraces more than 20 members, both membrane-bound and soluble, and of differing cellular locations. NEP plays an important role in brain function terminating neuropeptide signals. Its decrease in specific brain areas with age or after hypoxia, ischaemia or stroke contribute significantly to the development of AD pathology. The recently discovered mechanism of epigenetic regulation of NEP (and other genes) by the APP intracellular domain (AICD) and its dependence on the cell type and APP isoform expression suggest possibilities for selective manipulation of NEP gene expression in neuronal cells. We have also observed that another amyloid-clearing protein, namely transthyretin (TTR), is also regulated in the neuronal cell by a mechanism similar to NEP. Dependence of amyloid clearance proteins on histone deacetylases and the ability of HDAC inhibitors to up-regulate their expression in the brain opens new avenues for developing preventive strategies in AD. PMID:25278875

Nalivaeva, Natalia N.; Belyaev, Nikolai D.; Kerridge, Caroline; Turner, Anthony J.

2014-01-01

269

Magnetic nanoparticles-serum proteins bioconjugates for binding of irinotecan.  

Science.gov (United States)

The binding of irinotecan to serum proteins (hemoglobin, globulin and human serum albumin) was studied on the surface of epoxide modified superparamagnetic iron oxide nanoparticles (GPTS-SPIONs), which were synthesized by the coprecipitation of ferrous and ferric salts with NH4OH and then modified with [3-(2,3-epoxypropoxy)propyl] trimethoxy silane (GPTS) to obtain functional epoxide groups on the SPIONs' surface. Results were compared to find an alternative as drug carries system. Data showed that binding amount of human serum albumin (HSA), globulin (Glb) and hemoglobin (Hb) found to be as 44, 21.2 and 32.6?g per 20mg of GPTS modified SPIONs, respectively. The thermal behavior of the serum protein-Ir interaction on GPTS-SPIONs was also studied by using thermo gravimetric analysis (TGA) technique and then the kinetic parameters for the thermal decomposition were determined using Horowitz-Metzger method. PMID:25445689

Tamyurek, Ecem; Maltas, Esra; Bas, Salih Zeki; Ozmen, Mustafa; Yildiz, Salih

2015-02-01

270

Differential expression and redox proteomics analyses of an Alzheimer disease transgenic mouse model: effects of the amyloid-? peptide of amyloid precursor protein.  

Science.gov (United States)

Among the pathological factors known to be associated with Alzheimer disease (AD), oxidative stress induced by the amyloid-? peptide (A?) has been demonstrated to play a key role in human brain and animal models of AD. Recently, we reported elevated levels of oxidative damage in the brain of a transgenic (Tg) AD mouse model with Swedish and Indiana familial AD mutations in human amyloid precursor protein (APP) [PDAPP mice, line J20], as evidenced by increased levels of protein carbonyls, 3-nitrotyrosine, and protein-bound 4-hydroxy-2-nonenal. This oxidative damage was dependent on the methionine 35 residue within the A? peptide. Further insight into the molecular pathways affected in this Tg model of AD may be gained with discovery-based proteomics studies; therefore, two-dimensional gel-based expression proteomics was performed to compare differences in brain protein levels of J20 Tg mice with non-transgenic (NTg) littermate controls. Based on our studies, we identified six proteins that had significantly increased levels in J20 Tg relative to NTg mice: calcineurin subunit B type 1, ? GDP-dissociation inhibitor 1, T-complex protein 1 subunit ? A, ?-enolase, peptidyl-prolyl cis-trans isomerase (Pin-1), and ATP synthase subunit ? mitochondrial. Several of these proteins have previously been implicated in in vitro and in vivo models and subjects with AD. Additionally, using redox proteomics analyses we identified two oxidatively-modified proteins: phosphatidylethanolamine-binding protein 1 and Pin-1 with decreased levels of protein 3-nitrotyrosine in J20 Tg mice relative to NTg. Western blotting and immunoprecipitation analyses were used to validate proteomics results. Overall, these studies provide information about changes in the brain proteome as a result of A? deposition and clues with which to further direct studies on elucidating AD pathogenesis. PMID:21223993

Robinson, R A S; Lange, M B; Sultana, R; Galvan, V; Fombonne, J; Gorostiza, O; Zhang, J; Warrier, G; Cai, J; Pierce, W M; Bredesen, D E; Butterfield, D A

2011-03-17

271

Amyloid plaques, neurofibrillary tangles and neuronal loss in brains of transgenic mice overexpressing a C-terminal fragment of human amyloid precursor protein.  

Science.gov (United States)

Alzheimer's disease (AD) affects more than 30% of people over 80 years of age. The aetiology and pathogenesis of this progressive dementia is poorly understood, but symptomatic disease is associated histopathologically with amyloid plaques, neurofibrillary tangles and neuronal loss primarily in the temporal lobe and neocortex of the brain. The core of the extracellular plaque is a derivative of the amyloid precursor protein (APP), referred to as beta/A4, and contains the amino-acid residues 29-42 that are normally embedded in the membrane-spanning region of the precursor. The cellular source of APP and the relationship of its deposition to the neuropathology of AD is unknown. To investigate the relationship between APP overexpression and amyloidogenesis, we have developed a vector to drive expression specifically in neurons of a C-terminal fragment of APP that contains the beta/A4 region, and have used a transgenic mouse system to insert and express this construct. We report here that overexpression of this APP transgene in neurons is sufficient to produce extracellular dense-core amyloid plaques, neurofibrillary tangles and neuronal degeneration similar to that in the AD brain. PMID:1793460

Kawabata, S; Higgins, G A; Gordon, J W

1991-12-12

272

Serum Monocyte Chemoattractant Protein-1 in Pancreatic Cancer  

OpenAIRE

Background/Aims. Pancreatic ductal adenocarcinoma (PDA) has etiological association with chronic inflammation. Elevated circulating levels of inflammatory mediators, such as monocyte chemoattractant protein-1 (MCP-1), are found in obese individuals. We hypothesized that serum MCP-1 levels are elevated in obese PDA patients. Methods. ELISA was used to analyze MCP-1 serum levels in PDA (n = 62) and intraductal papillary mucinous neoplasms (IPMN) (n = 27). Recursive partitioning statistical anal...

Yeo, Charles J.; Galina Chipitsyna; Harish Lavu; Jennifer Sullivan; Terry Hyslop; Qiaoke Gong; Arafat, Hwyda A.

2011-01-01

273

Serum Copper and Plasma Protein Status in Normal Pregnancy  

Directory of Open Access Journals (Sweden)

Full Text Available AbstractBackground: Gradual alteration of serum copper and some plasma protein levels may occur with advancement of pregnancy, which is associated with increased maternal and infant morbidity and mortality.Objective: To observe serum copper and plasma protein levels in normal pregnant women of different trimesters in order to find out their nutritional status.Methods: This cross sectional study was carried out in the Department of Physiology, Sir Salimullah Medical College (SSMC, Dhaka, between 1st January 2010 and December 2010. Ninety normal pregnant women of different trimesters with age 20-30 years were included in the study group. They were selected from Out Patient Department of Obstetrics and Gynaecology, SSMC. Age matched 30 non-pregnant women were taken as control. Serum copper level was measured by Spectrophotometric method, serum total protein and albumin levels were estimated by standard method. Statistical analysis was done by one way ANOVA, Bonferroni and Pearson’s correlation coefficient test as applicable.Results: Serum Cu levels were significantly higher in all trimesters of pregnant women compared to control. Again, this value was significantly higher in 3rd trimester than that of in 1st and 2nd trimester and also in 2nd trimester than that of in 1st trimester. In addition, mean serum total protein level was significantly lower in 3rd trimester than control but no statistically significant difference was observed among different trimesters. Again, mean serum albumin level was significantly lower in 2nd and 3rd trimester than 1st trimester and control. In addition, serum Cu concentration showed significant positive correlation with different trimesters of gestation.Conclusion: This study reveals that hypercupremia along with hypoproteinemia occur in pregnant women from 1st to 3rd trimester of gestation. This gradual alteration of micro and macronutrients become more profound with advancement of pregnancy.

Nushrat Noor, Nasim Jahan, Nayma Sultana

2012-12-01

274

Effects of edaravone on amyloid-? precursor protein processing in SY5Y-APP695 cells.  

Science.gov (United States)

Previous reports have revealed that reactive oxygen species (ROS) is involved in the development of Alzheimer's disease (AD), and recent studies indicate that free radical-generating systems can regulate amyloid-? precursor protein (APP) processing. Edaravone is a novel free radical scavenger currently used to reduce cerebral damages after acute cerebral infarction. In the present study, we used SH-SY5Y cells stably transfected with the human "Swedish" APP mutation APP695 (SY5Y-APP695swe) as an in vitro model to investigate the effect of edaravone on APP processing. The result showed that edaravone treatment for 24 h down-regulated ?-amyloid (A?) production in a dose-dependent manner. Moreover, edaravone modulated APP processing by increasing ?-secretase-derived APP fragments and decreasing ?-secretase-derived APP fragments. In addition, the mRNA and protein levels of insulin degrading enzyme (IDE) and neprilysin (NEP), two key A? degrading enzymes, were not changed after edaravone administration. Taken together, our data suggested that edaravone played an important role in regulating A? production by enhancing the non-amyloidogenic pathway and inhibiting the amyloidogenic pathway. Thus, edaravone may be potentially useful for treating Alzheimer's disease (AD). PMID:23325603

Shen, Yue-E; Wang, Yan; Yu, Gui-Chun; Liu, Chao; Zhang, Zhen-Yu; Zhang, Li-Ming

2013-08-01

275

Ketamine reduces amyloid ?-protein degradation by suppressing neprilysin expression in primary cultured astrocytes.  

Science.gov (United States)

Pathological accumulation of cortical amyloid ?-protein (A?) is an early and consistent feature of Alzheimer's disease (AD). A? levels in the brain are determined by production and catabolism. Previous studies have suggested that deficits in the brain expression of neprilysin (NEP) and the insulin-degrading enzyme (IDE), which are both proteases involved in amyloid degradation, may promote A? deposition in patients with sporadic late-onset AD. Because the incidence of AD increases after surgical intervention, we examined whether ketamine, which is a general anaesthetic with neuroprotective properties for excitotoxic ischaemic damage, is associated with A? degradation by inducing NEP and IDE expression. The non-competitive N-methyl-d-aspartate receptor antagonist ketamine and MK801 significantly decreased the expression of NEP, but not IDE, in a concentration- and time-dependent manner through the dephosphorylation of p38 mitogen-activated protein kinase (MAPK) in cultured rat astrocytes. Furthermore, NEP-reduced reagents significantly suppressed the degradation of exogenous A? in cultured astrocytes. These results suggested that ketamine suppresses the A? degradation of NEP by reducing p38 MAPK-mediated pathway activity. PMID:23624023

Yamamoto, Naoki; Arima, Hajime; Naruse, Kaori; Kasahara, Rika; Taniura, Hideo; Hirate, Hiroyuki; Sugiura, Takeshi; Suzuki, Kenji; Sobue, Kazuya

2013-06-17

276

Beta-secretase cleavage of Alzheimer's amyloid precursor protein by the transmembrane aspartic protease BACE.  

Science.gov (United States)

Cerebral deposition of amyloid beta peptide (Abeta) is an early and critical feature of Alzheimer's disease. Abeta generation depends on proteolytic cleavage of the amyloid precursor protein (APP) by two unknown proteases: beta-secretase and gamma-secretase. These proteases are prime therapeutic targets. A transmembrane aspartic protease with all the known characteristics of beta-secretase was cloned and characterized. Overexpression of this protease, termed BACE (for beta-site APP-cleaving enzyme) increased the amount of beta-secretase cleavage products, and these were cleaved exactly and only at known beta-secretase positions. Antisense inhibition of endogenous BACE messenger RNA decreased the amount of beta-secretase cleavage products, and purified BACE protein cleaved APP-derived substrates with the same sequence specificity as beta-secretase. Finally, the expression pattern and subcellular localization of BACE were consistent with that expected for beta-secretase. Future development of BACE inhibitors may prove beneficial for the treatment of Alzheimer's disease. PMID:10531052

Vassar, R; Bennett, B D; Babu-Khan, S; Kahn, S; Mendiaz, E A; Denis, P; Teplow, D B; Ross, S; Amarante, P; Loeloff, R; Luo, Y; Fisher, S; Fuller, J; Edenson, S; Lile, J; Jarosinski, M A; Biere, A L; Curran, E; Burgess, T; Louis, J C; Collins, F; Treanor, J; Rogers, G; Citron, M

1999-10-22

277

Mechanism of amyloid ?-protein dimerization determined using single-molecule AFM force spectroscopy  

Science.gov (United States)

A?42 and A?40 are the two primary alloforms of human amyloid ?-protein (A?). The two additional C-terminal residues of A?42 result in elevated neurotoxicity compared with A?40, but the molecular mechanism underlying this effect remains unclear. Here, we used single-molecule force microscopy to characterize interpeptide interactions for A?42 and A?40 and corresponding mutants. We discovered a dramatic difference in the interaction patterns of A?42 and A?40 monomers within dimers. Although the sequence difference between the two peptides is at the C-termini, the N-terminal segment plays a key role in the peptide interaction in the dimers. This is an unexpected finding as N-terminal was considered as disordered segment with no effect on the A? peptide aggregation. These novel properties of A? proteins suggests that the stabilization of N-terminal interactions is a switch in redirecting of amyloids form the neurotoxic aggregation pathway, opening a novel avenue for the disease preventions and treatments.

Lv, Zhengjian; Roychaudhuri, Robin; Condron, Margaret M.; Teplow, David B.; Lyubchenko, Yuri L.

2013-10-01

278

Screening serum hepatocellular carcinoma-associated proteins by SELDI-based protein spectrum analysis  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To find out potential serum hepatocellular carcinoma (HCC-associated proteins with low molecular weight and low abundance by SELDI-based serum protein spectra analysis, that will have much application in the diagnosis or differentiated diagnosis of HCC, as well as giving a better understanding of the mechanism of hepato-carcinogenesis.METHODS: Total serum samples were collected with informed consent from 81 HCC patients with HBV(+/cirrhosis(+, 36 cirrhosis patients and 43 chronic hepatitis B patients. Serum protein fingerprint profiles were first generated by selected WCX2 protein chip capture integrating with SELDI-TOF-MS, then normalized and aligned by Ciphergen SELDI Software 3.1.1 with Biomarker Wizard. Comparative analysis of the intensity of corresponding protein fingerprint peaks in normalized protein spectra, some protein peaks with significant difference between HCC and cirrhosis or chronic hepatitis B were found.RESULTS: One hundred and twenty-eight serum protein peaks between 2000 and 30 000Da were identified under the condition of signal-to-noise > 5 and minimum threshold for cluster > 20%. Eighty-seven of these proteins were showed significant differences in intensity between HCC and cirrhosis (P < 0.05. Of the above differential proteins, 45 proteins had changes greater than two-fold, including 15 upregulated proteins and 30 downregulated proteins in HCC serum. Between HCC and chronic hepatitis B, 9 of 52 differential proteins (P < 0.05 had intensities of more than two-fold, including 2 upregulated proteins and 7 downregulated proteins in HCC serum. Between cirrhosis and chronic hepatitis B, 28 of 79 significant differential proteins (P < 0.05 changes greater than two-fold in intensity, including 17 upregulated proteins and 11 downregulated proteins in cirrhosis serum. For the analysis of these leading differential proteins in subtraction difference mode among three diseases, the five common downregulated proteins in HCC serum (M/Z 2870, 3941, 2688, 3165, 5483 and two common upregulated proteins (M/Z 3588, 2017 in HCC and cirrhosis serum were screened.CONCLUSION: Because the interference of unspecific secreted proteins from hepatitis B and cirrhosis could be eliminated partly in HCC serum under subtraction difference analysis, these seven common differential proteins have the obvious advantage of specificity for evaluating the pathological state of HCC and might become novel candidate biomarkers in the diagnosis of HCC.

Jie-Feng Cui, Yin-Kun Liu, Hai-Jun Zhou, Xiao-Nan Kang, Cheng Huang, Yi-Feng He, Zhao-You Tang, Toshimasa Uemura

2008-02-01

279

Molecular cloning and nucleotide sequence of cDNA for murine senile amyloid protein: nucleotide substitutions found in apolipoprotein A-II cDNA of senescence accelerated mouse (SAM).  

OpenAIRE

cDNA clones encoding the murine senile amyloid protein (ASSAM) have been isolated from animal models of accelerated senescence (SAM-P/1) and from normal aging (SAM-R/1). Immunochemical and protein sequence studies revealed that apolipoprotein (apo) A-II is a serum precursor of ASSAM. A 17-base synthetic oligonucleotide based on residues 39-44 of ASSAM was used as a hybridization probe for screening newly constructed SAM-P/1 and SAM-R/1 liver cDNA libraries. The structure of murine apo A-II cD...

Kunisada, T.; Higuchi, K.; Aota, S.; Takeda, T.; Yamagishi, H.

1986-01-01

280

Intracerebroventricular injection of anti-Fas activates the hypothalamus-pituitary-adrenal axis and induces peripheral interleukin-6 and serum amyloid A in mice: comparison with other ligands of the tumor necrosis factor/nerve growth factor receptor superfamily.  

Science.gov (United States)

Fas is a receptor of the tumor necrosis factor (TNF)/ nerve growth factor (NGF) receptor superfamily that mediates apoptosis and some inflammatory changes. As the central administration of TNF is known to activate the hypothalamus-pituitary-adrenal axis (HPAA) and to induce peripheral responses including induction of serum interleukin (IL)-6 and serum amyloid A (SAA), we investigated the effects of intracerebroventricular (i.c.v.) administration of agonist anti-Fas monoclonal antibody Jo2. Centrally administered anti-Fas (1 microg/mouse, i.c.v.) induced elevated levels of corticosterone, IL-6, and SAA comparable to those observed after i.c.v. administration of recombinant murine TNF. On the other hand, administration of murine NGF did not elevate serum corticosterone or IL-6, but induced SAA. Thus, Fas can trigger a centrally mediated anti-inflammatory response (HPAA activation) and induce a peripheral acute-phase response comparable to that induced with TNF, whereas NGF induces only acute-phase proteins. PMID:9811328

Benigni, F; Sacco, S; Aloe, L; Ghezzi, P

1998-11-01

281

Smoking and serum proteins in atomic bomb survivors in Hiroshima  

International Nuclear Information System (INIS)

Associations of smoking habit with serum levels of total protein as well as protein fractions were studied in a population consisting of 4,739 atomic bomb survivors and unexposed control subjects in Hiroshima who participated in the 1979-81 period of the Adult Health Study, an on-going health follow-up program of the RERF. Smoking was strongly related to serum protein concentration after correction for age, sex, and body mass index. Among current smokers as compared to nonsmokers, levels of total protein, ? globulin, and ? globulin were significantly lower (p1 and ?2 globulin were significantly higher (p1 globulin. Duration of smoking (years) was related to increased ?1 and ?2 globulin. Smoking duration was also associated with albumin level but the trend was not monotonic. The radiation exposure effect on serum protein level was significant in several instances but was in general much smaller than the smoking effect. Its inclusion in the regression models did not noticeably affect the association between smoking and serum proteins. (author)

282

AMYLOID-? PEPTIDE BINDS TO MICROTUBULE-ASSOCIATED PROTEIN 1B (MAP1B)  

OpenAIRE

Extracellular and intraneuronal formation of amyloid-beta aggregates have been demonstrated to be involved in the pathogenesis of Alzheimer’s disease. However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of targets have deleterious effects on cellular functions. In the present study we have shown for the first time that amyloid-beta 1-42 bound to a peptide comprising the microtubule bindi...

Gevorkian, Goar; Gonzalez-noriega, Alfonso; Acero, Gonzalo; Ordon?ez, Jorge; Michalak, Colette; Munguia, Maria Elena; Govezensky, Tzipe; Cribbs, David H.; Manoutcharian, Karen

2008-01-01

283

Mitosis-specific phosphorylation of amyloid precursor protein at Threonine 668 leads to its altered processing and association with centrosomes  

OpenAIRE

Abstract Background Atypical expression of cell cycle regulatory proteins has been implicated in Alzheimer's disease (AD), but the molecular mechanisms by which they induce neurodegeneration are not well understood. We examined transgenic mice expressing human amyloid precursor protein (APP) and presenilin 1 (PS1) for changes in cell cycle regulatory proteins to determine whether there is a correlation between cell cycle activation and pathology development in AD. Resu...

Judge Monique; Hornbeck Lisa; Potter Huntington; Padmanabhan Jaya

2011-01-01

284

Racemization of Asp23 residue affects the aggregation properties of Alzheimer amyloid beta protein analogues.  

Science.gov (United States)

The beta proteins in amyloid deposits of Alzheimer's disease have been found to be racemized and/or isomerized at their Asp residues (Roher, A. E., Lowenson, J. D., Clarke, S., Wolkow, C., Wang, R., Cotter, R. J., Reardon, I. M., Zurcher-Neely, H. A., Heinrikson, R. L., Ball, M. J., and Greenberg, B. D. (1993) J. Biol. Chem. 268, 3072-3083). To elucidate the effect of racemization on the aggregation properties of beta proteins, we synthesized four beta protein analogues in which D-Asp was substituted for L-Asp residues, i.e. normal beta 1-35, [D-Asp7]beta 1-35, [D-Asp23]beta 1-35, and [D-Asp7,D-Asp23]beta 1-35. The aggregation and fibril formation of the peptides were examined by means of spectrophotometry, sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE), and electron microscopy. Of the four peptides, [D-Asp23]beta 1-35 showed the earliest increase in turbidity and appearance of a smear in SDS-PAGE. This was followed by [D-Asp7,D-Asp23]beta 1-35 and normal beta 1-35. [D-Asp7]beta 1-35 was considerably delayed in showing these signs of aggregation. Corresponding with the increase in turbidity and the appearance of a smear in SDS-PAGE, fibril formation was observed in electron microscopy. These results reveal that the aggregation properties of beta 1-35 peptides are affected by racemization of their Asp residues depending on their position. Racemization at amino acid position 23 accelerated the peptide aggregation and fibril formation, while that at position 7 slowed down this reaction. This suggests that the site-specific racemization of beta protein may be involved in the amyloid fibril formation in Alzheimer's disease. PMID:8144598

Tomiyama, T; Asano, S; Furiya, Y; Shirasawa, T; Endo, N; Mori, H

1994-04-01

285

Protein binding and serum bactericidal activities of vancomycin and teicoplanin.  

OpenAIRE

In a randomized crossover study, the protein binding and serum bactericidal activities (SBAs) of vancomycin and teicoplanin against Staphylococcus aureus and Streptococcus pyogenes were investigated in six healthy volunteers. Total concentrations in serum 1 h postadministration of vancomycin and teicoplanin were 25.5 +/- 2.7 and 10.8 +/- 8.9 mg/liter, respectively; mean free concentrations were 14.6 +/- 2.0 and 0.6 +/- 0.9 mg/liter, respectively. Protein binding for vancomycin was 36.9% +/- 2...

Dykhuizen, R. S.; Harvey, G.; Stephenson, N.; Nathwani, D.; Gould, I. M.

1995-01-01

286

Innate immunity from serum protein derivatives  

OpenAIRE

E??? noto che esiste un ampio gruppo di proteine, incluse proteine della segnalazione endocrina, della matrice extracellulare, della cascata del complemento e del latte, contenenti al loro interno altre unit?? funzionali, che potrebbero essere rilasciate in vivo in seguito a tagli proteolitici, dotate di attivit?? biologiche non prevedibili a partire dalla sequenza o dall???attivit?? della proteina precursore. L???esistenza di questi frammenti peptidici, denomina...

Zanello, Pier Paolo

2014-01-01

287

Serum protein inhibition of thyrotropin binding to human thyroid tissue  

International Nuclear Information System (INIS)

We used a modificaton of the TSH radioreceptor assay to detect TSH-binding inhibition (TBI) activity in serum and serum fractions from normal subjects and patients with Graves' disease. TBI activity is present in normal IgG prepared by DEAE-Sephadex chromatography and in normal globulins prepared by precipitation at 1.6 M ammonium sulfate. Other normal serum proteins also had TBI activity when large concentrations were tested. Gel filtration chromatography and powder block electrophoresis were used to prepare fractions of normal and Graves' disease sera. In these fractions from normal serum, TBI activity was found in both ?-globulin and ?-globulin-albumin fractions electrophoretically and in both 7S and 4S peaks from gel filtration. TBI activity from Graves' disease patients' sera was similarly distributed, but relatively more TBI accompanied the electrophoretic ?-globulins. Sepharose Protein-A and anti-IgG were used as immunoabsorbents to isolate and purify IgG from normal and Graves' disease sera. TBI activity in IgG was proportional to the IgG concentration, indicating that the TBI which migrates as a ?-globulin electrophoretically is an IgG and thus may possibly be an antibody. Inhibitory activity found in normal serum globulins and in the non-IgG fractions of both normal and abnormal sera seriously interferes with attempts to use the TSH radioreceptor assay to study the hypothesized anti-TSH receptor antibody in the serum of patients with Graves' disease of patients with Graves' disease

288

Doped diamond-like carbon coatings for surgical instruments reduce protein and prion-amyloid biofouling and improve subsequent cleaning.  

Science.gov (United States)

Doped diamond-like carbon (DLC) coatings offer potential antifouling surfaces against microbial and protein attachment. In particular, stainless steel surgical instruments are subject to tissue protein and resilient prion protein attachment, making decontamination methods used in sterile service departments ineffective, potentially increasing the risk of iatrogenic Creutzfeldt-Jakob disease during surgical procedures. This study examined the adsorption of proteins and prion-associated amyloid to doped DLC surfaces and the efficacy of commercial cleaning chemistries applied to these spiked surfaces, compared to titanium nitride coating and stainless steel. Surfaces inoculated with ME7-infected brain homogenate were visualised using SYPRO Ruby/Thioflavin T staining and modified epi-fluorescence microscopy before and after cleaning. Reduced protein and prion amyloid contamination was observed on the modified surfaces and subsequent decontamination efficacy improved. This highlights the potential for a new generation of coatings for surgical instruments to reduce the risk of iatrogenic CJD infection. PMID:22694725

Secker, T J; Hervé, R; Zhao, Q; Borisenko, K B; Abel, E W; Keevil, C W

2012-01-01

289

Relationship Between Duration, Protein Loss Through Scaling And Serum Protein Levels In Exfoliative Dermatitis  

Directory of Open Access Journals (Sweden)

Full Text Available Forty patients of exfoiliative dermatitis (ED, 35 of which were male and 5 female, constituted the study sample. The mean duration of ED were 10, 15 and 5 days for ED secondary to psoriasis, exzema and others, and drug reactions respectively. Fourteen (35% patients had reduced serum protein levels of which 12 (30% had reversal of albumin to globulin ratio. Normal serum protein levels were maintained up to 12.8 g of daily protein loss through scaling. In ED secondary to psoriasis, a mean duration of 15 days and protein loss of the 16 g per day through scaling were found to have significant (p<0.01 lowering of serum protein levels. In ED due to eczema and drug reactions, it was not significant. Total serum protein level was inversely proportional to the amount of protein loss through scaling and duration of the disease.

Kantharaj Garehatty R

2002-01-01

290

Lead exposure in pheochromocytoma cells induces persistent changes in amyloid precursor protein gene methylation patterns.  

Science.gov (United States)

It has been suggested that lead (Pb) exposure in early life may increase amyloid precursor protein (APP) expression and promote the pathogenesis of Alzheimer's disease in old age. The current study examined whether the DNA methylation patterns of APP gene in rat pheochromocytoma (PC12) cells changed after Pb acetate exposure. Undifferentiated PC12 cells were exposed to three doses of Pb acetate (50, 250, and 500 nM) and one control for 2 days or 1 week. The methylation patterns of APP promoter and global DNA methylation were analyzed. The DNA methyltransferase 1 (DNMT1) expression and the level of amyloid ? peptide (A?) were also investigated. The results showed that the exposure of the three concentrations of Pb acetate could make the APP promoter hypomethylated. The global DNA methylation level and the expression of DNMT1 were changed in the 500 nM group after 2 days exposure and in the 250 and 500 nM group after 7 days exposure. Thus, Pb may exert neurotoxic effects through mechanisms that alter the global and promoter methylation patterns of APP gene. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012. PMID:22764079

Li, Yuan-Yuan; Chen, Tian; Wan, Yanjian; Xu, Shun-qing

2012-08-01

291

Glycogen synthase kinase 3 inhibition promotes lysosomal biogenesis and autophagic degradation of the amyloid-? precursor protein.  

Science.gov (United States)

Alzheimer's disease (AD) has been associated with altered activity of glycogen synthase kinase 3 (GSK3) isozymes, which are proposed to contribute to both neurofibrillary tangles and amyloid plaque formation. However, the molecular basis by which GSK3 affects the formation of A? remains unknown. Our aim was to identify the underlying mechanisms of GSK3-dependent effects on the processing of amyloid precursor protein (APP). For this purpose, N2a cells stably expressing APP carrying the Swedish mutation were treated with specific GSK3 inhibitors or transfected with GSK3?/? short interfering RNA. We show that inhibition of GSK3 leads to decreased expression of APP by enhancing its degradation via an increase in the number of lysosomes. This induction of the lysosomal/autophagy pathway was associated with nuclear translocation of transcription factor EB (TFEB), a master regulator of lysosomal biogenesis. Our data indicate that GSK3 inhibition reduces A? through an increase of the degradation of APP and its carboxy-terminal fragment (CTF) by activation of the lysosomal/autophagy pathway. These results suggest that an increased propensity toward autophagic/lysosomal alterations in AD patients could have consequences for neuronal function. PMID:22927642

Parr, Callum; Carzaniga, Raffaela; Gentleman, Steve M; Van Leuven, Fred; Walter, Jochen; Sastre, Magdalena

2012-11-01

292

ATP-binding cassette transporter A7 regulates processing of amyloid precursor protein in vitro.  

Science.gov (United States)

ATP-binding cassette transporter A7 (ABCA7) is expressed in the brain and, like its closest homolog ABCA1, belongs to the ABCA subfamily of full-length ABC transporters. ABCA1 promotes cellular cholesterol efflux to lipid-free apolipoprotein acceptors and also inhibits the production of neurotoxic beta-amyloid (Abeta) peptides in vitro. The potential functions of ABCA7 in the brain are unknown. This study investigated the ability of ABCA7 to regulate cholesterol efflux to extracellular apolipoprotein acceptors and to modulate Abeta production. The transient expression of ABCA7 in human embryonic kidney cells significantly stimulated cholesterol efflux (fourfold) to apolipoprotein E (apoE) discoidal lipid complexes but not to lipid-free apoE or apoA-I. ABCA7 also significantly inhibited Abeta secretion from Chinese hamster ovary cells stably expressing human amyloid precursor protein (APP) or APP containing the Swedish K670M671-->N670L671 mutations when compared with mock-transfected cells. Studies with fluorogenic substrates indicated that ABCA7 had no impact on alpha-, beta-, or gamma-secretase activities. Live cell imaging of Chinese hamster ovary cells expressing APP-GFP indicated an apparent retention of APP in a perinuclear location in ABCA7 co-transfected cells. These studies indicate that ABCA7 has the capacity to stimulate cellular cholesterol efflux to apoE discs and regulate APP processing resulting in an inhibition of Abeta production. PMID:18429932

Chan, Sharon L; Kim, Woojin Scott; Kwok, John B; Hill, Andrew F; Cappai, Roberto; Rye, Kerry-Anne; Garner, Brett

2008-07-01

293

Genetic association to the amyloid plaque associated protein gene COL25A1 in Alzheimer's disease.  

Science.gov (United States)

The COL25A1 gene, located in 4q25, encodes the CLAC protein, which has been implicated in Alzheimer's disease (AD) pathogenesis. CLAC was originally identified in amyloid preparations from AD brain and has been shown to be associated with amyloid plaques, inhibition of Abeta-fibril elongation and increased protease resistance of Abeta-fibrils through direct binding to Abeta. These biochemical data as well as the genomic location of the COL25A1 gene in chromosome 4q25 where we previously have reported a weak linkage-signal in Swedish AD families encouraged us to perform a case-control association study of two LD blocks in COL25A1 using 817 AD cases and 364 controls. The LD blocks cover a putative Abeta-binding motif and the variable 3' end of the gene. The analyses indicated association to three of eight analysed SNPs. We found further support for the association by replication in a Swedish population-based longitudinal sample set (n=926). Thus, in addition to the biochemical data, there is now genetic evidence of association between COL25A1 and risk for Alzheimer's disease. PMID:18501477

Forsell, Charlotte; Björk, Behnosh Fakhri; Lilius, Lena; Axelman, Karin; Fabre, Susanne Froelich; Fratiglioni, Laura; Winblad, Bengt; Graff, Caroline

2010-03-01

294

Dual roles of the transmembrane protein p23/TMP21 in the modulation of amyloid precursor protein metabolism  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Alzheimer's disease (AD is characterized by cerebral deposition of ?-amyloid (A? peptides. A? is released from ectodomain cleaved amyloid precursor protein (APP via intramembranous proteolysis by ?-secretase, a complex consisting of presenilin and a few other proteins. p23/TMP21, a member of the p24 family type I transmembrane proteins, was recently identified as a presenilin complex component capable of modulating ?-secretase cleavage. The p24 family proteins form oligomeric complexes and regulate vesicular trafficking in the early secretory pathway, but their role in APP trafficking has not been investigated. Results Here, we report that siRNA-mediated depletion of p23 in N2a neuroblastoma and HeLa cells produces concomitant knockdown of additional p24 family proteins and increases secretion of sAPP. Furthermore, intact cell and cell-free A? production increases following p23 knockdown, similar to data reported earlier using HEK293 cells. However, we find that p23 is not present in mature ?-secretase complexes isolated using an active-site ?-secretase inhibitor. Depletion of p23 and expression of a familial AD-linked PS1 mutant have additive effects on A?42 production. Knockdown of p23 expression confers biosynthetic stability to nascent APP, allowing its efficient maturation and surface accumulation. Moreover, immunoisolation analyses show decrease in co-residence of APP and the APP adaptor Mint3. Thus, multiple lines of evidence indicate that p23 function influences APP trafficking and sAPP release independent of its reported role in ?-secretase modulation. Conclusion These data assign significance to p24 family proteins in regulating APP trafficking in the continuum of bidirectional transport between the ER and Golgi, and ascribe new relevance to the regulation of early trafficking in AD pathogenesis.

Wieland Felix T

2007-02-01

295

Genome-wide association study identifies two novel regions at 11p15.5-p13 and 1p31 with major impact on acute-phase serum amyloid A.  

Science.gov (United States)

Elevated levels of acute-phase serum amyloid A (A-SAA) cause amyloidosis and are a risk factor for atherosclerosis and its clinical complications, type 2 diabetes, as well as various malignancies. To investigate the genetic basis of A-SAA levels, we conducted the first genome-wide association study on baseline A-SAA concentrations in three population-based studies (KORA, TwinsUK, Sorbs) and one prospective case cohort study (LURIC), including a total of 4,212 participants of European descent, and identified two novel genetic susceptibility regions at 11p15.5-p13 and 1p31. The region at 11p15.5-p13 (rs4150642; p?=?3.20×10(-111)) contains serum amyloid A1 (SAA1) and the adjacent general transcription factor 2 H1 (GTF2H1), Hermansky-Pudlak Syndrome 5 (HPS5), lactate dehydrogenase A (LDHA), and lactate dehydrogenase C (LDHC). This region explains 10.84% of the total variation of A-SAA levels in our data, which makes up 18.37% of the total estimated heritability. The second region encloses the leptin receptor (LEPR) gene at 1p31 (rs12753193; p?=?1.22×10(-11)) and has been found to be associated with CRP and fibrinogen in previous studies. Our findings demonstrate a key role of the 11p15.5-p13 region in the regulation of baseline A-SAA levels and provide confirmative evidence of the importance of the 1p31 region for inflammatory processes and the close interplay between A-SAA, leptin, and other acute-phase proteins. PMID:21124955

Marzi, Carola; Albrecht, Eva; Hysi, Pirro G; Lagou, Vasiliki; Waldenberger, Melanie; Tönjes, Anke; Prokopenko, Inga; Heim, Katharina; Blackburn, Hannah; Ried, Janina S; Kleber, Marcus E; Mangino, Massimo; Thorand, Barbara; Peters, Annette; Hammond, Christopher J; Grallert, Harald; Boehm, Bernhard O; Kovacs, Peter; Geistlinger, Ludwig; Prokisch, Holger; Winkelmann, Bernhard R; Spector, Tim D; Wichmann, H-Erich; Stumvoll, Michael; Soranzo, Nicole; März, Winfried; Koenig, Wolfgang; Illig, Thomas; Gieger, Christian

2010-11-01

296

Amyloid-Beta Protein Clearance and Degradation (ABCD) Pathways and their Role in Alzheimer's Disease.  

Science.gov (United States)

Amyloid-? proteins (A?) of 42 (A?42) and 40 aa (A?40) accumulate as senile plaques (SP) and cerebrovascular amyloid protein deposits that are defining diagnostic features of Alzheimer's disease (AD). A number of rare mutations linked to familial AD (FAD) on the A? precursor protein (APP), Presenilin-1 (PS1), Presenilin- 2 (PS2), Adamalysin10, and other genetic risk factors for sporadic AD such as the ?4 allele of Apolipoprotein E (ApoE-?4) foster the accumulation of A? and also induce the entire spectrum of pathology associated with the disease. A? accumulation is therefore a key pathological event and a prime target for the prevention and treatment of AD. APP is sequentially processed by ?-site APP cleaving enzyme (BACE1) and ?-secretase, a multisubunit PS1/PS2-containing integral membrane protease, to generate A?. Although A? accumulates in all forms of AD, the only pathways known to be affected in FAD increase A? production by APP gene duplication or via base substitutions on APP and ?-secretase subunits PS1 and PS2 that either specifically increase the yield of the longer A?42 or both A?40 and A?42. However, the vast majority of AD patients accumulate A? without these known mutations. This led to proposals that impairment of A? degradation or clearance may play a key role in AD pathogenesis. Several candidate enzymes, including Insulin-degrading enzyme (IDE), Neprilysin (NEP), Endothelin-converting enzyme (ECE), Angiotensin converting enzyme (ACE), Plasmin, and Matrix metalloproteinases (MMPs) have been identified and some have even been successfully evaluated in animal models. Several studies also have demonstrated the capacity of ?-secretase inhibitors to paradoxically increase the yield of A? and we have recently established that the mechanism is by skirting A? degradation. This review outlines major cellular pathways of A? degradation to provide a basis for future efforts to fully characterize the panel of pathways responsible for A? turnover. PMID:25523424

Baranello, Robert J; Bharani, Krishna L; Padmaraju, Vasudevaraju; Chopra, Nipun; Lahiri, Debomoy K; Greig, Nigel H; Pappolla, Miguel A; Sambamurti, Kumar

2015-01-01

297

The A?-clearance protein transthyretin, like neprilysin, is epigenetically regulated by the amyloid precursor protein intracellular domain.  

Science.gov (United States)

Proteolytic cleavage of the amyloid precursor protein (APP) by the successive actions of ?- and ?-secretases generates several biologically active metabolites including the amyloid ?-peptide (A?) and the APP intracellular domain (AICD). By analogy with the Notch signalling pathway, AICD has been proposed to play a role in transcriptional regulation. Among the cohort of genes regulated by AICD is the A?-degrading enzyme neprilysin (NEP). AICD binds to the NEP promoter causing transcriptional activation by competitive replacement with histone deacetylases (HDACs) leading to increased levels of NEP activity and hence increased A? clearance. We now show that the A?-clearance protein transthyretin (TTR) is also epigenetically up-regulated by AICD. Like NEP regulation, AICD derived specifically from the neuronal APP isoform, APP695 , binds directly to the TTR promoter displacing HDAC1 and HDAC3. Cell treatment with the tyrosine kinase inhibitor Gleevec (imatinib) or with the alkalizing agent NH4 Cl causes an accumulation of 'functional' AICD capable of up-regulating both TTR and NEP, leading to a reduction in total cellular A? levels. Pharmacological regulation of both NEP and TTR might represent a viable therapeutic target in Alzheimer's disease. PMID:24528201

Kerridge, Caroline; Belyaev, Nikolai D; Nalivaeva, Natalia N; Turner, Anthony J

2014-08-01

298

Blood serum components and serum protein test of Hybro-PG broilers of different ages  

Directory of Open Access Journals (Sweden)

Full Text Available Blood serum samples of HYBRO PG broilers were analyzed, with 30 samples collected from 21-day-old broilers (G1, 30 from 35-day-old birds (G2, and 30 from 42-day-old birds (G3, with the aim of establishing normal values of some blood serum parameters. The activities of the enzymes gamma-glutamyl-transferase (GGT, aspartate aminotransferase (AST, creatine kinase (CK, alkaline phosphatase (ALP, and lactate dehydrogenase (LDH, serum levels of total calcium, calcium ion, phosphorus, sodium, potassium, magnesium, chlorides, creatinine, uric acid, triglycerides, cholesterol, total protein, albumin, total and indirect and direct bilirubin, and electrophoretic profile of serum proteins in acrylamide (SDS-PAGE and agarose gel were determined. There was no influence of age on total bilirubin and albumin levels. All the other evaluated parameters presented differences in at least one age group. Protein electrophoretic profile also changed as a function of age. The obtained results can be considered as normal for the studied ages, and therefore be used as references for the interpretation of laboratory exams of broilers of this genetic line in the evaluated ages.

PRL Silva

2007-12-01

299

EFFECTS OF THYROIDECTOMY ON THE SERUM PROTEIN FRACTIONS IN DOG  

Directory of Open Access Journals (Sweden)

Full Text Available The study on the serum protein electrophoresis following thyroidectomy in A puppies showed a significant decrease in the albumin and -a-ratio associated with a relative increase in gamma and total globulin, but alterations of alpha I and beta globulin were not statistically charcteristic in our thyroidectomized dogs.

N. Guiti

1969-01-01

300

AP-2? regulates amyloid beta-protein stimulation of apolipoprotein E transcription in astrocytes.  

Science.gov (United States)

Two key players involved in Alzheimer's disease (AD) are amyloid beta protein (A?) and apolipoprotein E (apoE). A? increases apoE protein levels in astrocytes which is associated with cholesterol trafficking, neuroinflammatory responses and A? clearance. The mechanism for the increase in apoE protein abundance is not understood. Based on different lines of evidence, we propose that the beta-adrenergic receptor (?AR), cAMP and the transcription factor activator protein-2 (AP-2) are contributors to the A?-induced increase in apoE abundance. This hypothesis was tested in mouse primary astrocytes and in cells transfected with an apoE promoter fragment with binding sites for AP-2. A?(42) induced a time-dependent increase in apoE mRNA and protein levels which were significantly inhibited by ?AR antagonists. A novel finding was that A? incubation significantly reduced AP-2? levels and significantly increased AP-2? levels in the nuclear fraction. The impact of A?-induced translocation of AP-2 into the nucleus was demonstrated in cells expressing AP-2 and incubated with A?(42). AP-2 expressing cells had enhanced activation of the apoE promoter region containing AP-2 binding sites in contrast to AP-2 deficient cells. The transcriptional upregulation of apoE expression by A?(42) may be a neuroprotective response to A?-induced cytotoxicity, consistent with apoE's role in cytoprotection. PMID:22325097

Rossello, Ximena S; Igbavboa, Urule; Weisman, Gary A; Sun, Grace Y; Wood, W Gibson

2012-03-20

301

Distinctive serum protein profiles involving abundant proteins in lung cancer patients based upon antibody microarray analysis  

OpenAIRE

Abstract Background Cancer serum protein profiling by mass spectrometry has uncovered mass profiles that are potentially diagnostic for several common types of cancer. However, direct mass spectrometric profiling has a limited dynamic range and difficulties in providing the identification of the distinctive proteins. We hypothesized that distinctive profiles may result from the differential expression of relatively abundant serum proteins associated with the host response.

Rom William N; Greenberg Alissa K; Qiu Ji; Misek David E; Orchekowski Randal P; Kuick Rork; Gao Wei-Min; Brenner Dean E; Omenn Gilbert S; Haab Brian B; Hanash Samir M

2005-01-01

302

Oxidative stress induces macroautophagy of amyloid beta-protein and ensuing apoptosis  

DEFF Research Database (Denmark)

There is increasing evidence for the toxicity of intracellular amyloid beta-protein (Abeta) to neurons and the involvement of lysosomes in this process in Alzheimer disease (AD). We have recently shown that oxidative stress, a recognized determinant of AD, enhances macroautophagy and leads to intralysosomal accumulation of Abeta in cultured neuroblastoma cells. We hypothesized that oxidative stress promotes AD by stimulating macroautophagy of Abeta that further may induce cell death by destabilizing lysosomal membranes. To investigate such possibility, we compared the effects of hyperoxia (40% ambient oxygen) in cultured HEK293 cells that were transfected with an empty vector (Vector), wild-type APP (APPwt), or Swedish mutant APP (APPswe). Exposure to hyperoxia for 5 days increased the number of cells with Abeta-containing lysosomes, as well as the number of apoptotic cells, compared to normoxic conditions. The rate of apoptosis in all three cell lines demonstrated dependence on intralysosomal Abeta content (Vector

Zheng, Lin; Kågedal, Katarina

2009-01-01

303

Substitution of membrane cholesterol with ?-sitosterol promotes nonamyloidogenic cleavage of endogenous amyloid precursor protein.  

Science.gov (United States)

Increasing evidence has linked membrane cholesterol to amyloid precursor protein (APP) processing. ?-Sitosterol (BS) is one of the most common forms of plant sterols, with the structure very similar to that of cholesterol. Using HT22 mouse hippocampal cells, this study investigated whether the substitution of membrane cholesterol with BS influences APP metabolism. It was found that cholesterol/BS substitution promoted nonamyloidogenic processing of APP without affecting membrane fluidity. Additional experiments suggest that the effect of membrane BS on APP metabolism is associated with the migration of APP from lipid rafts toward non-raft regions. Given that dietary BS can enter the brain and accumulates in the plasma membrane of brain cells, these results suggest a potential use of BS in the prevention of Alzheimer's disease. PMID:23707801

Wang, Jisheng; Wu, Fengming; Shi, Chun

2013-09-01

304

Assessment of the Nature Interactions of ?-Amyloid Protein by a Nanoprobe Method.  

Science.gov (United States)

We present a method based on atomic force microscopy (AFM) to assess the work of adhesion between the interfaces of gold AFM tips functionalized with three peptides derived from ?-sheet breaker LPFFD [CLPFFD-NH2 (i0) and their isomers CDLPFF-NH2 (i1) and CLPDFF-NH2 (i2)], and the beta-amyloid protein (A?1-42). ?-Amyloid protein was deposited onto a highly oriented graphite (HOPG) surface as protofibrils and fibrils. The presence of the residues Leu (L), Phe (F), and Phe (F), which are also present in the native sequence, confirm that the peptides are able to bind to the aggregates of A?1-42 fibrils and protofibrils. Force of adhesion data were directly obtained from the maximum force on retraction, and the work of adhesion was calculated from the Jhonson-Kendall-Roberts model (JKR-Model). Both the polar and dispersive contributions to the surface energy of the peptides i0, i1, and i2, as well as A?1-42 fibrils and protofibrils, were determined by means of measuring the contact angle and using the two-fluid method. The macroscopic energies of the functionalized gold surfaces do not differ significantly between isomers, which confirms the similar nature of the peptides i0, i1, and i2 but suggests that the macroscopic measurements are not able to distinguish specific sequences. The nanoprobe reveals a typical adhesion work value associated with the interaction of protofibrils with i0 and i2; this value is three times higher than that of i1. The difference is attributed to the hydrophobic nature of protofibrils, the predominant exposition of hydrophobic residues of the peptides i0 and i2, with respect to i1, and the degree of functionalization. i0 and i2 presented a slight adhesion with A? fibrils, which is associated with the exposed hydrophilic groups of these fibrils (onto HOPG) compared to the protofibrils. However, i1 showed interaction with both A? fibrils and protofibrils. For this, we propose an explanation based on the fact that the peptide i1 locates itself adjacent to the gold surface of the probe, concealing their hydrophobic groups and therefore decreasing the probability of interaction with A? fibrils and protofibrils. The peptide-gold nano probe represents a useful tool to study the nanobiointeractions of functionalized nanoparticles with amyloid aggregates. PMID:25486322

Caballero, Leonardo; Mena, Juan; Morales-Alvarez, Aurora; Kogan, Marcelo J; Melo, Francisco

2015-01-13

305

Identification of cellular and extracellular sites of amyloid precursor protein extracytoplasmic domain in normal and Alzheimer disease brains.  

OpenAIRE

Information concerning the distribution of various subdomains of the amyloid precursor protein (APP) in brain may illuminate aspects of the normal metabolism of this membrane-associated protein, as well as putative abnormal processing that may occur in Alzheimer disease (AD). We prepared affinity-purified antibody, P2, against an extracytoplasmic APP site and applied it, along with monoclonal antibodies to the beta-peptide, or A4 region, in conjunction with selective cytochemical staining met...

Tate-ostroff, B.; Majocha, R. E.; Marotta, C. A.

1989-01-01

306

Structures of segments of ?-synuclein fused to maltose-binding protein suggest intermediate states during amyloid formation  

OpenAIRE

Aggregates of the protein ?-synuclein are the main component of Lewy bodies, the hallmark of Parkinson's disease. ?-Synuclein aggregates are also found in many human neurodegenerative diseases known as synucleinopathies. In vivo, ?-synuclein associates with membranes and adopts ?-helical conformations. The details of how ?-synuclein converts from the functional native state to amyloid aggregates remain unknown. In this study, we use maltose-binding protein (MBP) as a carrier to crystalli...

Zhao, Minglei; Cascio, Duilio; Sawaya, Michael R.; Eisenberg, David

2011-01-01

307

Wnt1 inducible signaling pathway protein 1 (WISP1) targets PRAS40 to govern ?-amyloid apoptotic injury of microglia  

OpenAIRE

Given the present challenges to attain effective treatment for ?-amyloid (A?) toxicity in neurodegenerative disorders such as Alzheimer’s disease, development of novel cytoprotective pathways that can assist immune mediated therapies through the preservation of central nervous system microglia could offer significant promise. We show that the CCN4 protein, Wnt1 inducible signaling pathway protein 1 (WISP1), is initially up-regulated by A? and can modulate its endogenous expression for th...

Shang, Yan Chen; Chong, Zhao Zhong; Wang, Shaohui; Maiese, Kenneth

2012-01-01

308

Expression of the C terminus of the amyloid precursor protein alters growth factor responsiveness in stably transfected PC12 cells.  

OpenAIRE

The amyloid precursor protein (APP) is a molecule centrally involved in Alzheimer disease pathology, but whose normal function is still poorly understood. To investigate the consequences of increased intracellular production of various regions of APP on cellular physiology, we stably transfected PC12 cells with the C-terminal 100 amino acids of the human APP. In eight transfected clones that express the APP(C100) protein, exposure to nerve growth factor (NGF) did not promote differentiation. ...

Sandhu, F. A.; Kim, Y.; Lapan, K. A.; Salim, M.; Aliuddin, V.; Zain, S. B.

1996-01-01

309

SorLA CR-Domains Protect the Amyloid Precursor Protein against Processing  

DEFF Research Database (Denmark)

SorLA is a neuronal sorting receptor that is genetically associated with Alzheimer's disease. SorLA interacts directly with the amyloid precursor protein (APP) and affects the processing of the precursor, leading to a decreased generation of the amyloid-? (A?) peptide. The sorLA complement-type repeat (CR)-domains associate in vitro with APP, but the precise molecular determinants of sorLA-APP complex formation and the mechanisms responsible for the effect of binding on APP processing have not yet been elucidated. Here, we have generated protein expression constructs for sorLA devoid of the 11 CR-domains and for two sorLA mutants harboring substitutions of the fingerprint residues in the central CR-domains. We generated SH-SY5Y cell lines that stably express these sorLA variants to study the binding and processing of APP using co-immunoprecipitation and western blotting/ELISA assays, respectively. We found that the sorLA CR-cluster is essential for interaction with APP and that deletion of the CR-cluster abolishes the protection against APP processing. Mutation of identified fingerprint residues in the sorLA CR-domains leads to changes in the O-linked glycosylation of APP when expressed in SH-SY5Y cells. Our results provide novel information on the mechanisms behind the influence of sorLA activity on APP metabolism by controlling post-translational glycosylation in the Golgi, suggesting new strategies against amyloidogenesis in Alzheimer's disease.

Mehmedbasic, Arnela; Christensen, Sofie K

2014-01-01

310

The inhalation anesthetic isoflurane induces a vicious cycle of apoptosis and amyloid beta-protein accumulation.  

Science.gov (United States)

The anesthetic isoflurane has been reported to induce apoptosis and increase Abeta generation and aggregation. However, the molecular mechanism underlying these effects remains unknown. We therefore set out to assess whether the effects of isoflurane on apoptosis are linked to amyloid beta-protein (Abeta) generation and aggregation. For this purpose, we assessed the effects of isoflurane on beta-site amyloid beta precursor protein (APP)-cleaving enzyme (BACE) and gamma-secretase, the proteases responsible for Abeta generation. We also tested the effects of inhibitors of Abeta aggregation (iAbeta5, a beta-sheet breaker peptide; clioquinol, a copper-zinc chelator) on the ability of isoflurane to induce apoptosis. All of these studies were performed on naive human H4 neuroglioma cells as well as those overexpressing APP (H4-APP cells). Isoflurane increased the levels of BACE and gamma-secretase and secreted Abeta in the H4-APP cells. Isoflurane-induced Abeta generation could be blocked by the broad-based caspase inhibitor Z-VAD. The Abeta aggregation inhibitors, iAbeta5 and clioquinol, selectively attenuated caspase-3 activation induced by isoflurane. However, isoflurane was able to induce caspase-3 activation in the absence of any detectable alterations of Abeta generation in naive H4 cells. Finally, Abeta potentiated the isoflurane-induced caspase-3 activation in naive H4 cells. Collectively, these findings suggest that isoflurane can induce apoptosis, which, in turn, increases BACE and gamma-secretase levels and Abeta secretion. Isoflurane also promotes Abeta aggregation. Accumulation of aggregated Abeta in the media can then promote apoptosis. The result is a vicious cycle of isoflurane-induced apoptosis, Abeta generation and aggregation, and additional rounds of apoptosis, leading to cell death. PMID:17287498

Xie, Zhongcong; Dong, Yuanlin; Maeda, Uta; Moir, Robert D; Xia, Weiming; Culley, Deborah J; Crosby, Gregory; Tanzi, Rudolph E

2007-02-01

311

Amyloid precursor protein regulates migration and metalloproteinase gene expression in prostate cancer cells.  

Science.gov (United States)

Amyloid precursor protein (APP) is a type I transmembrane protein, and one of its processed forms, ?-amyloid, is considered to play a central role in the development of Alzheimer's disease. We previously showed that APP is a primary androgen-responsive gene in prostate cancer and that its increased expression is correlated with poor prognosis for patients with prostate cancer. APP has also been implicated in several human malignancies. Nevertheless, the mechanism underlying the pro-proliferative effects of APP on cancers is still not well-understood. In the present study, we explored a pathophysiological role for APP in prostate cancer cells using siRNA targeting APP (siAPP). The proliferation and migration of LNCaP and DU145 prostate cancer cells were significantly suppressed by siAPP. Differentially expressed genes in siAPP-treated cells compared to control siRNA-treated cells were identified by microarray analysis. Notably, several metalloproteinase genes, such as ADAM10 and ADAM17, and epithelial-mesenchymal transition (EMT)-related genes, such as VIM, and SNAI2, were downregulated in siAPP-treated cells as compared to control cells. The expression of these genes was upregulated in LNCaP cells stably expressing APP when compared with control cells. APP-overexpressing LNCaP cells exhibited enhanced migration in comparison to control cells. These results suggest that APP may contribute to the proliferation and migration of prostate cancer cells by modulating the expression of metalloproteinase and EMT-related genes. PMID:25218471

Miyazaki, Toshiaki; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Inoue, Satoshi

2014-09-26

312

SorLA Complement-type Repeat Domains Protect the Amyloid Precursor Protein against Processing.  

Science.gov (United States)

SorLA is a neuronal sorting receptor that is genetically associated with Alzheimer disease. SorLA interacts directly with the amyloid precursor protein (APP) and affects the processing of the precursor, leading to a decreased generation of the amyloid-? peptide. The SorLA complement-type repeat (CR) domains associate in vitro with APP, but the precise molecular determinants of SorLA·APP complex formation and the mechanisms responsible for the effect of binding on APP processing have not yet been elucidated. Here, we have generated protein expression constructs for SorLA devoid of the 11 CR-domains and for two SorLA mutants harboring substitutions of the fingerprint residues in the central CR-domains. We generated SH-SY5Y cell lines that stably express these SorLA variants to study the binding and processing of APP using co-immunoprecipitation and Western blotting/ELISAs, respectively. We found that the SorLA CR-cluster is essential for interaction with APP and that deletion of the CR-cluster abolishes the protection against APP processing. Mutation of identified fingerprint residues in the SorLA CR-domains leads to changes in the O-linked glycosylation of APP when expressed in SH-SY5Y cells. Our results provide novel information on the mechanisms behind the influence of SorLA activity on APP metabolism by controlling post-translational glycosylation in the Golgi, suggesting new strategies against amyloidogenesis in Alzheimer disease. PMID:25525276

Mehmedbasic, Arnela; Christensen, Sofie K; Nilsson, Jonas; Rüetschi, Ulla; Gustafsen, Camilla; Poulsen, Annemarie Svane Aavild; Rasmussen, Rikke W; Fjorback, Anja N; Larson, Göran; Andersen, Olav M

2015-02-01

313

Significant association between renal function and amyloid-positive area in renal biopsy specimens in AL amyloidosis  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The kidney is a major target organ for systemic amyloidosis that often affects the kidney including proteinura, and elevated serum creatinine (Cr. The correlation between amount of amyloid deposits and clinical parameters is not known. The aim of this study was to clarify correlation the amyloid area in all renal biopsy specimen and clinical parameters. Methods Fifty-eight patients with an established diagnosis of AL amyloidosis participated in the study. All patients showed amyloid deposits in renal biopsies. We retrospectively investigated the correlation between clinical data and amyloid occupied area in whole renal biopsy specimens. Results The area occupied by amyloid was less than 10% in 57 of the 58 patients, and was under 2% in 40. For statistical analyses, %amyloid-positive areas were transformed to common logarithmic values (Log10%amyloid. Cr showed significant correlation with Log10%amyloid and estimated glomerular filtration rate (eGFR showed the significant negative correlation. Patient age, cleatinine clearance (Ccr, blood urea nitorogen, and urinary protein was not significantly correlated with Log10%amyloid. The correlation with other clinical factors such as sex, and serum concentrations of total protein, albumin, immunoglobulins, compliments was evaluated. None of these factors significantly correlated with Log10%amyloid. According to sex- and age- adjusted multiple linear regression analysis, Log10%amyloid had significant positive association with Cr and significant negative association with eGFR. Conclusion There is significant association between amyloid-positive area in renal tissue and renal function, especially Cr and eGFR. The level of Cr and eGFR may be a marker of amount of amyloid in renal tissue.

Kuroda Takeshi

2012-09-01

314

Mechanism of Neuronal versus Endothelial Cell Uptake of Alzheimer's Disease Amyloid ? Protein  

Science.gov (United States)

Alzheimer's disease (AD) is characterized by significant neurodegeneration in the cortex and hippocampus; intraneuronal tangles of hyperphosphorylated tau protein; and accumulation of ?-amyloid (A?) proteins 40 and 42 in the brain parenchyma as well as in the cerebral vasculature. The current understanding that AD is initiated by the neuronal accumulation of A? proteins due to their inefficient clearance at the blood-brain-barrier (BBB), places the neurovascular unit at the epicenter of AD pathophysiology. The objective of this study is to investigate cellular mechanisms mediating the internalization of A? proteins in the principle constituents of the neurovascular unit, neurons and BBB endothelial cells. Laser confocal micrographs of wild type (WT) mouse brain slices treated with fluorescein labeled A?40 (F-A?40) demonstrated selective accumulation of the protein in a subpopulation of cortical and hippocampal neurons via nonsaturable, energy independent, and nonendocytotic pathways. This groundbreaking finding, which challenges the conventional belief that A? proteins are internalized by neurons via receptor mediated endocytosis, was verified in differentiated PC12 cells and rat primary hippocampal (RPH) neurons through laser confocal microscopy and flow cytometry studies. Microscopy studies have demonstrated that a significant proportion of F-A?40 or F-A?42 internalized by differentiated PC12 cells or RPH neurons is located outside of the endosomal or lysosomal compartments, which may accumulate without degradation. In contrast, BBME cells exhibit energy dependent uptake of F-A?40, and accumulate the protein in acidic cell organelle, indicative of endocytotic uptake. Such a phenomenal difference in the internalization of A?40 between neurons and BBB endothelial cells may provide essential clues to understanding how various cells can differentially regulate A? proteins and help explain the vulnerability of cortical and hippocampal neurons to A? toxicity. PMID:19247480

Kandimalla, Karunya K.; Scott, Olenych G.; Fulzele, Smita; Davidson, Michael W.; Poduslo, Joseph F.

2009-01-01

315

MD-simulations of Beta-Amyloid Protein Insertion Efficiency and Kinetics into Neuronal Membrane Mimics  

Science.gov (United States)

Early interaction events of beta-amyloid (A?) peptides with the neuronal membranes play a key role in the pathogenesis of Alzheimer's disease. We have used all-atom MD simulations to study the protein insertion efficiency and kinetics of monomeric A?40 and A?42 into phosphatidylcholine lipid bilayers (PC) with and without 40 mole% cholesterol (CHOL) that mimic the cholesterol-enriched and depleted lipid nanodomains of the neuronal plasma membranes. Independent replicates of 200-ns simulations of each protein pre-inserted in the upper lipid layer were generated. In PC bilayers, only 25% of A?40 and 50% of A?42 in the replicates showed complete insertion into the lower lipid layer, whereas the percentages increased to 50% and 100%, respectively, in PC/CHOL bilayers, providing evidence that cholesterol improves the protein insertion efficiency into the bilayers. The rate of protein insertion was proportional to the hydrophobic, transmembrane helix length of the inserted peptide and depended on the cholesterol content. We propose that the lysine snorkeling and C-terminus anchoring of A? to the PC headgroups at the upper and lower lipid/water interfaces represent the dual-transmembrane stabilization mechanisms of A? in the neuronal membrane domains.

Qiu, Liming; Buie, Creighton; Vaughn, Mark; Cheng, Kwan

2011-03-01

316

Serum proteins, trace metals and phosphatases in psoriasis  

Directory of Open Access Journals (Sweden)

Full Text Available Serum proteins, zinc, copper, acid phosphatase (AcPase and alkaline phosphatase (AlPase were studied in both active and remission phases of psoriasis. Data were compared with healthy controls, ?1, ? and ? globulins were high in active phase while ?1 and ? globulins were at par in remission phase. Serum copper was low but zinc and alkaline phosphatase were significantly high in both active and remission phases of the disease. Acid phosphatase level was at par in all the experimental groups. Study suggests a positive correlation of globulin, zinc and Alpase in active and remission phase of psoriasis.

Bhatnagar M

1994-01-01

317

Effects of Methylthiouracil on the Serum Protein Fractions in Dog  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of a prolonged oral administration of methylthiouracil was studied on the electrophoretically - separated serum protein fractions in 24 dogs. Though the statistical mean of changes in serum albumin and alpha2 globulin were highly significant but the individual alterations were not consistent and therefore on the basis of the available data there does not seem to be a characteristic electrophoretic pattern in the experimentally produced hypothyroidism in the dog. This finding is in agreement with the clinical electrophoretic pattern reported in the human spontaneous hypothyroidism.

A- Pousti N- Guiti

1970-07-01

318

Nongradient blue native gel analysis of serum proteins and in-gel detection of serum esterase activities.  

Science.gov (United States)

The objective of the present study was to analyze serum protein complexes and detect serum esterase activities using nongradient blue native polyacrylamide gel electrophoresis (BN-PAGE). For analysis of potential protein complexes, serum from rat was used. Results demonstrate that a total of 8 gel bands could be clearly distinguished after Coomassie blue staining, and serum albumin could be isolated nearly as a pure protein. Moreover, proteins in these bands were identified by electrospray mass spectrometry and low-energy collision induced dissociation (CID)-MS/MS peptide sequencing and the existence of serum dihydrolipoamide dehydrogenase (DLDH) was confirmed. For studies of in-gel detection of esterase activities, serum from rat, mouse, and human was used. In-gel staining of esterase activity was achieved by the use of either ?-naphthylacetate or ?-naphthylacetate in the presence of Fast blue BB salt. There were three bands exhibiting esterase activities in the serum of both rat and mouse. In contrast, there was only one band showing esterase activity staining in the human serum. When serum samples were treated with varying concentrations of urea, esterase activity staining was abolished for all the bands except the one containing esterase 1 (Es1) protein that is known to be a single polypeptide enzyme, indicating that majority of these esterases were protein complexes or multimeric proteins. We also identified the human serum esterase as butyrylcholinesterase following isolation and partial purification using ammonium sulfate fractioning and ion exchange column chromatographies. Where applicable, demonstrations of the gel-based method for measuring serum esterase activities under physiological or pathophysiological conditions were illustrated. Results of the present study demonstrate that nongradient BN-PAGE can serve as a feasible analytical tool for proteomic and enzymatic analysis of serum proteins. PMID:21237726

Thangthaeng, Nopporn; Sumien, Nathalie; Forster, Michael J; Shah, Ruchir A; Yan, Liang-Jun

2011-02-15

319

Haptoglobin and serum amyloid A in relation to the somatic cell count in quarter, cow composite and bulk tank milk samples.  

Science.gov (United States)

Milk somatic cell count (SCC) is the gold standard in diagnosis of subclinical mastitis, and is also an important parameter in quality programmes of dairy cooperatives. As routine SCC analysis is usually restricted to central laboratories, much effort has been invested in the search for alternative biomarkers of mastitis and milk quality, including the presence in the milk of the acute phase proteins (APP), haptoglobin (Hp) and serum amyloid A (SAA). The aim of this study was to investigate relationships between Hp, SAA and SCC in quarter, cow composite, and bulk tank milk samples. Cows (n=165), without any clinical signs of disease or abnormalities in the milk or udder, from three different dairy farms, were used. Cow composite milk samples from all cows delivering milk at the sampling occasion were taken once in each herd. In one of the farms, representative quarter milk samples (n=103) from 26 cows were also collected. In addition, bulk tank milk samples from 96 dairy farms were included in the study. Samples were analysed for Hp, SAA and SCC, and relationships between the parameters were evaluated at quarter, cow and tank milk levels using Chi-square analysis. Milk samples were categorized according to their SCC, and the presence, or no presence, of SAA and Hp, based on the detection limits of the screening methods (0.3 mg/l and 1.0 mg/l for SAA and Hp, respectively). Hp and SAA were found in milk at quarter, cow composite and bulk tank levels. A large proportion (53%) of the animals had detectable milk concentrations of APP, and SAA was detected more frequently, and at higher concentrations than Hp, regardless of sample type. SAA was detected in as many as 82% of the bulk tank milk samples. Significant relationships were found between Hp, SAA and SCC at quarter and cow composite milk levels, but only between SAA and SCC at bulk tank milk level. Detectable levels of APP were more common at high SCC. PMID:17227596

Akerstedt, Maria; Persson Waller, Karin; Sternesjö, Ase

2007-05-01

320

Dynamic behavior of small heat shock protein inhibition on amyloid fibrillization of a small peptide (SSTSAA) from RNase A  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Mechanism of small heat shock protein inhibition on fibril formation was studied. Black-Right-Pointing-Pointer Peptide SSTSAA with modified ends was used for amyloid fibril formation. Black-Right-Pointing-Pointer FRET signal was followed during the fibril formation. Black-Right-Pointing-Pointer Mj HSP16.5 inhibits fibril formation when introduced in the lag phase. Black-Right-Pointing-Pointer Mj HSP16.5 slows down fibril formation when introduced after the lag phase. -- Abstract: Small heat shock proteins, a class of molecular chaperones, are reported to inhibit amyloid fibril formation in vitro, while the mechanism of inhibition remains unknown. In the present study, we investigated the mechanism by which Mj HSP16.5 inhibits amyloid fibril formation of a small peptide (SSTSAA) from RNase A. A model peptide (dansyl-SSTSAA-W) was designed by introducing a pair of fluorescence resonance energy transfer (FRET) probes into the peptide, allowing for the monitoring of fibril formation by this experimental model. Mj HSP16.5 completely inhibited fibril formation of the model peptide at a molar ratio of 1:120. The dynamic process of fibril formation, revealed by FRET, circular dichroism, and electron microscopy, showed a lag phase of about 2 h followed by a fast growth period. The effect of Mj HSP16.5 on amyloid fibril formation was investigated by adding it into the incubation solution during different growth phases. Adding Mj HSP16.5 to the incubating peptide before or during the lag phase completely inhibited fibril formation. However, introducing Mj HSP16.5 after the lag phase only slowed down the fibril formation process by adhering to the already formed fibrils. These findings provide insight into the inhibitory roles of small heat shock proteins on amyloid fibril formation at the molecular level.

Xi, Dong [BNLMS, State Key Laboratory of Structural Chemistry for Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Center for Theoretical Biology, Peking University, Beijing 100871 (China); Dong, Xiao; Deng, Wei [BNLMS, State Key Laboratory of Structural Chemistry for Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Lai, Luhua, E-mail: lhlai@pku.edu.cn [BNLMS, State Key Laboratory of Structural Chemistry for Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Center for Theoretical Biology, Peking University, Beijing 100871 (China)

2011-12-09

321

Dynamic behavior of small heat shock protein inhibition on amyloid fibrillization of a small peptide (SSTSAA) from RNase A  

International Nuclear Information System (INIS)

Highlights: ? Mechanism of small heat shock protein inhibition on fibril formation was studied. ? Peptide SSTSAA with modified ends was used for amyloid fibril formation. ? FRET signal was followed during the fibril formation. ? Mj HSP16.5 inhibits fibril formation when introduced in the lag phase. ? Mj HSP16.5 slows down fibril formation when introduced after the lag phase. -- Abstract: Small heat shock proteins, a class of molecular chaperones, are reported to inhibit amyloid fibril formation in vitro, while the mechanism of inhibition remains unknown. In the present study, we investigated the mechanism by which Mj HSP16.5 inhibits amyloid fibril formation of a small peptide (SSTSAA) from RNase A. A model peptide (dansyl-SSTSAA-W) was designed by introducing a pair of fluorescence resonance energy transfer (FRET) probes into the peptide, allowing for the monitoring of fibril formation by this experimental model. Mj HSP16.5 completely inhibited fibril formation of the model peptide at a molar ratio of 1:120. The dynamic process of fibril formation, revealed by FRET, circular dichroism, and electron microscopy, showed a lag phase of about 2 h followed by a fast growth period. The effect of Mj HSP16.5 on amyloid fibril formation was investigated by adding it into the incubation solution during different growth phases. Adding Mj HSP16.5 to the incubating peptide before or during the lag phase completely inhibited fibril formation. However, introducing Mj HSP16.5 after the lag phase only slowed down the fibril formation process by adhering to the already formed fibrils. These findings provide insight into the inhibitory roles of small heat shock proteins on amyloid fibril formation at the molecular level.

322

Amyloids here, amyloids there…What’s wrong with them?  

OpenAIRE

Amyloid formation is inherent property of proteins which under certain circumstances can become a pathologic feature of a group of diseases called amyloidosis. There are about 30 known human amyloidosis and more than 27 identified proteins involved in these pathologies.  Besides these proteins, there are a growing number of proteins non-related to diseases shown to form amyloid-like structures in vitro, which make them excellent tools for studying amyloid formation mechanisms, physicochemica...

Gharibyan, Anna

2012-01-01

323

Minocycline alleviates beta-amyloid protein and tau pathology via restraining neuroinflammation induced by diabetic metabolic disorder  

Directory of Open Access Journals (Sweden)

Full Text Available Zhiyou Cai,1 Yong Yan,2 Yonglong Wang2 1Department of Neurology, the Lu’an Affiliated Hospital of Anhui Medical University, Lu’an People’s Hospital, Lu’an, Anhui Province, People’s Republic of China; 2Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, People’s Republic of China Background: Compelling evidence has shown that diabetic metabolic disorder plays a critical role in the pathogenesis of Alzheimer’s disease, including increased expression of ?-amyloid protein (A? and tau protein. Evidence has supported that minocycline, a tetracycline derivative, protects against neuroinflammation induced by neurodegenerative disorders or cerebral ischemia. This study has evaluated minocycline influence on expression of A? protein, tau phosphorylation, and inflammatory cytokines (interleukin-1? and tumor necrosis factor-? in the brain of diabetic rats to clarify neuroprotection by minocycline under diabetic metabolic disorder. Method: An animal model of diabetes was established by high fat diet and intraperitoneal injection of streptozocin. In this study, we investigated the effect of minocycline on expression of A? protein, tau phosphorylation, and inflammatory cytokines (interleukin-1? and tumor necrosis factor-? in the hippocampus of diabetic rats via immunohistochemistry, western blotting, and enzyme-linked immunosorbent assay. Results: These results showed that minocycline decreased expression of A? protein and lowered the phosphorylation of tau protein, and retarded the proinflammatory cytokines, but not amyloid precursor protein. Conclusion: On the basis of the finding that minocycline had no influence on amyloid precursor protein and beta-site amyloid precursor protein cleaving enzyme 1 which determines the speed of A? generation, the decreases in A? production and tau hyperphosphorylation by minocycline are through inhibiting neuroinflammation, which contributes to A? production and tau hyperphosphorylation. Minocycline may also lower the self-perpetuating cycle between neuroinflammation and the pathogenesis of tau and A? to act as a neuroprotector. Therefore, the ability of minocycline to modulate inflammatory reactions may be of great importance in the selection of neuroprotective agents, especially in chronic conditions like diabetes and Alzheimer’s disease. Keywords: diabetes mellitus, minocycline, tau protein, ?-amyloid protein

Cai Z

2013-08-01

324

Intracerebroventricular Injection of Anti-Fas Activates the Hypothalamus-Pituitary-Adrenal Axis and Induces Peripheral Interleukin-6 and Serum Amyloid A in Mice : Comparison with Other Ligands of the Tumor Necrosis Factor/Nerve Growth Factor Receptor Superfamily  

OpenAIRE

Fas is a receptor of the tumor necrosis factor (TNF)/nerve growth factor (NGF) receptor superfamily that mediates apoptosis and some inflammatory changes. As the central administration of TNF is known to activate the hypothalamus-pituitary-adrenal axis (HPAA) and to induce peripheral responses including induction of serum interleukin (IL)-6 and serum amyloid A (SAA), we investigated the effects of intracerebroventricular (i.c.v.) administration of agonist anti-Fas monoclonal antibody Jo2. Cen...

Benigni, Fabio; Sacco, Silvano; Aloe, Luigi; Ghezzi, Pietro

1998-01-01

325

ATBF1 is a novel amyloid-? protein precursor (A?PP) binding protein that affects A?PP expression.  

Science.gov (United States)

The cytoplasmic C-terminal domain of amyloid-? protein precursor (A?PP) binds to several proteins that regulate the trafficking and processing of A?PP and affects amyloid-? (A?) production. We previously reported that levels of AT-motif binding factor 1 (ATBF1) are increased in the brains of 17-month-old Tg2576 mice compared with wild-type controls, and that A?42 increases ATBF1 expression, inducing death in primary rat cortical neurons. Here, we show that ATBF1 levels are increased in the cytoplasm of hippocampal neurons in Alzheimer's disease (AD) brains compared with non-AD brains. Furthermore, cotransfection of human embryonic kidney (HEK293T) and human neuroblastoma (SH-SY5Y) cells with ATBF1 and A?PP695 increased steady-state levels of A?PP via the binding of ATBF1 to the A?PP cytoplasmic domain (amino acids 666-690), resulting in increased A? production and cellular and soluble A?PP (sA?PP) levels without affecting the activity or levels of A?PP processing enzymes (?-, ?-, or ?-secretase). Conversely, knockdown of endogenous ATBF1 reduced levels of cellular A?PP, sA?PP, and A? in HEK293 cells overexpressing human A?PP695. Our findings provide insight into the dynamics of A?PP processing and A? production, and suggest that ATBF1 is a novel A?PP binding protein that may be a suitable therapeutic target for AD. PMID:25079792

Uhm, Kyung-Ok; Kim, Mi-Jeong; Kawaguchi, Makoto; Akatsu, Hiroyasu; Miura, Yutaka; Misumi, Sachiyo; Hida, Hideki; Choi, Eun-Kyoung; Kim, Yong-Sun; Michikawa, Makoto; Jung, Cha-Gyun

2015-01-01

326

Lead-Induced Accumulation of ?-Amyloid in the Choroid Plexus: Role of Low Density Lipoprotein Receptor Protein-1 and Protein Kinase C  

OpenAIRE

The choroid plexus (CP), constituting the blood–cerebrospinal fluid barrier, has the capacity to remove beta-amyloid (A?) from the cerebrospinal fluid. Our previous work indicates that exposure to lead (Pb) results in A? accumulation in the CP by decreasing the expression of low density lipoprotein receptor protein-1 (LRP1), a protein involved in the transport and clearance of A?. The current study was designed to explore the relationship between A? accumulation, protein kinase C (PKC) ...

Behl, Mamta; Zhang, Yanshu; Shi, Yunzhou; Cheng, Jixin; Du, Yansheng; Zheng, Wei

2010-01-01

327

Amyloid Beta Mediates Memory Formation  

Science.gov (United States)

The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid [beta] (1-42) peptide (A[beta][1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated,…

Garcia-Osta, Ana; Alberini, Cristina M.

2009-01-01

328

Giant multilevel cation channels formed by Alzheimer disease amyloid beta-protein [A beta P-(1-40)] in bilayer membranes.  

OpenAIRE

We have recently shown that the Alzheimer disease 40-residue amyloid beta-protein [A beta P-(1-40)] can form cation-selective channels when incorporated into planar lipid bilayers by fusion of liposomes containing the peptide. Since A beta P-(1-40) comprises portions of the putative extracellular and membrane-spanning domains of the amyloid precursor protein (APP751), we suggested that the channel-forming property could be the underlying cause of amyloid neurotoxicity. The peptide has been pr...

Arispe, N.; Pollard, H. B.; Rojas, E.

1993-01-01

329

The Drosophila Homologue of the Amyloid Precursor Protein Is a Conserved Modulator of Wnt PCP Signaling  

Science.gov (United States)

Wnt Planar Cell Polarity (PCP) signaling is a universal regulator of polarity in epithelial cells, but it regulates axon outgrowth in neurons, suggesting the existence of axonal modulators of Wnt-PCP activity. The Amyloid precursor proteins (APPs) are intensely investigated because of their link to Alzheimer's disease (AD). APP's in vivo function in the brain and the mechanisms underlying it remain unclear and controversial. Drosophila possesses a single APP homologue called APP Like, or APPL. APPL is expressed in all neurons throughout development, but has no established function in neuronal development. We therefore investigated the role of Drosophila APPL during brain development. We find that APPL is involved in the development of the Mushroom Body ?? neurons and, in particular, is required cell-autonomously for the ?-axons and non-cell autonomously for the ?-axons growth. Moreover, we find that APPL is a modulator of the Wnt-PCP pathway required for axonal outgrowth, but not cell polarity. Molecularly, both human APP and fly APPL form complexes with PCP receptors, thus suggesting that APPs are part of the membrane protein complex upstream of PCP signaling. Moreover, we show that APPL regulates PCP pathway activation by modulating the phosphorylation of the Wnt adaptor protein Dishevelled (Dsh) by Abelson kinase (Abl). Taken together our data suggest that APPL is the first example of a modulator of the Wnt-PCP pathway specifically required for axon outgrowth. PMID:23690751

Soldano, Alessia; Okray, Zeynep; Janovska, Pavlina; Tmejová, Kate?ina; Reynaud, Elodie; Claeys, Annelies; Yan, Jiekun; Atak, Zeynep Kalender; De Strooper, Bart; Dura, Jean-Maurice; Bryja, Vít?zslav; Hassan, Bassem A.

2013-01-01

330

Serum protein concentrations in calves with experimentally induced pneumonic pasteurellosis  

Directory of Open Access Journals (Sweden)

Full Text Available Ten healthy 2 to 4-week-old Holstein calves were randomly allotted into control and infected groups. Control calves (n=5 were inoculated intrabronchially with 5ml of Dulbecco's phosphate-buffered saline solution (DPBSS. Infected calves (n=5 were inoculated intrabronchially with 5x10(9 log-phase Mannheimia haemolytica organisms suspended in 5ml of DPBSS. Blood samples were obtained 15 minutes before and one, two, four and six hours after inoculation. Serum protein concentrations were determined by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Serum concentrations of proteins with molecular weights of 125,000 D (ceruloplasmin, 60,000 D (a 1-antitrypsin, 45,000 D (haptoglobin, and 40,000 D (acid glycoprotein were significantly increased in calves with pneumonic pasteurellosis, compared with concentrations in control calves. Results indicate that acute phase proteins increase more rapidly after the onset of inflammation than previously thought. Measurement of serum protein concentrations may be useful in monitoring the progression of the induced pneumonic pasteurellosis in calves.

Fagliari J.J.

2003-01-01

331

A proteomic reference map for pig serum proteins as a prerequisite for diagnostic applications.  

OpenAIRE

A reference protein map for pig serum was set up using two-dimensional electrophoresis (2-DE). Thirty-nine protein chains or spots deriving from 26 different proteins were identified by immunological and mass spectrometric methods. Thus, the positions of most medium to higher abundance serum proteins could be determined on the 2-DE gels. The plasma protein fibrinogen was also included in our study. The overall pig protein pattern differs in some respect to serum/plasma maps of other mammalian...

Miller, I.; Wait, R.; Sipos, W.; Gemeiner, M.

2009-01-01

332

Absence of Nitric Oxide Synthase 3 Increases Amyloid ?-Protein Pathology in Tg-5xFAD Mice  

Directory of Open Access Journals (Sweden)

Full Text Available Aim: The abnormal accumulation, assembly and deposition of the amyloid ?-protein (A? are prominent pathological features of patients with Alzheimer’s disease (AD and related disorders. A number of factors in the brain can influence A? accumulation and associated pathologies. The aim of the present study was to determine the consequences of deleting nitric oxide synthase (NOS 3, the endothelial form of NOS, in Tg-5xFAD mice, a model of parenchymal AD-like amyloid pathology. Methods: Tg-5xFAD mice were bred with NOS3-/- mice. Cohorts of Tg-5xFAD mice and bigenic Tg-5xFAD/NOS3-/- mice were aged to six months followed by collection of the blood and brain tissues from the mice for biochemical and pathological analyses. Results: ELISA analyses show that the absence of NOS3 results in elevated levels of cerebral and plasma A? peptides in Tg-5xFAD mice. Immunohistochemical analyses show that the absence of NOS3 increased the amount of parenchymal A? deposition and fibrillar amyloid accumulation in Tg-5xFAD mice. The elevated levels of A? were not due to changes in the expression levels of transgene encoded human amyloid precursor protein (APP, endogenous ?-secretase, or increased proteolytic processing of APP. Conclusions: The results from this study suggest that the loss of NOS3 activity enhances A? pathology in Tg-5xFAD mice. These findings are similar to previous studies of NOS2 deletion suggesting that reduced NOS activity and NO levels enhance amyloid-associated pathologies in human APP transgenic mice.

Zishuo Ian Hu

2013-06-01

333

Comparative transcriptome profiling of amyloid precursor protein family members in the adult cortex  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The ?-amyloid precursor protein (APP and the related ?-amyloid precursor-like proteins (APLPs undergo complex proteolytic processing giving rise to several fragments. Whereas it is well established that A? accumulation is a central trigger for Alzheimer's disease, the physiological role of APP family members and their diverse proteolytic products is still largely unknown. The secreted APPs? ectodomain has been shown to be involved in neuroprotection and synaptic plasticity. The ?-secretase-generated APP intracellular domain (AICD functions as a transcriptional regulator in heterologous reporter assays although its role for endogenous gene regulation has remained controversial. Results To gain further insight into the molecular changes associated with knockout phenotypes and to elucidate the physiological functions of APP family members including their proposed role as transcriptional regulators, we performed DNA microarray transcriptome profiling of prefrontal cortex of adult wild-type (WT, APP knockout (APP-/-, APLP2 knockout (APLP2-/- and APPs? knockin mice (APP?/? expressing solely the secreted APPs? ectodomain. Biological pathways affected by the lack of APP family members included neurogenesis, transcription, and kinase activity. Comparative analysis of transcriptome changes between mutant and wild-type mice, followed by qPCR validation, identified co-regulated gene sets. Interestingly, these included heat shock proteins and plasticity-related genes that were both down-regulated in knockout cortices. In contrast, we failed to detect significant differences in expression of previously proposed AICD target genes including Bace1, Kai1, Gsk3b, p53, Tip60, and Vglut2. Only Egfr was slightly up-regulated in APLP2-/- mice. Comparison of APP-/- and APP?/? with wild-type mice revealed a high proportion of co-regulated genes indicating an important role of the C-terminus for cellular signaling. Finally, comparison of APLP2-/- on different genetic backgrounds revealed that background-related transcriptome changes may dominate over changes due to the knockout of a single gene. Conclusion Shared transcriptome profiles corroborated closely related physiological functions of APP family members in the adult central nervous system. As expression of proposed AICD target genes was not altered in adult cortex, this may indicate that these genes are not affected by lack of APP under resting conditions or only in a small subset of cells.

Eils Roland

2011-03-01

334

Distinctive serum protein profiles involving abundant proteins in lung cancer patients based upon antibody microarray analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Cancer serum protein profiling by mass spectrometry has uncovered mass profiles that are potentially diagnostic for several common types of cancer. However, direct mass spectrometric profiling has a limited dynamic range and difficulties in providing the identification of the distinctive proteins. We hypothesized that distinctive profiles may result from the differential expression of relatively abundant serum proteins associated with the host response. Methods Eighty-four antibodies, targeting a wide range of serum proteins, were spotted onto nitrocellulose-coated microscope slides. The abundances of the corresponding proteins were measured in 80 serum samples, from 24 newly diagnosed subjects with lung cancer, 24 healthy controls, and 32 subjects with chronic obstructive pulmonary disease (COPD. Two-color rolling-circle amplification was used to measure protein abundance. Results Seven of the 84 antibodies gave a significant difference (p Conclusion Our results suggest that a distinctive serum protein profile involving abundant proteins may be observed in lung cancer patients relative to healthy subjects or patients with chronic disease and may have utility as part of strategies for detecting lung cancer.

Rom William N

2005-08-01

335

TUDCA, a bile acid, attenuates amyloid precursor protein processing and amyloid-? deposition in APP/PS1 mice.  

Science.gov (United States)

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by accumulation of amyloid-? (A?) peptide in the hippocampus and frontal cortex of the brain, leading to progressive cognitive decline. The endogenous bile acid tauroursodeoxycholic acid (TUDCA) is a strong neuroprotective agent in several experimental models of disease, including neuronal exposure to A?. Nevertheless, the therapeutic role of TUDCA in AD pathology has not yet been ascertained. Here we report that feeding APP/PS1 double-transgenic mice with diet containing 0.4 % TUDCA for 6 months reduced accumulation of A? deposits in the brain, markedly ameliorating memory deficits. This was accompanied by reduced glial activation and neuronal integrity loss in TUDCA-fed APP/PS1 mice compared to untreated APP/PS1 mice. Furthermore, TUDCA regulated lipid-metabolism mediators involved in A? production and accumulation in the brains of transgenic mice. Overall amyloidogenic APP processing was reduced with TUDCA treatment, in association with, but not limited to, modulation of ?-secretase activity. Consequently, a significant decrease in A?(1-40) and A?(1-42) levels was observed in both hippocampus and frontal cortex of TUDCA-treated APP/PS1 mice, suggesting that chronic feeding of TUDCA interferes with A? production, possibly through the regulation of lipid-metabolism mediators associated with APP processing. These results highlight TUDCA as a potential therapeutic strategy for the prevention and treatment of AD. PMID:22438081

Nunes, Ana F; Amaral, Joana D; Lo, Adrian C; Fonseca, Maria B; Viana, Ricardo J S; Callaerts-Vegh, Zsuzsanna; D'Hooge, Rudi; Rodrigues, Cecília M P

2012-06-01

336

Injury severity and serum amyloid A correlate with plasma oxidation-reduction potential in multi-trauma patients: a retrospective analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In critical injury, the occurrence of increased oxidative stress or a reduced antioxidant status has been observed. The purpose of this study was to correlate the degree of oxidative stress, by measuring the oxidation-reduction potential (ORP of plasma in the critically injured, with injury severity and serum amyloid A (SAA levels. Methods A total of 140 subjects were included in this retrospective study comprising 3 groups: healthy volunteers (N = 21, mild to moderate trauma (ISS Results ORP maxima were reached on day 3 (± 0.4 SEM and day 5 (± 0.5 SEM for the ISS Conclusion The results suggest the presence of an oxidative environment in the plasma of the critically injured as measured by ORP. More importantly, ORP can differentiate the degree of oxidative stress based on the severity of the trauma and degree of inflammation.

Mains Charles W

2009-11-01

337

Amyloid beta precursor protein and prion protein have a conserved interaction affecting cell adhesion and CNS development.  

Science.gov (United States)

Genetic and biochemical mechanisms linking onset or progression of Alzheimer Disease and prion diseases have been lacking and/or controversial, and their etiologies are often considered independent. Here we document a novel, conserved and specific genetic interaction between the proteins that underlie these diseases, amyloid-? precursor protein and prion protein, APP and PRP, respectively. Knockdown of APP and/or PRNP homologs in the zebrafish (appa, appb, prp1, and prp2) produces a dose-dependent phenotype characterized by systemic morphological defects, reduced cell adhesion and CNS cell death. This genetic interaction is surprisingly exclusive in that prp1 genetically interacts with zebrafish appa, but not with appb, and the zebrafish paralog prp2 fails to interact with appa. Intriguingly, appa & appb are largely redundant in early zebrafish development yet their abilities to rescue CNS cell death are differentially contingent on prp1 abundance. Delivery of human APP or mouse Prnp mRNAs rescue the phenotypes observed in app-prp-depleted zebrafish, highlighting the conserved nature of this interaction. Immunoprecipitation revealed that human APP and PrP(C) proteins can have a physical interaction. Our study reports a unique in vivo interdependence between APP and PRP loss-of-function, detailing a biochemical interaction that considerably expands the hypothesized roles of PRP in Alzheimer Disease. PMID:23236467

Kaiser, Darcy M; Acharya, Moulinath; Leighton, Patricia L A; Wang, Hao; Daude, Nathalie; Wohlgemuth, Serene; Shi, Beipei; Allison, W Ted

2012-01-01

338

Interaction of thorium with blood serum proteins in vivo  

International Nuclear Information System (INIS)

The distribution of thorium in the blood serum of rats was studied in vivo, using carrier-free 234Th and 59Fe-citrate solution. The chromatographic data presented in this short communication indicate that, as with plutonium, the iron-transport protein, transferrin, is the main carrier protein for thorium. Also, like plutonium, thorium could be displaced from the transferrin complex by excess iron. Further investigations are required to determine if plutonium and thorium are bound to the same sites on the transferrin molecule as iron and whether the binding mechanisms are similar. (U.K.)

339

Influence of anesthesia and surgery on the expression of transport receptors and catabolic enzymes of amyloid ?-protein in aged rats  

OpenAIRE

Objective?To investigate the expression changes in transport receptor and catabolic enzymes of amyloid ?-protein (A?) in the brain of aged rats after surgery. Methods?One hundred healthy SD rats were randomly divided into 4 groups according to their ages: aged control group (n=10), aged surgery group (n=40), young control group (n=10), and young surgery group (n=40). Rats in surgery group underwent hepatic lobectomy under anesthesia with 2% sevoflurane, followed by a 2-hour continuous a...

Liu, Yong-zhe; Gao, Ming-long; Ma, Li; Pan, Ning-ling; Ma, Ya-qun

2014-01-01

340

Structural Basis for Matrix Metalloproteinase-2 (MMP-2)-selective Inhibitory Action of ?-Amyloid Precursor Protein-derived Inhibitor*  

OpenAIRE

Unlike other synthetic or physiological inhibitors for matrix metalloproteinases (MMPs), the ?-amyloid precursor protein-derived inhibitory peptide (APP-IP) having an ISYGNDALMP sequence has a high selectivity toward MMP-2. Our previous study identified amino acid residues of MMP-2 essential for its selective inhibition by APP-IP and demonstrated that the N to C direction of the decapeptide inhibitor relative to the substrate-binding cleft of MMP-2 is opposite that of substrate. However, det...

Hashimoto, Hiroshi; Takeuchi, Tomoka; Komatsu, Kyoko; Miyazaki, Kaoru; Sato, Mamoru; Higashi, Shouichi

2011-01-01

341

Isolation and chemical characterization of Alzheimer's disease paired helical filament cytoskeletons: differentiation from amyloid plaque core protein  

OpenAIRE

The paired helical filaments (PHFs) of Alzheimer's disease were purified by a strategy in which the neurons and amyloid plaque cores of protein (APCP) were initially isolated. This was achieved by several steps of isocratic sucrose centrifugations of increasing molarity and a discontinuous isotonic Percoll density gradient. After collagenase elimination of contaminating blood vessels, lysis of neurons was produced by SDS treatment. The released PHF cytoskeletons were separated from contaminat...

1988-01-01

342

Genetic background changes the pattern of forebrain commissure defects in transgenic mice underexpressing the ?-amyloid-precursor protein  

OpenAIRE

We previously have reported corpus callosum defects in transgenic mice expressing the ?-amyloid precursor protein (?APP) with a deletion of exon 2 and at only 5% of normal levels. This finding indicates a possible involvement of ?APP in the regulation or guidance of axon growth during neural development. To determine to what degree the ?APP mutation interacts with genetic background alleles that predispose for forebrain commissure defects in some mouse lines, we have assessed the size of ...

Magara, Fulvio; Mu?ller, Ulrike; Li, Zhi-wei; Lipp, Hans-peter; Weissmann, Charles; Stagljar, Marijana; Wolfer, David P.

1999-01-01

343

Histone Deacetylase Inhibitor Valproic Acid Inhibits Cancer Cell Proliferation via Down-regulation of the Alzheimer Amyloid Precursor Protein*  

OpenAIRE

The ?-amyloid precursor protein (APP) represents a type I transmembrane glycoprotein that is ubiquitously expressed. In the brain, it is a key player in the molecular pathogenesis of Alzheimer disease. Its physiological function is however less well understood. Previous studies showed that APP is up-regulated in prostate, colon, pancreatic tumor, and oral squamous cell carcinoma. In this study, we show that APP has an essential role in growth control of pancreatic and colon cancer. Abundant ...

Venkataramani, Vivek; Rossner, Christian; Iffland, Lara; Schweyer, Stefan; Tamboli, Irfan Y.; Walter, Jochen; Wirths, Oliver; Bayer, Thomas A.

2010-01-01

344

Characterizing the location and trafficking routes of the neuronal retromer and its role in amyloid precursor protein transport  

OpenAIRE

The retromer complex plays an important role in intracellular transport, is highly expressed in the hippocampus, and has been implicated in the trafficking of the amyloid precursor protein (APP). Nevertheless, the trafficking routes of the neuronal retromer and the role it plays in APP transport in neuronal processes remains unknown. Here we use hippocampal neuronal cultures to address these issues. Using fluorescence microscopy, we find that Vps35, the core element of the retromer complex, i...

Bhalla, Akhil; Vetanovetz, Christopher P.; Morel, Etienne; Chamoun, Zeina; Paolo, Gilbert Di; Small, Scott A.

2012-01-01

345

Structures of segments of [alpha]-synuclein fused to maltose-binding protein suggest intermediate states during amyloid formation  

Energy Technology Data Exchange (ETDEWEB)

Aggregates of the protein {alpha}-synuclein are the main component of Lewy bodies, the hallmark of Parkinson's disease. {alpha}-Synuclein aggregates are also found in many human neurodegenerative diseases known as synucleinopathies. In vivo, {alpha}-synuclein associates with membranes and adopts {alpha}-helical conformations. The details of how {alpha}-synuclein converts from the functional native state to amyloid aggregates remain unknown. In this study, we use maltose-binding protein (MBP) as a carrier to crystallize segments of {alpha}-synuclein. From crystal structures of fusions between MBP and four segments of {alpha}-synuclein, we have been able to trace a virtual model of the first 72 residues of {alpha}-synuclein. Instead of a mostly {alpha}-helical conformation observed in the lipid environment, our crystal structures show {alpha}-helices only at residues 1-13 and 20-34. The remaining segments are extended loops or coils. All of the predicted fiber-forming segments based on the 3D profile method are in extended conformations. We further show that the MBP fusion proteins with fiber-forming segments from {alpha}-synuclein can also form fiber-like nano-crystals or amyloid-like fibrils. Our structures suggest intermediate states during amyloid formation of {alpha}-synuclein.

Zhao, Minglei; Cascio, Duilio; Sawaya, Michael R.; Eisenberg, David (UCLA)

2011-08-29

346

Structures of segments of ?-synuclein fused to maltose-binding protein suggest intermediate states during amyloid formation  

Science.gov (United States)

Aggregates of the protein ?-synuclein are the main component of Lewy bodies, the hallmark of Parkinson's disease. ?-Synuclein aggregates are also found in many human neurodegenerative diseases known as synucleinopathies. In vivo, ?-synuclein associates with membranes and adopts ?-helical conformations. The details of how ?-synuclein converts from the functional native state to amyloid aggregates remain unknown. In this study, we use maltose-binding protein (MBP) as a carrier to crystallize segments of ?-synuclein. From crystal structures of fusions between MBP and four segments of ?-synuclein, we have been able to trace a virtual model of the first 72 residues of ?-synuclein. Instead of a mostly ?-helical conformation observed in the lipid environment, our crystal structures show ?-helices only at residues 1–13 and 20–34. The remaining segments are extended loops or coils. All of the predicted fiber-forming segments based on the 3D profile method are in extended conformations. We further show that the MBP fusion proteins with fiber-forming segments from ?-synuclein can also form fiber-like nano-crystals or amyloid-like fibrils. Our structures suggest intermediate states during amyloid formation of ?-synuclein. PMID:21462277

Zhao, Minglei; Cascio, Duilio; Sawaya, Michael R; Eisenberg, David

2011-01-01

347

Protein binding and serum bactericidal activities of vancomycin and teicoplanin.  

Science.gov (United States)

In a randomized crossover study, the protein binding and serum bactericidal activities (SBAs) of vancomycin and teicoplanin against Staphylococcus aureus and Streptococcus pyogenes were investigated in six healthy volunteers. Total concentrations in serum 1 h postadministration of vancomycin and teicoplanin were 25.5 +/- 2.7 and 10.8 +/- 8.9 mg/liter, respectively; mean free concentrations were 14.6 +/- 2.0 and 0.6 +/- 0.9 mg/liter, respectively. Protein binding for vancomycin was 36.9% +/- 2.87%, and that for teicoplanin was 97.4% +/- 2.6%. SBA determined in pooled human serum at 1 h against S. aureus ranged from 1:8 to 1:32 for both vancomycin and teicoplanin. Against S. pyogenes SBA at 1 h ranged from 1:16 to 1:128 for vancomycin and 1:256 to 1:2,048 for teicoplanin. In vitro kill curve studies showed that vancomycin is slowly bactericidal and that teicoplanin is bacteriostatic. Despite having less in vitro cidal activity against the study isolates and having low or unrecordable levels of free drug in serum, teicoplanin demonstrated a similar or better SBA than vancomycin. SBA was more closely related to the total drug level (r = 0.77 for S. aureus and r = 0.79 for S. pyogenes) than the free level of teicoplanin (r = 0.59 for S. aureus and r = 0.56 for S. pyogenes). The high level of protein binding of teicoplanin did not seem to impair its antibacterial activity as measured by its SBA. PMID:7486929

Dykhuizen, R S; Harvey, G; Stephenson, N; Nathwani, D; Gould, I M

1995-01-01

348

Loss of functional albumin triggers acceleration of transthyretin amyloid fibril formation in familial amyloidotic polyneuropathy.  

Science.gov (United States)

Transthyretin (TTR)-related familial amyloidotic polyneuropathy (FAP) is characterized by systemic accumulation of amyloid fibrils caused by a point mutation in the TTR gene. Despite the urgent need for alternative therapeutic strategies, the pathogenesis of FAP still remains elusive. In our study reported here, we focused on albumin, the most abundant protein in plasma, and described the role of albumin in the TTR amyloid-formation process. Patients with FAP evidenced significantly decreased serum albumin levels as the disease progressed. Biacore analysis showed that albumin had a binding affinity for TTR and exhibited higher affinity for TTR amyloid than native TTR. Albumin functioning as an antioxidant effectively suppressed TTR amyloid formation. In patients with FAP, albumin was significantly oxidized as the disease progressed. Moreover, loss of functional albumin accelerated TTR deposition in analbuminemic rats possessing a human variant TTR gene. Taken together, these results indicate that albumin may have an inhibitory role in the TTR amyloid-formation process. PMID:21537325

Kugimiya, Tomoe; Jono, Hirofumi; Saito, Shiori; Maruyama, Toru; Kadowaki, Daisuke; Misumi, Yohei; Hoshii, Yoshinobu; Tasaki, Masayoshi; Su, Yu; Ueda, Mitsuharu; Obayashi, Konen; Shono, Makoto; Otagiri, Masaki; Ando, Yukio

2011-08-01

349

Serum protein markers for early detection of ovarian cancer.  

Science.gov (United States)

Early diagnosis of epithelial ovarian cancer (EOC) would significantly decrease the morbidity and mortality from this disease but is difficult in the absence of physical symptoms. Here, we report a blood test, based on the simultaneous quantization of four analytes (leptin, prolactin, osteopontin, and insulin-like growth factor-II), that can discriminate between disease-free and EOC patients, including patients diagnosed with stage I and II disease, with high efficiency (95%). Microarray analysis was used initially to determine the levels of 169 proteins in serum from 28 healthy women, 18 women newly diagnosed with EOC, and 40 women with recurrent disease. Evaluation of proteins that showed significant differences in expression between controls and cancer patients by ELISA assays yielded the four analytes. These four proteins then were evaluated in a blind cross-validation study by using an additional 106 healthy females and 100 patients with EOC (24 stage I/II and 76 stage III/IV). Upon sample decoding, the results were analyzed by using three different classification algorithms and a binary code methodology. The four-analyte test was further validated in a blind binary code study by using 40 additional serum samples from normal and EOC cancer patients. No single protein could completely distinguish the cancer group from the healthy controls. However, the combination of the four analytes exhibited the following: sensitivity 95%, positive predictive value (PPV) 95%, specificity 95%, and negative predictive value (NPV) 94%, a considerable improvement on current methodology. PMID:15890779

Mor, Gil; Visintin, Irene; Lai, Yinglei; Zhao, Hongyu; Schwartz, Peter; Rutherford, Thomas; Yue, Luo; Bray-Ward, Patricia; Ward, David C

2005-05-24

350

Curli functional amyloid systems are phylogenetically widespread and display large diversity in operon and protein structure  

DEFF Research Database (Denmark)

Escherichia coli and a few other members of the Enterobacteriales can produce functional amyloids known as curli. These extracellular fibrils are involved in biofilm formation and studies have shown that they may act as virulence factors during infections. It is not known whether curli fibrils are restricted to the Enterobacteriales or if they are phylogenetically widespread. The growing number of genome-sequenced bacteria spanning many phylogenetic groups allows a reliable bioinformatic investigation of the phylogenetic diversity of the curli system. Here we show that the curli system is phylogenetically much more widespread than initially assumed, spanning at least four phyla. Curli fibrils may consequently be encountered frequently in environmental as well as pathogenic biofilms, which was supported by identification of curli genes in public metagenomes from a diverse range of habitats. Identification and comparison of curli subunit (CsgA/B) homologs show that these proteins allow a high degree of freedom in their primary protein structure, although a modular structure of tightly spaced repeat regions containing conserved glutamine, asparagine and glycine residues has to be preserved. In addition, a high degree of variability within the operon structure of curli subunits between bacterial taxa suggests that the curli fibrils might have evolved to fulfill specific functions. Variations in the genetic organization of curli genes are also seen among different bacterial genera. This suggests that some genera may utilize alternative regulatory pathways for curli expression. Comparison of phylogenetic trees of Csg proteins and the 16S rRNA genes of the corresponding bacteria showed remarkably similar overall topography, suggesting that horizontal gene transfer is a minor player in the spreading of the curli system.

Dueholm, Morten S; Albertsen, Mads

2012-01-01

351

Overexpression of Mutant Amyloid-? Protein Precursor and Presenilin 1 Modulates Enteric Nervous System.  

Science.gov (United States)

Alzheimer's disease (AD) is a neurodegenerative disorder histologically characterized by amyloid-? (A?) protein accumulation and activation of associated microglia. Although these features are well described in the central nervous system, the process and consequences of A? accumulation in the enteric nervous system have not been extensively studied. We hypothesized that A? also may accumulate in the enteric nervous system and lead to immune cell activation and neuronal dysfunction in the digestive tract not unlike that observed in diseased brain. To test this hypothesis, ileums of the small intestine of thirteen month old A?PP/PS1 and C57BL/6 (wild type) mice were collected and analyzed using immunohistochemistry, western blot analysis, cytokine arrays, and ELISA. A?PP/PS1 mice demonstrated no differences in intestinal motility or water absorption but elevated luminal IgA levels compared to wild type mice. They also had increased protein levels of A?PP and the proteolytic enzyme, BACE, corresponding to an increase in A?1-40 in the intestinal lysate as well as an increase in both A?1-40 and A?1-42 in the stool. This correlated with increased protein markers of proinflammatory and immune cell activation. Histologic analysis localized A?PP within enteric neurons but also intestinal epithelial cells with elevated A? immunoreactivity in the A?PP/PS1 mice. The presence of A?PP, A?, and CD68 immunoreactivity in the intestines of some patients with neuropathologically-confirmed AD are consistent with the findings in this mouse model. These data support the hypothesis that in AD the intestine, much like the brain, may develop proinflammatory and immune changes related to A?PP and A?. PMID:25408221

Puig, Kendra L; Lutz, Brianna M; Urquhart, Siri A; Rebel, Andrew A; Zhou, Xudong; Manocha, Gunjan D; Sens, MaryAnn; Tuteja, Ashok K; Foster, Norman L; Combs, Colin K

2014-11-18

352

Glial expression of the {beta}-Amyloid Precursor Protein (APP) in global ischemia  

Energy Technology Data Exchange (ETDEWEB)

The {beta}-amyloid precursor protein (APP) bears characteristics of an acute-phase protein and therefore is likely to be involved in the glial response to brain injury. In the brain, APP is rapidly synthesized by activated glial cells in response to comparatively mild neuronal lesions, e.g., a remote peripheral nerve injury. Perfusion deficits in the brain result largely in neuronal necrosis and are a common condition in elderly patients. This neuronal necrosis is accompanied by a pronounced reaction of astrocytes and microglia, which can also be observed in animal models. We have therefore studied in the rat, immunocytochemically, the induction of APP after 30 min of global ischemia caused by four-vessel occlusion. The postischemic brain injuries were examined at survival times from 12 h to 7 days. From day 3 onward, APP immunoreactivity was strongly induced in the CA{sub 1} and CA{sub 4} regions of the rat dorsal hippocampus as well as in the dorsolateral striatum. In these areas, the majority of APP-immunoreactive cells were reactive glial fibrillary acidic protein (GFAP)-positive astrocytes, as shown by double-immunofluorescence labeling for GFAP and APP. Additionally, small ramified cells, most likely activated microglia, expressed APP immunoreactivity. In contrast, in the parietal cortex, APP immunoreactivity occurred focally in clusters of activated microglia rather than in astrocytes, as demonstrated by double-immunofluorescence labeling for APP and the microglia-binding lectin Griffonia simplicifolia isolectin B{sub 4}. In conclusion, following global ischemia, APP is induced in reactive glial cells with spatial differences in the distribution pattern of APP induction in actrocytes and microglia. 51 refs., 4 figs.

Banati, R.B.; Gehrmann, J.; Kreutzberg, G.W. [Max Planck Institute of Psychiarty, Martinsried (Germany)]|[Max Planck Institute for Neurological Research, Koeln (Germany)]|[Univ. Hospital, Zurich (Switzerland)

1995-07-01

353

Amyloid beta 42 peptide (A?42)-lowering compounds directly bind to A? and interfere with amyloid precursor protein (APP) transmembrane dimerization  

Science.gov (United States)

Following ectodomain shedding by ?-secretase, successive proteolytic cleavages within the transmembrane sequence (TMS) of the amyloid precursor protein (APP) catalyzed by ?-secretase result in the release of amyloid-? (A?) peptides of variable length. A? peptides with 42 amino acids appear to be the key pathogenic species in Alzheimer’s disease, as they are believed to initiate neuronal degeneration. Sulindac sulfide, which is known as a potent ?-secretase modulator (GSM), selectively reduces A?42 production in favor of shorter A? species, such as A?38. By studying APP–TMS dimerization we previously showed that an attenuated interaction similarly decreased A?42 levels and concomitantly increased A?38 levels. However, the precise molecular mechanism by which GSMs modulate A? production is still unclear. In this study, using a reporter gene-based dimerization assay, we found that APP–TMS dimers are destabilized by sulindac sulfide and related A?42-lowering compounds in a concentration-dependent manner. By surface plasmon resonance analysis and NMR spectroscopy, we show that sulindac sulfide and novel sulindac-derived compounds directly bind to the A? sequence. Strikingly, the attenuated APP–TMS interaction by GSMs correlated strongly with A?42-lowering activity and binding strength to the A? sequence. Molecular docking analyses suggest that certain GSMs bind to the GxxxG dimerization motif in the APP–TMS. We conclude that these GSMs decrease A?42 levels by modulating APP–TMS interactions. This effect specifically emphasizes the importance of the dimeric APP–TMS as a promising drug target in Alzheimer’s disease. PMID:20679249

Richter, Luise; Munter, Lisa-Marie; Ness, Julia; Hildebrand, Peter W.; Dasari, Muralidhar; Unterreitmeier, Stephanie; Bulic, Bruno; Beyermann, Michael; Gust, Ronald; Reif, Bernd; Weggen, Sascha; Langosch, Dieter; Multhaup, Gerd

2010-01-01

354

Binding of rat serum phosphorylcholine binding protein to platelets.  

Science.gov (United States)

Rat serum phosphorylcholine binding protein (PCBP), a normal component of rat serum, inhibits in vitro aggregation of rat, rabbit and human platelets by interacting with platelets. In the present study, we have demonstrated the calcium-dependent, specific and saturable binding of 125I-PCBP to rat, rabbit and human platelets. Scatchard analysis of the binding data reveal a class of specific high-affinity binding sites with Kd values of 45.2 +/- 14.9, 26.1 +/- 8.3 and 32.2 +/- 9.9 nM on rat, rabbit and human platelets, respectively. These platelets also expressed a high capacity for binding to 125I-PCBP. The binding of 125I-PCBP to platelets was calcium- and time-dependent, and could be inhibited by phosphorylcholine (IC50 = 5.6 microM). Occupation of these binding sites by PCBP may be responsible for inhibition of platelet aggregation. PMID:2364084

Randell, E; Mookerjea, S; Nagpurkar, A

1990-06-20

355

Micro-Imaging of Amyloid in Mice  

OpenAIRE

Scintigraphic imaging of radioiodinated serum amyloid P-component is a proven methodology for the clinical detection of peripheral amyloid deposits (Hawkins, et al., 1990). However, the inability to perform comparably high resolution studies in experimental animal models of amyloid disease has impacted not only basic studies into the pathogenesis of amyloidosis but also in the preclinical in vivo evaluation of potential anti-amyloid therapeutic agents. We have developed micro-imaging technolo...

Wall, Jonathan S.; Paulus, Michael J.; Gleason, Shaun; Gregor, Jens; Solomon, Alan; Kennel, Stephen J.

2006-01-01

356

Analysis of amyloid precursor protein mRNAs in skin fibroblasts in Down's syndrome.  

Science.gov (United States)

We examined amyloid precursor protein (APP) mRNAs expression in skin fibroblasts from Down's syndrome (DS) patients of different ages to determine the time of occurrence of abnormal splicing. The ratio of APP770 + 751 mRNA to APP695 mRNA (APP770 + 751/695) was significantly increased in the young DS group and adult DS group compared with the age-matched control groups (p < 0.01, p < 0.05), but no significant increase was observed in the aged DS group compared with the age-matched control group. These findings suggest that metabolic abnormalities of the APP gene occur at a very early stage of DS, at a mean age of about 5 years. Therefore, metabolic abnormalities of the APP gene are considered to appear at a very young age also Alzheimer's disease (AD). In this study, we confirmed that examination of the APP gene in skin fibroblasts might be useful for early diagnosis of AD. PMID:8866680

Urakami, K; Kataoka, J; Okada, A; Isoe, K; Wakutani, Y; Ji, Y; Adachi, Y; Ohno, K; Takahashi, K

1996-01-01

357

Leptin inhibits amyloid ?-protein degradation through decrease of neprilysin expression in primary cultured astrocytes.  

Science.gov (United States)

Pathogenesis of Alzheimer's disease (AD) is characterized by accumulation of extracellular deposits of amyloid ?-protein (A?) in the brain. The steady state level of A? in the brain is determined by the balance between its production and removal; the latter occurring through egress across blood and CSF barriers as well as A? degradation. The major A?-degrading enzymes in the brain are neprilysin (NEP) and insulin-degrading enzyme (IDE), which may promote A? deposition in patients with sporadic late-onset AD. Epidemiological studies have suggested an inverse relationship between the adipocytokine leptin levels and the onset of AD. However, the mechanisms underlying the relationship remain uncertain. We investigated whether leptin is associated with A? degradation by inducing NEP and IDE expression within primary cultured astrocytes. Leptin significantly decreased the expression of NEP but not IDE in a concentration- and time-dependent manner through the activation of extracellular signal-regulated kinase (ERK) in cultured rat astrocytes. Furthermore, leptin inhibited the degradation of exogenous A? in primary cultured astrocytes. These results suggest that leptin suppresses A? degradation by NEP through activation of ERK. PMID:24508800

Yamamoto, Naoki; Tanida, Mamoru; Ono, Yoko; Kasahara, Rika; Fujii, Yuko; Ohora, Kentaro; Suzuki, Kenji; Sobue, Kazuya

2014-02-28

358

Activated protein C inhibits amyloid ? production via promoting expression of ADAM-10.  

Science.gov (United States)

Inhibition of A? production and clearance of senile plaques have been considered as potential strategies in the treatment of Alzheimer's disease (AD). Activated protein C (APC) is an important factor in the anticoagulant system. However, whether APC can influence the condition of a chronic neurodegenerative process, such as that present in AD, is unknown. In this study, we found that administration of APC on AD Tg2576 mice significantly reduced amyloid ? production and helped to facilitate cognitive improvement. APC could also reduce levels of A?40 and A?42 produced in APPswe cells, an AD cell model. Further results demonstrated that APC did not change the levels of A?-degrading enzymes, insulin-degrading enzyme (IDE), or neprilysin (NEP). Next, we found that APC promoted sAPP? and CTF? release and inhibited sAPP? and CTF? release, thereby indicating that APC could regulate A? secretion by shifting APP processing from the amyloidogenic pathway toward the nonamyloidogenic pathway. Correspondingly, further study revealed that ADAM-10 expression was increased by APC, suggesting that APC inhibits A? secretion through stimulating activity of ?-secretase. These findings support the idea that APC could hold therapeutic potential in the treatment of AD. PMID:24333930

Li, Bing; Yu, Dawei; Xu, Zhiying

2014-01-30

359

The effect of zinc on amyloid ?-protein assembly and toxicity: A mechanistic investigation  

Science.gov (United States)

Neurotoxic assemblies of amyloid ?-protein (A?) are widely believed to be the cause for Alzheimer's disease (AD). Therefore, understanding the factors and mechanisms that control, modulate, and inhibit formation of these assemblies is crucial for the development of therapeutic intervention of AD. This information also can contribute significantly to our understanding of the mechanisms of other amyloidosis diseases, such as Parkinson's disease, Huntington's disease, type 2 diabetes, amyotrophic lateral sclerosis (Lou Gehrig's disease) and prion diseases (e.g. Mad Cow disease). We have developed a multidisciplinary experimental strategy to study structural and dynamic mechanistic aspects that underlie the A? assembly process. Utilizing this strategy, we explored the molecular basis leading to the perturbation of the A? assembly process by divalent metal ions, mainly Zn2+ ions. Using Zn2+ as reaction physiological relevant probes, it was demonstrated that Zn2+ rapidly (milliseconds) induce self-assembly of A? aggregates and stabilize them in a manner that prevents formation of A? fibrils. Importantly, the early-formed intermediates are substantially more neurotoxic than fibrils. Our results suggest that relevant A? modulators should be targeted against the rapidly evolved intermediate states of A? assembly. The design of such modulators is challenging, as they have to compete with different natural mediators (such as Zn2+) of A? aggregation, which diverse A? assemblies in both specific and nonspecific manners.

Solomonov, Inna; Sagi, Irit

2014-10-01

360

Lead-induced morphological changes and amyloid precursor protein accumulation in adult rat hippocampus.  

Science.gov (United States)

Lead is an important environmental pollutant that exerts potent toxic effects on many organs. The toxic effects of lead are less well known for adult brain than for children. We investigated the morphological changes and amyloid precursor protein (APP) accumulation in the adult rat hippocampus following exposure to lead. Forty rats were divided into two groups of 20. One group was exposed to 580 parts per million (ppm) lead acetate and other group to an identical concentration of sodium acetate as a control group. After exposure to lead for 3 months, the hippocampus was examined by electron microscopy and APP levels in the hippocampus were detected using immunohistochemistry. Lead levels in the blood of rats exposed to lead were significantly higher than in the controls. The morphological changes in the hippocampus included mitochondrial degeneration, apoptosis and abnormal synapses in the rats exposed to lead. APP in hippocampus was increased significantly in the group exposed to lead compared to controls. We determined that lead exposure causes accumulation of APP and morphological changes in the adult rat hippocampus. PMID:24806610

Sun, Li; Zhou, Xie-Lai; Yi, Hong-Ping; Jiang, Su-Jun; Yuan, Hong

2014-10-01

361

Phenotypical difference of Amyloid Precursor Protein (APP V717L mutation in Japanese family  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Alzheimer’s disease (AD is the most common form of dementia. Mutations in genes such as those encoding amyloid precursor protein (APP, presenilin 1 and presenilin 2, are responsible for early-onset familial AD. Case presentation In this study, we report a 275341 G > C (Val717Leu mutation in the APP gene in a Japanese family with early onset AD by genetic screening. This mutation has previously been detected in European families. In the Japanese family we screened, the age at onset of AD was 47.1 ± 3.1 years old (n = 9; range, 42–52. The symptoms in the affected members included psychiatric vulnerability and focal signs such as pyramidal signs, epileptic seizures, and myoclonic discharges. An MR imaging study showed relatively mild atrophic changes in the bilateral hippocampus and cerebral cortices in all affected members compared with their clinical presentations. Conclusion We conclude that the clinical features of Alzheimer’s disease can be different even when caused by the same mutation in the APP gene. Further clinical and genetic studies are required to clarify the relationship between phenotypes and genotypes.

Abe Masao

2012-06-01

362

A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins  

Science.gov (United States)

A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the deposition of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in ?-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.

Li, Yang; Maurer, Jürgen; Roth, Andreas; Vogel, Vitali; Winter, Ernst; Mäntele, Werner

2014-08-01

363

Estrogen receptor ? promotes non-amyloidogenic processing of platelet amyloid precursor protein via the MAPK/ERK pathway.  

Science.gov (United States)

Deposition of amyloid ? peptide (A?), a proteolytic product of amyloid precursor protein (APP), in senile plaques and in the walls of cerebral blood vessels is a hallmark of Alzheimer's disease (AD). Platelets contain high levels of APP and A? and may contribute to amyloid deposits seen in AD. However, the biochemical mechanism(s) involved in the regulation of platelet APP metabolism are largely unknown. The estrogen receptor ? (ER?) is found to be expressed in platelets. It has not been elucidated whether ER?-mediated non-genomic signaling intervenes with platelet APP processing. Using ER? knock-out (?-ERKO) mice and wild type (WT) littermates, the present study demonstrated that ER?-specific agonist propylpyrazole triol (PPT) promoted non-amyloidogenic processing of platelet APP via the mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinase (ERK) pathway. The underlying basis involves direct association of activated ERK with a disintegrin and metalloprotease domain 17 (ADAM17, an ?-secretase candidate) and ERK-dependent threonine phosphorylation of ADAM17. These results suggest that selective modulation of ER? in peripheral target tissues may serve as an anti-amyloidogenic strategy for AD and other amyloidogenic diseases. PMID:25017047

Shi, Chun; Zhu, XiaoMing; Wang, Jisheng; Long, Dahong

2014-10-01

364

Experimentally derived structural constraints for amyloid fibrils of wild-type transthyretin.  

Science.gov (United States)

Transthyretin (TTR) is a largely ?-sheet serum protein responsible for transporting thyroxine and vitamin A. TTR is found in amyloid deposits of patients with senile systemic amyloidosis. TTR mutants lead to familial amyloidotic polyneuropathy and familial amyloid cardiomyopathy, with an earlier age of onset. Studies of amyloid fibrils of familial amyloidotic polyneuropathy mutant TTR suggest a structure similar to the native state with only a simple opening of a ?-strand-loop-strand region exposing the two main ?-sheets of the protein for fibril elongation. However, we find that the wild-type TTR sequence forms amyloid fibrils that are considerably different from the previously suggested amyloid structure. Using protease digestion with mass spectrometry, we observe the amyloid core to be primarily composed of the C-terminal region, starting around residue 50. Solid-state NMR measurements prove that TTR differs from other pathological amyloids in not having an in-register parallel ?-sheet architecture. We also find that the TTR amyloid is incapable of binding thyroxine as monitored by either isothermal calorimetry or 1,8-anilinonaphthalene sulfonate competition. Taken together, our experiments are consistent with a significantly different configuration of the ?-sheets compared to the previously suggested structure. PMID:22098747

Bateman, David A; Tycko, Robert; Wickner, Reed B

2011-11-16

365

Molecular mechanisms of Alzheimer disease protection by the A673T allele of amyloid precursor protein.  

Science.gov (United States)

Pathogenic mutations in the amyloid precursor protein (APP) gene have been described as causing early onset familial Alzheimer disease (AD). We recently identified a rare APP variant encoding an alanine-to-threonine substitution at residue 673 (A673T) that confers protection against development of AD (Jonsson, T., Atwal, J. K., Steinberg, S., Snaedal, J., Jonsson, P. V., Bjornsson, S., Stefansson, H., Sulem, P., Gudbjartsson, D., Maloney, J., Hoyte, K., Gustafson, A., Liu, Y., Lu, Y., Bhangale, T., Graham, R. R., Huttenlocher, J., Bjornsdottir, G., Andreassen, O. A., Jönsson, E. G., Palotie, A., Behrens, T. W., Magnusson, O. T., Kong, A., Thorsteinsdottir, U., Watts, R. J., and Stefansson, K. (2012) Nature 488, 96-99). The Ala-673 residue lies within the ?-secretase recognition sequence and is part of the amyloid-? (A?) peptide cleavage product (position 2 of A?). We previously demonstrated that the A673T substitution makes APP a less favorable substrate for cleavage by BACE1. In follow-up studies, we confirm that A673T APP shows reduced cleavage by BACE1 in transfected mouse primary neurons and in isogenic human induced pluripotent stem cell-derived neurons. Using a biochemical approach, we show that the A673T substitution modulates the catalytic turnover rate (V(max)) of APP by the BACE1 enzyme, without affecting the affinity (K(m)) of the APP substrate for BACE1. We also show a reduced level of A?(1-42) aggregation with A2T A? peptides, an observation not conserved in A?(1-40) peptides. When combined in a ratio of 1:9 A?(1-42)/A?(1-40) to mimic physiologically relevant mixtures, A2T retains a trend toward slowed aggregation kinetics. Microglial uptake of the mutant A?(1-42) peptides correlated with their aggregation level. Cytotoxicity of the mutant A? peptides was not dramatically altered. Taken together, our findings demonstrate that A673T, a protective allele of APP, reproducibly reduces amyloidogenic processing of APP and also mildly decreases A? aggregation. These effects could together have an additive or even synergistic impact on the risk of developing AD. PMID:25253696

Maloney, Janice A; Bainbridge, Travis; Gustafson, Amy; Zhang, Shuo; Kyauk, Roxanne; Steiner, Pascal; van der Brug, Marcel; Liu, Yichin; Ernst, James A; Watts, Ryan J; Atwal, Jasvinder K

2014-11-01

366

Effects of cerebrovascular disease on amyloid precursor protein metabolites in cerebrospinal fluid  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Alzheimer's disease (AD and cerebrovascular disease (CVD including chronic small vessel disease of the brain (SVD are the most frequent causes of dementia. AD is associated with metabolism of amyloid precursor protein (APP and low levels of amyloid-? peptide (A? X-42 in the cerebrospinal fluid (CSF. CVD and SVD are established risk factors for AD, brain white matter lesions (WML are established surrogate markers for SVD and are also associated with reduced CSF A?X-42. A cohort survey was performed to examine whether SVD or acute CVD affects APP metabolism and to explore a potential association between WML and APP metabolism in two groups; cognitively impaired patients, subjective and mild (SCI and MCI and stroke patients. Through measurements of CSF APP metabolite levels in patients with a wide range of WML volumes, this study aimed to determine how SVD influences APP metabolism. Methods Sixty-three patients were included: 37 with subjective cognitive impairment (SCI or mild cognitive impairment (MCI without stroke, and 26 after acute stroke. Chronic and acute WML volume and infarct volume were determined by magnetic resonance imaging (MRI post-scan processing, and CSF levels of ?- and ?-cleaved soluble APP (sAPP-? and sAPP-?, A?X-38, A?X-40 and A?X-42 were determined. The Mann-Whitney test was used to compare the patient groups. Chronic and acute WML volumes, infarct volume, age, and sex were used as predictors for CSF biomarker levels in linear regression analysis. Results CSF levels of sAPP-? and sAPP-? were strongly correlated (r = 0.95, p p p p ? 0.005; p ? 0.01; p ? 0.01; p ? 0.05; p ? 0.05 respectively, but not with acute WML or infarct volumes. Conclusions Lower CSF levels of sAPP-? and sAPP-? in the stroke group than in the SCI/MCI group and an inverse correlation with chronic WML indicate that ischemia lowers the levels of CSF sAPP metabolites and suggests that APP axonal transport or metabolism may be affected in SVD of the brain.

Rosengren Lars

2010-07-01

367

LRRTM3 promotes processing of amyloid-precursor protein by BACE1 and is a positional candidate gene for late-onset Alzheimer's disease  

OpenAIRE

Rare familial forms of Alzheimer's disease (AD) are thought to be caused by elevated proteolytic production of the A?42 peptide from the ?-amyloid-precursor protein (APP). Although the pathogenesis of the more common late-onset AD (LOAD) is not understood, BACE1, the protease that cleaves APP to generate the N terminus of A?42, is more active in patients with LOAD, suggesting that increased amyloid production processing might also contribute to the sporadic disease. Using high-throughput s...

Majercak, John; Ray, William J.; Espeseth, Amy; Simon, Adam; Shi, Xiao-ping; Wolffe, Carrie; Getty, Krista; Marine, Shane; Stec, Erica; Ferrer, Marc; Strulovici, Berta; Bartz, Steven; Gates, Adam; Xu, Min; Huang, Qian

2006-01-01

368

Amyloid formation: interface influence  

OpenAIRE

The causes of pathological conditions such as Alzheimer’s and Parkinson’s diseases are becoming better understood. Proteins that misfold from their native structure to form aggregates of ?-sheet fibrils — termed amyloid — are known1,2 to be implicated in these ‘amyloid diseases’. Understanding the early steps of fibril formation is critical, and the conditions, mechanism and kinetics of protein and peptide aggregation are being widely investigated...

Hamley, Ian W.

2010-01-01

369

Nanomaterials: amyloids reflect their brighter side  

Directory of Open Access Journals (Sweden)

Full Text Available Amyloid fibrils belong to the group of ordered nanostructures that are self-assembled from a wide range of polypeptides/proteins. Amyloids are highly rigid structures possessing a high mechanical strength. Although amyloids have been implicated in the pathogenesis of several human diseases, growing evidence indicates that amyloids may also perform native functions in host organisms. Discovery of such amyloids, referred to as functional amyloids, highlight their possible use in designing novel nanostructure materials. This review summarizes recent advances in the application of amyloids for the development of nanomaterials and prospective applications of such materials in nanotechnology and biomedicine.

Shruti Mankar

2011-05-01

370

Amyloidogenic processing of Alzheimer's amyloid precursor protein in vitro and its modulation by metal ions and tacrine.  

Science.gov (United States)

Recent studies implicate that excessive amyloidogenic pathway of amyloid precursor protein (APP) processing may be the final common pathway involved in the pathogensis of AD. In attempts to identify the proteases or factors leading to excessive amyloid deposition, we evaluated the potential role of acethylcholinesterase (AChE) and its associated protease for amyloidogenic processing of APP in vitro. Prolonged incubation of a recombinant APP770 with AChE produced several amyloidogenic fragments accumulating a relatively stable a 18 kDa A beta (amyloid beta-protein) bearing carboxy terminal peptide, which was further degraded by an increased concentration of AChE. Protease inhibitory profiles confirmed the trypsin-like serine protease activity present in AChE preparation. This observed APP processing was significantly enhanced by Ca2+, Mg2+, or Mn2+ at 1 mM concentration and modulated in concentration dependent manners by metal ions such as Ca2+, Zn2+, Fe2+/Fe3+, Al3+, or a tacrine, a centrally active cholinesterase inhibitor. Our data imply that AChE and its associated protease may be involved in the generation a 18 kDa amyloidogenic peptide under certain physiological condition in vivo and that the gradual changes in their proteolytic activities or locations and the locally disturbed metal homeostasis could be factors associated with abnormal accumulation of APP, eventually leading to amyloid deposition in AD brain. In addition, zinc or tacrine treatment of AD patients with high dosage or in the long term may have effects on the process of amyloidogensis. PMID:8761343

Chong, Y H; Suh, Y H

1996-01-01

371

Human serum protein adsorption onto synthesis nano-hydroxyapatite.  

Science.gov (United States)

Adsorption of human serum proteins (Albumin and total protein) onto high purity synthesis nano-hydroxyapatite (HA), Ca??(PO?)?(OH)?, has been studied in a wide temperature range by UV-visible spectrophotometer. Adsorption isotherm is basically important to describe how solutes interact with adsorbent, and is critical in optimizing the use of adsorbent. In the present study, the experimental results were fitted to the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (DR) models to obtain the characteristic parameters of each model and square of the correlation coefficients (R²). According to the results, the DR isotherm model had the best agreement with the experimental data. The effect of temperature on adsorption of human serum proteins (HSP) onto the synthesized nano-HA was studied. The experimental results indicated that temperature increase generally causes an increase in the adsorption of HSP onto the nano-HA. This is basically due to the effect of temperature on the HSP activity and its diffusion rate on HA surfaces. PMID:22207482

Mohsen-Nia, M; Massah Bidgoli, M; Behrashi, M; Mohsen Nia, A

2012-02-01

372

Hacking the Code of Amyloid Formation: The Amyloid Stretch Hypothesis  

OpenAIRE

Many research efforts in the last years have been directed towards understanding the factors determining protein misfolding and amyloid formation. Protein stability and amino acid composition have been identified as the two major factors in vitro. The research of our group has been focused on understanding the relationship between amino acid sequence and amyloid formation. Our approach has been the design of simple model systems that reproduce the biophysical properties of natural amyloids. A...

Pastor, M. Teresa; Esteras-chopo, Alexandra; Serrano, Luis

2007-01-01

373

An unusual peptide conformation may precipitate amyloid formation in Alzheimer's disease: Application of solid-state NMR to the determination of protein secondary structure  

Energy Technology Data Exchange (ETDEWEB)

The formation of insoluble proteinaceous deposits is characteristic of many diseases which are collectively known as amyloidois. There is very little molecular-level structural information available regarding the amyloid deposits due to the fact that the constituent proteins are insoluble and noncrystalline. Therefore, traditional protein structure determination methods such as solution NMR and X-ray crystallography are not applicable. The authors report herein the application of the solid state NMR technique rotational resonance (R{sup 2}) to the accurate measurement of carbon-to-carbon distances in the amyloid formed from a synthetic fragment (H{sub 2}N-LeuMetValGlyGlyValIleAla-CO{sub 2}H) of the amyloid-forming protein of Alzheimer's disease (AD). This sequence has been implicated in the initiation of amyloid formation. Two distances measured by R{sup 2} indicate that an unusual structure, probably involving a cis amide bond, is present in the aggregated peptide amyloid. This structure is incompatible with the accepted models of fibril structure. A relationship between this structure and the stability of the amyloid is proposed.

Spencer, R.G.S. (Massachusetts Inst. of Tech., Cambridge (United States) National Institutes of Health, Baltimore, MD (United States)); Halverson, K.J.; Auger, M.; McDermott, A.E.; Griffin, R.G.; Lansbury, P.T. Jr. (Massachusetts Inst. of Tech., Cambridge (United States))

1991-10-29

374

The index herd with PMWS in Sweden: Presence of serum amyloid A, circovirus 2 viral load and antibody levels in healthy and PMWS-affected pigs  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Postweaning Multisystemic Wasting Syndrome (PMWS is an emerging disease in pigs of multifactorial origin, but associated to porcine circovirus type 2 (PCV2 infection. PMWS was first diagnosed in Sweden at a progeny test station that received pigs aged five weeks from 19 different nucleus herds on the day after weaning. The objective of this study was to examine, for the first time in an index outbreak of PMWS, the relationship between PCV2 virus, antibodies to PCV2 and serum amyloid a (SAA in sequentially collected serum samples from pigs with and without signs of PMWS. Methods Forty pigs of the last batch that entered the station at a mean age of 37.5 days were monitored for signs of PMWS during the first 55 days after arrival. Serum was collected on six occasions and analysed for presence of PCV2 DNA and antibodies to PCV2, as well as for levels of SAA. Results Four of the pigs (10% were concluded to have developed PMWS, with necropsy confirmation in three of them. These pigs displayed low levels of maternal antibodies to PCV2, more than 107 PCV2 viral DNA copies per ml serum and failed to mount a serological response to the virus. Starting between day 23 and 34 after arrival, an increase in PCV2 viral load was seen in all pigs, but PCV2 did not induce any SAA-response. Pigs that remained healthy seroconverted to PCV2 as the viral load was increased, regardless of initially having low or high levels of PCV2-antibodies. Conclusion In this index case of PMWS in Sweden, pigs affected by PMWS were not able to mount a relevant serum antibody response which contributed to the disease progression. The maximal PCV2 virus load was significantly higher and was also detected at an earlier stage in PMWS-affected pigs than in healthy pigs. However, a viral load above 107 PCV2 DNA copies per ml serum was also recorded in 18 out of 34 pigs without any clinical signs of PMWS, suggesting that these pigs were able to initiate a protective immune response to PCV2.

Allan Gordon

2009-03-01

375

Embryo culture in teratological surveillance and serum proteins in development. Progress report, 1979-1980  

Energy Technology Data Exchange (ETDEWEB)

Research progress for the period 1979-1980 is reported. The feasibility of using rat embryo cultures to test the teratogenic activity of serum was studied. The mechanisms regulating the synthesis of serum proteins were investigated. (ACR)

Klein, N.W.

1980-07-01

376

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

Science.gov (United States)

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 (sAPP?) released following ?-secretase cleavage. In contrast, C99, the ?-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 sAPP? production and increased A? 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

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

377

Neural stem cells isolated from amyloid precursor protein-mutated mice for drug discovery  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To develop an in vitro model based on neural stem cells derived from transgenic animals, to be used in the study of pathological mechanisms of Alzheimer’s disease and for testing new molecules. METHODS: Neural stem cells (NSCs were isolated from the subventricular zone of Wild type (Wt and Tg2576 mice. Primary and secondary neurosphere generation was studied, analysing population doubling and the cell yield per animal. Secondary neurospheres were dissociated and plated on MCM Gel Cultrex 2D and after 6 d in vitro (DIVs in mitogen withdrawal conditions, spontaneous differentiation was studied using specific neural markers (MAP2 and TuJ-1 for neurons, GFAP for astroglial cells and CNPase for oligodendrocytes. Gene expression pathways were analysed in secondary neurospheres, using the QIAGEN PCR array for neurogenesis, comparing the Tg2576 derived cell expression with the Wt cells. Proteins encoded by the altered genes were clustered using STRING web software. RESULTS: As revealed by 6E10 positive staining, all Tg2576 derived cells retain the expression of the human transgenic Amyloid Precursor Protein. Tg2576 derived primary neurospheres show a decrease in population doubling. Morphological analysis of differentiated NSCs reveals a decrease in MAP2- and an increase in GFAP-positive cells in Tg2576 derived cells. Analysing the branching of TuJ-1 positive cells, a clear decrease in neurite number and length is observed in Tg2576 cells. The gene expression neurogenesis pathway revealed 11 altered genes in Tg2576 NSCs compared to Wt. CONCLUSION: Tg2576 NSCs represent an appropriate AD in vitro model resembling some cellular alterations observed in vivo, both as stem and differentiated cells.

Vito Antonio Baldassarro

2013-01-01

378

Cerebrospinal fluid amyloid beta and tau protein: Biomarkers for Alzheimer's disease  

Directory of Open Access Journals (Sweden)

Full Text Available Background/Aim. Introduction of acetylcholine esterase inhibitors as a symptomatic treatment of Alzheimer's disease (AD has additionally highlighted the importance of diagnostic markers in cerebrospinal fluid (CSF for early AD diagnosis: low level of 42 amino acid form of amyloid-? peptide (A?42, and levels of tau protein (T-tau and phosphorylated tau protein (P-tau. The aim of this study was to diagnostic potential of CSF biomarkers T-tau, P-tau and A?42 as biochemical markers for AD. Methods. Lumbar puncture was performed in 63 patients with AD and 26 control subjects who passed orthopedic surgery. The Innotest, ELISA sandwich test (Innogenetics - Belgium was used for measuring the levels of T-tau, P-tau and A?42. Results. The patients and the control group did not differ in age, education and sex. Mean levels of CSF T-tau and P-tau were significantly higher in the patients with AD (p < 0.001 compared to the control group, in contrast to significantely lower CSF A?42 in AD group (p < 0.001. A significant progressive decrease of A?42, as well as significant progressive increase of T-tau and P-tau was found among AD subgroups (according to MMSE staging and controls. Conclusion. The obtained results suggest that these biomarkers may be supportive in the diagnosis of AD, especially in the early course of the disease and could be used in the routine clinical practice considering the approaching target therapeutics.

Mandi? Gorana

2008-01-01

379

Competitive protein adsorption to polymer surface from human serum  

DEFF Research Database (Denmark)

Surface modification by "soft" plasma polymerisation to obtain a hydrophilic and non-fouling polymer surface has been validated using radioactive labelling. Adsorption to unmodified and modified polymer surfaces, from both single protein and human serum solutions, has been investigated. By using different radioisotopes, albumin and Immunoglobulin G (IgG) adsorption has been monitored simultaneously during competitive adsorption processes, which to our knowledge has not been reported in the literature before. Results show that albumin and IgG adsorption is dependent on adsorption time and on the presence and concentration of other proteins in bulk solutions during adsorption. Generally, lower albumin and IgG adsorption was observed on the modified and more hydrophilic polymer surfaces, but otherwise the modified and unmodified polymer surfaces showed the same adsorption characteristics.

Holmberg, Maria; Jensen, Karin Bagger Stibius

2008-01-01

380

Amyloid precursor protein processing and A?42 deposition in a transgenic mouse model of?Alzheimer?disease  

Science.gov (United States)

The PDAPP transgenic mouse, which overexpresses human amyloid precursor protein (APP717V?F), has been shown to develop much of the pathology associated with Alzheimer disease. In this report, levels of APP and its amyloidogenic metabolites were measured in brain regions of transgenic mice between 4 and 18 months of age. While absolute levels of APP expression likely contribute to the rate of amyloid ?-peptide (A?) deposition, regionally specific factors also seem important, as homozygotic mice express APP levels in pathologically unaffected regions in excess of that measured in certain amyloid plaque-prone regions of heterozygotic mice. Regional levels of APP and APP-? were nearly constant at all ages, while A? levels dramatically and predictably increased in brain regions undergoing histochemically confirmed amyloidosis, most notably in the cortex and hippocampus. In hippocampus, A? concentrations increase 17-fold between the ages of 4 and 8 months, and by 18 months of age are over 500-fold that at 4 months, reaching an average level in excess of 20 nmol of A? per g of tissue. A?1–42 constitutes the vast majority of the depositing A? species. The similarities observed between the PDAPP mouse and human Alzheimer disease with regard to A?42 deposition occurring in a temporally and regionally specific fashion further validate the use of the model in understanding processes related to the disease. PMID:9037091

Johnson-Wood, K.; Lee, M.; Motter, R.; Hu, K.; Gordon, G.; Barbour, R.; Khan, K.; Gordon, M.; Tan, H.; Games, D.; Lieberburg, I.; Schenk, D.; Seubert, P.; McConlogue, L.

1997-01-01

381

Polyglutamine-rich suppressors of huntingtin toxicity act upstream of hsp70 and sti1 in spatial quality control of amyloid-like proteins  

OpenAIRE

Protein conformational maladies such as Huntington Disease are characterized by accumulation of intracellular and extracellular protein inclusions containing amyloid-like proteins. There is an inverse correlation between proteotoxicity and aggregation, so facilitated protein aggregation appears cytoprotective. To define mechanisms for protective protein aggregation, a screen for suppressors of nuclear huntingtin (Htt103Q) toxicity was conducted. Nuclear Htt103Q is highly toxic and less aggreg...

Wolfe, K. J.; Ren, H. Y.; Trepte, P.; Cyr, D. M.

2014-01-01

382

PB1-F2 Influenza A Virus Protein Adopts a ?-Sheet Conformation and Forms Amyloid Fibers in Membrane Environments  

Science.gov (United States)

The influenza A virus PB1-F2 protein, encoded by an alternative reading frame in the PB1 polymerase gene, displays a high sequence polymorphism and is reported to contribute to viral pathogenesis in a sequence-specific manner. To gain insights into the functions of PB1-F2, the molecular structure of several PB1-F2 variants produced in Escherichia coli was investigated in different environments. Circular dichroism spectroscopy shows that all variants have a random coil secondary structure in aqueous solution. When incubated in trifluoroethanol polar solvent, all PB1-F2 variants adopt an ?-helix-rich structure, whereas incubated in acetonitrile, a solvent of medium polarity mimicking the membrane environment, they display ?-sheet secondary structures. Incubated with asolectin liposomes and SDS micelles, PB1-F2 variants also acquire a ?-sheet structure. Dynamic light scattering revealed that the presence of ?-sheets is correlated with an oligomerization/aggregation of PB1-F2. Electron microscopy showed that PB1-F2 forms amorphous aggregates in acetonitrile. In contrast, at low concentrations of SDS, PB1-F2 variants exhibited various abilities to form fibers that were evidenced as amyloid fibers in a thioflavin T assay. Using a recombinant virus and its PB1-F2 knock-out mutant, we show that PB1-F2 also forms amyloid structures in infected cells. Functional membrane permeabilization assays revealed that the PB1-F2 variants can perforate membranes at nanomolar concentrations but with activities found to be sequence-dependent and not obviously correlated with their differential ability to form amyloid fibers. All of these observations suggest that PB1-F2 could be involved in physiological processes through different pathways, permeabilization of cellular membranes, and amyloid fiber formation. PMID:20172856

Chevalier, Christophe; Al Bazzal, Ali; Vidic, Jasmina; Février, Vincent; Bourdieu, Christiane; Bouguyon, Edwige; Le Goffic, Ronan; Vautherot, Jean-François; Bernard, Julie; Moudjou, Mohammed; Noinville, Sylvie; Chich, Jean-François; Da Costa, Bruno; Rezaei, Human; Delmas, Bernard

2010-01-01

383

The Flavanol (?)-Epigallocatechin 3-Gallate Inhibits Amyloid Formation by Islet Amyloid Polypeptide, Disaggregates Amyloid Fibrils and Protects Cultured Cells Against IAPP Induced Toxicity+  

OpenAIRE

Islet amyloid polypeptide (IAPP, amylin) is the major protein component of islet amyloid deposits associated with type 2 diabetes. The polypeptide lacks a well–defined structure in its monomeric state, but readily assembles to form amyloid. Amyloid fibrils formed from IAPP, intermediates generated in the assembly of IAPP amyloid, or both are toxic to ?-cells suggesting that islet amyloid formation may contribute to the pathology of type 2 diabetes. There are relatively few reported inhibit...

Meng, Fanling; Abedini, Andisheh; Plesner, Annette; Verchere, C. Bruce; Raleigh, Daniel P.

2010-01-01

384

Beta-amyloid precursor protein of Alzheimer disease occurs as 110- to 135-kilodalton membrane-associated proteins in neural and nonneural tissues.  

OpenAIRE

Progressive cerebral deposition of extracellular filaments composed of the beta-amyloid protein (beta AP) is a constant feature of Alzheimer disease (AD). Since the gene on chromosome 21 encoding the beta AP precursor (beta APP) is not known to be altered in AD, transcriptional or posttranslational changes may underlie accelerated beta AP deposition. Using two antibodies to the predicted carboxyl terminus of beta APP, we have identified the native beta APP in brain and nonneural human tissues...

Selkoe, D. J.; Podlisny, M. B.; Joachim, C. L.; Vickers, E. A.; Lee, G.; Fritz, L. C.; Oltersdorf, T.

1988-01-01

385

A disintegrin and metalloprotease 10 activity sheds the ectodomain of the amyloid precursor-like protein 2 and regulates protein expression in proximal tubule cells  

OpenAIRE

A disintegrin and metalloprotease 10 (ADAM10) is a zinc protease that mediates ectodomain shedding of numerous receptors including Notch and members of the amyloid precursor protein family (APP, APLP1, and APLP2). Ectodomain shedding frequently activates a process called regulated intramembrane proteolysis (RIP) that links cellular events with gene regulation. To characterize ADAM10 in kidney and in opossum kidney proximal tubule (OKP) cells, we performed indirect immunofluorescence microscop...

Cong, Rong; Li, Yuanli; Biemesderfer, Daniel

2011-01-01

386

[Amyloid ? protein suppresses hippocampal theta rhythm and induces behavioral disinhibition and spatial memory deficit in rats].  

Science.gov (United States)

Hippocampal neuronal network oscillation is closely related to the memory, anxiety and behavioral inhibition of mammalian. The cognitive decline and behavioral disinhibition in the patients with Alzheimer's disease (AD) may be relevant to amyloid ? protein (A?)-induced impairment in hippocampal neuronal cooperative activity. However, it is not well known whether intrahippocampal injection of A? could induce behavioral disinhibition and neuronal network disorder, as well as cognition decline in animals. In the present study, we observed the effects of intracerebral injection of A?(1-42) on the spatial memory and behavioral inhibition of rats by using Morris water maze and elevated plus-maze tests. Further, we analyzed hippocampal theta rhythm by recording hippocampal local field potential. The results showed that: (1) bilateral hippocampal injection of A?(1-42) reduced the anxious behavior of rats, with a significant behavioral disinhibition in the elevated plus-maze test, representing as an increase in the mean entering times and mean residence time in the open arm; (2) A?(1-42) injection resulted in a significant impairment of spatial memory in rats, with significantly increased mean escape latencies in hidden platform test; (3) A?(1-42) disrupted the induction of theta rhythm induced by tail pinch, with a significant reduction in the peak power, not the peak power frequency of the theta rhythm. These experimental results indicate that intrahippocampal injection of A?(1-42) can induce behavioral disinhibition and theta rhythm suppression, as well as spatial memory impairment in rats, which suggests that the cognition deficits and behavior impairments in AD are probably associated with the A?-induced disruption of hippocampal theta rhythm and consequent down-regulation of synaptic plasticity. PMID:24777399

Yue, Xing-Hua; Liu, Xiao-Jie; Wu, Mei-Na; Chen, Jin-Yuan; Qi, Jin-Shun

2014-04-25

387

Yolk sac endoderm: exclusive site of serum protein synthesis in the early chick embryo  

International Nuclear Information System (INIS)

In order to determine which cell type or types synthesized serum proteins, yolk sacs from 4-day chick embryos were manually separated into ectoderm, mesoderm, and endoderm and incubated in the presence of radioactive valine. Analysis of the incubation media by polyacrylamide gel electrophoresis as well as by immunoprecipitation showed that all serum proteins were synthesized exclusively by the cells of the endoderm. These included transferrin and three embryo-specific serum proteins: ?reverse arrowglobulin ?-globulin b, and prealbumin

388

?-Amyloid Precursor Protein Does Not Possess Ferroxidase Activity but Does Stabilize the Cell Surface Ferrous Iron Exporter Ferroportin  

OpenAIRE

Ceruloplasmin is a ferroxidase that interacts with ferroportin to export cellular iron, but is not expressed in neurons. We recently reported that the amyloid precursor protein (APP) is the analogous iron-exporting chaperone for neurons and other cells. The ferroxidase activity of APP has since been called into question. Using a triplex Fe2+ oxidation assay, we analyzed the activity of a soluble form of APP (sAPP?) within a buffer of physiological pH and anionic charge, and determined that i...

Wong, Bruce X.; Tsatsanis, Andrew; Lim, Linh Q.; Adlard, Paul A.; Bush, Ashley I.; Duce, James A.

2014-01-01

389

Partial Loss-of-Function Mutations in Insulin-Degrading Enzyme that Induce Diabetes also Impair Degradation of Amyloid ?-Protein  

OpenAIRE

The causes of cerebral accumulation of amyloid ?-protein (A?) in most cases of Alzheimer’s disease (AD) remain unknown. We recently found that homozygous deletion of the insulin-degrading enzyme (IDE) gene in mice results in an early and marked elevation of cerebral A?. Both genetic linkage and allelic association in the IDE region of chromosome 10 have been reported in families with late-onset AD. For IDE to remain a valid candidate gene for late-onset AD on functional grounds, it must ...

Farris, Wesley; Mansourian, Stefan; Leissring, Malcolm A.; Eckman, Elizabeth A.; Bertram, Lars; Eckman, Christopher B.; Tanzi, Rudolph E.; Selkoe, Dennis J.

2004-01-01

390

Identification and measurement of a folate-binding protein in human serum by radioimmunoassay  

International Nuclear Information System (INIS)

Antiserum raised in rabbits against the FBP obtained from CML cells, and the purified binder labeled with 125I, have been used for an RIA which can measure an immunologically similar protein in human serum. The concentration of the binding protein in normal serums ranged from 1.2 to 9.3 ng/ml, with a mean +- S.E.M. of 3.8 +- 0.4 ng/ml. Elevated values of the binder protein were measured in the serums from patients with folate deficiency, vitamin B12 deficiency, liver disease, uremia, myeloproliferative diseases, chronic lymphocytic leukemia, and various types of cancer and in the serum from pregnant women. The concentration of the binder protein and the capacity of the serum to specifically bind isotopically labeled PGA correlated poorly, indicating that the binding protein concentration and degree of saturation by endogenous serum folate vary independently in many instances

391

Nature of amyloid deposits in hypernephroma. Immunocytochemical studies in 2 cases associated with amyloid polyneuropathy.  

OpenAIRE

Two patients who presented with amyloid polyneuropathy were found to have an amyloid-positive hypernephroma. The amyloid extracted from the tumor of one patient was purified by gel filtration and found to immunoreact by immunodiffusion, only with antiserum against denatured lambda-type amyloid protein but not with antisera against denatured kappa amyloid, AA, or prealbumin. With the unlabeled immunoperoxidase method or immunofluorescence in combination with these specific antisera, it was sho...

Dalakas, M. C.; Fujihara, S.; Askanas, V.; Engel, W. K.; Glenner, G. G.

1984-01-01

392

Evaluation of an in-clinic Serum Amyloid A (SAA assay and assessment of the effects of storage on SAA samples  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background An in-clinic assay for equine serum amyloid A (SAA analysis, Equinostic EVA1, was evaluated for use in a clinical setting. Stability of SAA in serum samples was determined. Methods Intra- and inter- assay variation of the in-clinic method was determined. The in-clinic method (EVA1 results were compared to a reference method (Eiken LZ SAA with 62 patient samples. For samples with SAA concentrations within the assay range of EVA1 (10-270 mg/L, differences between the methods were evaluated in a difference plot. Linearity under dilution was evaluated in two samples. Stability of SAA in three serum pools stored at 4°C and approximately 22°C was evaluated with the reference method day 0, 1, 2, 4, 7, 17 and analysed with a two-way ANOVA. Results The imprecision (coefficient of variation, CV for the in-clinic method was acceptable at higher SAA concentrations with CV values of 7,3-12%, but poor at low SAA concentrations with CV values of 27% and 37% for intra- and inter-assay variation respectively. Recovery after dilution was 50-138%. The in-clinic assay and the reference method identified equally well horses with low (270 mg/L SAA concentrations. Within the assay range of the in-clinic method, 10-270 mg/L, the difference between the two methods was slightly higher than could be explained by the inherent imprecision of the assays. There were no significant changes of serum SAA concentrations during storage. Conclusions The in-clinic assay identified horses with SAA concentrations of 270 mg/L in a similar way as the reference method, and provided an estimate of the SAA concentration in the range of 10-270 mg/L. The imprecision of the in-clinic method was acceptable at high SAA concentrations but not at low concentrations. Dilution of samples gave inconsistent results. SAA was stable both at room temperature and refrigerated, and thus samples may be stored before analysis with the reference method.

Tvedten Harold

2010-02-01

393

Chemokines, macrophage inflammatory protein-2 and stromal cell-derived factor-1?, suppress amyloid ?-induced neurotoxicity  

International Nuclear Information System (INIS)

Alzheimer's disease (AD) is characterized by a progressive cognitive decline and accumulation of neurotoxic oligomeric peptides amyloid-? (A?). Although the molecular events are not entirely known, it has become evident that inflammation, environmental and other risk factors may play a causal, disruptive and/or protective role in the development of AD. The present study investigated the ability of the chemokines, macrophage inflammatory protein-2 (MIP-2) and stromal cell-derived factor-1? (SDF-1?), the respective ligands for chemokine receptors CXCR2 and CXCR4, to suppress A?-induced neurotoxicity in vitro and in vivo. Pretreatment with MIP-2 or SDF-1? significantly protected neurons from A?-induced dendritic regression and apoptosis in vitro through activation of Akt, ERK1/2 and maintenance of metalloproteinase ADAM17 especially with SDF-1?. Intra-cerebroventricular (ICV) injection of A? led to reduction in dendritic length and spine density of pyramidal neurons in the CA1 area of the hippocampus and increased oxidative damage 24 h following the exposure. The A?-induced morphometric changes of neurons and increase in biomarkers of oxidative damage, F2-isoprostanes, were significantly inhibited by pretreatment with the chemokines MIP-2 or SDF-1?. Additionally, MIP-2 or SDF-1? was able to suppress the aberrant mislocalization of p21-activated kinase (PAK), one of the proteins involved in the maintenance of dendritic spines. Furthermore, MIP-2 also protected neurons against A? neurotoxicity in CXCR2?/? mice, potentially through observed up regulation of CXCR1 mRNA. Understanding the neuroprotective potential of chemokines is crucial in defining the role for their employment during the early stages of neurodegeneration. -- Research highlights: ? Neuroprotective ability of the chemokines MIP2 and CXCL12 against A? toxicity. ? MIP-2 or CXCL12 prevented dendritic regression and apoptosis in vitro. ? Neuroprotection through activation of Akt, ERK1/2 and maintenance of ADAM17. ? Neuroprotection of hippocampal pyramidal neurons in vivo by MIP-2 or CXCL12. ? MIP-2 or CXCL12 prevent elevation of F2-Isoprostanes against A? treatment.

394