- Email: [email protected]
ANTI-N-TERMINAL ABETA MAB 3A1 PREFERENTIALLY RECOGNIZES ABETA AGGREGATES AND DOES NOT CROSS-REACT WITH APP
P1504
Poster Presentations: Wednesday, July 19, 2017
from 4 different groups of mice depending on the TBI paradigm and time point after TBI at which the brains were collected: 1) sacrificed at 24 hours after a 50 psi single blast treatment, 2) sacrificed at 3 weeks after a 50 psi single blast treatment, 3) sacrificed at 3 weeks after repeated blast treatment (6 blasts over two weeks), 4) sacrificed at 3 weeks following anesthesia (sham group). The isolated tau oligomers were analyzed biochemically via PK digestion, western blotting and seeding. Moreover, their toxicity, internalization and spreading were tested in cell culture. Results: Results show that the TBI brain-derived Tau samples resemble tau oligomeric strains in terms of PK digestion pattern and reactivity with tau oligomer monoclonal antibodies. In addition, some of the samples were found to be toxic, and express different internalization levels into SY5Y cells in culture. Conclusions: Results suggest that different TBI brain-derived Tau oligomeric-like strains contribute to the neuronal death observed after TBI. Future experiments will investigate the samples’ differential ability to induce cell toxicity and neurodegeneration in vitro and in vivo. Results hold substantial translational implications towards applying Tau-immunotherapy techniques to reduce the risk for late-life dementia.
P4-452
SERUM/GLUCOCORTICOID REGULATED KINASE 1 (SGK1), TAU PATHOLOGY AND COGNITIVE DYSFUNCTION IN HIGH-FATDIET-FED TAUOPATHY MODEL MICE
Montasir Elahi, Yumiko Motoi, Koichi Ishiguro, Nobutaka Hattori, Juntendo University School of Medicine, Tokyo, Japan. Contact e-mail: [email protected] Background: The risk of Alzheimer’s disease (AD) is higher in pa-
tients with type 2 diabetes mellitus (T2DM). The effect of high-fat diet (HFD) on tau pathology in mice models remains controversial. Here, we examined the effects of HFD induced T2DM on transgenic mice overexpressing 2N4R wild-type human tau (Tg601 mice). Methods: 10-month-old non-transgenic and Tg601 mice were fed high fat diet (35% fat) for 5 months (N ¼ 9, respectively). The glucose tolerance test (GTT), and intraperitoneal insulin tolerance test (ITT) were conducted at 12 months. The Morris water maze test (MWM) and elevated plus maze test (EPM) were performed at 15 months prior to sacrifice. Brain protein levels of phosphorylated tau, AKT, PI3K, GSK-3b, Cdk5, and p-38MAPK were measured using western blotting. Whole transcriptome microarrays were performed to identify the responsible molecules of the hippocampus (N ¼3). Stable wild-type 2N4R tau transfected SH-SY5Y cells were used to analyze the function of SGK1. Results: The GTT and ITT indicated that HFD-fed NTg and Tg601 mice showed abnormal glucose intolerance. In the MWM, HFD-treated Tg601 mice demonstrated longer escape latency and swimming distance than non-treated mice. In the EPM, HFD-treated Tg601 mice spent shorter time than non-treated Tg601 mice. The amount of insoluble tau and phosphorylated tau at PS396 were elevated in HFD-fed Tg601 mice while there was no difference in the protein level of phospho S9 GSK-3b, phospho Y216 GSK-3b, Cdk5 and p-38MAPK. After prolonged exposure, oligomeric tau species with ～140kDa were detected in HFD-fed Tg601 mice. The transcriptome microarray analysis revealed a 5 fold increase in SGK1 expression level in HFD-treated Tg601 mice compared to nontreated Tg601 mice. After transfection of SGK1 into stable tau cell lines, tau phosphorylation level increased at S396. Conclusions:
Our findings indicate that SGK1 would be involved in tau phosphorylation in the development of T2DM and AD.
P4-453
ON THE MECHANISM OF THE TAU R406W MUTATION
Neal J. Zondlo, Himal K. Ganguly, Michael B. Elbaum, University of Delaware, Newark, DE, USA. Contact e-mail: [email protected] Background: The tau-R406W mutation is observed to have a causative effective in neurodegeneration in human tauopathies, and is widely used to induce neurodegeneration in mouse models of Alzheimer’s disease. Despite its clinical importance and wide use in research, the mechanism by which the R406W mutation leads to tau aggregation and neurodegeneration is not understood. Methods: We tested a series of hypotheses for potential mechanisms of functional effects of tau-R406W mutation: (1) increased hydrophobicity; (2) increased tau phosphorylation via increased activity by the kinases cdk5, GSK-3b, and/or PKA; (3) increased tau phosphorylation through decreased phosphorylation by the phosphatases PP2A or PP2B; (4) conformational change via increased cis amide bond formation due to a cis-proline-aromatic interaction. A series of peptides derived from the tau C-terminal domain was synthesized, in non-phosphorylated form and with phosphorylation at Ser396, Ser400, Thr403, Ser404, and/or Ser409. In addition, peptides were synthesized with R406 changed to Trp or other aromatic amino acids. Peptides were characterized by NMR spectroscopy. Results: The R406W mutation did not increase phosphorylation by any kinase tested. Surprisingly, R406W led to increased dephosphorylation by PP2A, contrary to expectations. In contrast, the R406W mutation led to a substantial increase in cis amide bond at Ser404-Pro405, via a cis-proline-aromatic C-H/P interaction that significantly stabilizes the cis proline amide bond. A significant increase in cis amide bond was also observed upon Ser404 phosphorylation, with the effects further modulated by phosphorylation at other sites. Additional structural changes dependent on phosphorylation and/or tauR406W were observed and characterized by NMR. Conclusions: The phosphorylation-dependent proline isomerism Pin1 has been strongly implicated in tau aggregation and Alzheimer’s disease. These data suggest that tau phosphorylation is not directly increased by the R406W mutation. Instead, the data suggest induction of proline-405 cis amide bond formation and subsequent structural changes as a primary mechanism for the functional effects of the R406W mutation.
P4-454
ANTI-N-TERMINAL ABETA MAB 3A1 PREFERENTIALLY RECOGNIZES ABETA AGGREGATES AND DOES NOT CROSSREACT WITH APP
Jeffrey L. Frost1, James S. Foster2, Peggy Taylor1, Brian O’Nuallain1, 1 Biolegend Inc., Dedham, MA, USA; 2University of Tennessee Graduate School of Medicine, Knoxville, TN, USA. Contact e-mail: bonuallain@ biolegend.com Background: The murine anti-N-terminal Abeta monoclonal anti-
body (mAb) 3A1 was generated against dityrosine cross-linked Abeta1-40 protein species (CAPS). 3A1’s epitope comprises of Abeta’s first 15 amino acids, DAEFRHDSGYEVHHQ. The mAb has demonstrated activity in vivo by decreasing plaque burden
Poster Presentations: Wednesday, July 19, 2017
and increasing plasma Abeta in an APPswe/PS1DE9 transgenic mouse model of Alzheimer’s disease [Frost et al (2015) Neurobiol Aging. 36(12): 3187]. To better understand the mAb’s specificity for Abeta we established in vitro the antibody’s ability to recognize Abeta1-40 conformers (monomers, dimers, protofibrils), APP, and rodent Abeta. Methods: 3A1’s avidity for Abeta conformers, APP and rodent Abeta were determined using ELISA, and Western blot assays. Anti-N-terminal Abeta mAb, 6E10 [Kim et al. (1988) Neurosci. Res. Comm. 7:113], was used as positive control. Abeta conformers were generated as previously described [Welzel et al (2012) PLoS One. 7(11):e50317]. Results: MAb 3A1 had similar avidity for plate-immobilized Abeta1-40 conformers as mAb 6E10, with EC50 values in the sub nM range. Both antibodies had essentially no reactivity with rodent Abeta1-40. However, in contrast to 6E10, mAb 3A1 showed a strong preference for aggregated compared with monomeric Abeta1-40, and did not detect APP protein. Conclusions: The N-terminal Abeta reactive MAb 3A1 demonstrated novel specificity by preferentially targeting the aggregated peptide without cross-reacting with APP. This unique activity may be utilized in immunoassay(s) to advance current poor understanding on the role of Abeta species in Alzheimer’s disease.
P4-455
NEUROPROTECTIVE EFFECT OF CANNABINOID RECEPTORS IN NEUROINFLAMATION
Gemma Navarro Brugal1, Dasiel Borroto-Escuela2, Irene Reyes1, Edgar Angelats1, Jose Luis Labandeira3, Kjell Fuxe2, Rafael Franco1, 1University of Barcelona, Barcelona, Spain; 2Karolinska Institutet, Stockholm, Sweden; 3University of Santiago de Compostela, Santiago de Compostela, Spain. Contact e-mail: [email protected] Background: The hypothesis of direct interactions between pairs of
G-protein-coupled receptors relevant for CNS function, launched by Luigi Agnati and Kjell Fuxe, has been confirmed and is now widely accepted. Natural and synthetic cannabinoids target two types of G-protein-coupled receptors (GPCRs). Cannabinoid CB1 receptors, which are enriched in the CNS and cannabinoid CB2 receptors that are more abundant in peripheral tissues. Methods: Energy transfer techniques in HEK-293T cells to determine protein-protein interactions. Microglia primary cultures preparation. Different signaling methodology to detect cAMP, MAPK and Dinamyc Mass redistribution. Proximity Ligation Assay to detect protein-protein interaction in natural tissues. Results: Despite the moderate expression of CB2 receptors in brain, it has been demonstrated that CB1 and CB2 may for receptor heteromers (RHets) in the CNS. Therefore, natural or synthetic cannabinoids may act on CB1, CB2 and CB1 or CB2 containing heteromers. The research presented in this paper was undertaken to know whether these two receptors may be expressed in activated microglia. It is worth noting that current knowledge assumed that CB1 is more a neuronal than glial receptor whereas the opposite occurs for CB2. On the one hand, the expression of receptors and RHets is different in resting and activated microglia. Activation was assayed in the N9 cell line and in primary cultures of microglia using LPS and interferon gamma. On the other hand, the increase in CB1-CB2 RHets correlates with a potentiation of the effects of selective CB2 receptors. Our results show that the composition of cannabinoid receptors and RHets in resting microglia prevent microglia activation while
P1505
in conditions of microgliosis due to Parkinsonian conditions, cannabinoid agonist regulate microglial activation. Conclusions: The results indicate that pharmacological manipulation of cannabinoid receptors in conditions of neuroinflammation may have relevant benefits in conditions of neuroinflammation.
P4-456
TAU AND P53 IN ALZHEIMER’S DISEASE
Kathleen M. Farmer, Mariana Carretero-Murillo, Salome McAllen, Partha Sarkar, Rakez Kayed, University of Texas Medical Branch, Galveston, TX, USA. Contact e-mail: [email protected] Background: P53 acts as a master regulator of cell cycle control, apoptosis, and DNA repair. Tau has been proposed to play a role in DNA damage, which is one of the earliest pathological changes in Alzheimer’s disease (AD). As p53 becomes activated due to DNA damage, it may be possible that an interaction between tau and p53 occurs in the early stages of AD. In addition, tau oligomers have been found to develop toxic gain of function and are one of the major contributors to neuron death in AD. Tau oligomers may sequester and/or cause the aggregation of other proteins. Thus, we hypothesize that p53 may be sequestered by tau oligomers, inhibiting its function. Methods: We evaluated total p53, functional phospho-p53, and tau aggregation status in AD patients and Tg2576 mice using both commercial and novel antibodies with conformational epitopes common to oligomers of aggregated proteins. Results: We found that phospho-p53 levels are modulated in human AD brain in comparison to control brain. We also found that phospho-p53 colocalizes with tau oligomers in human AD brain, highlighting a potential overlap between DNA damage response and AD. Conclusions: Our findings suggest that tau oligomers may be interacting with p53 and causing a down regulation of functional p53 in AD. This may suggest that tau may be interacting in DNA damage response signaling and therefore affecting cell death. These results may have implications for a number of other neurodegenerative disorders. Therefore, further research is needed to understand the underlying signaling pathways of tau and p53 interaction.
P4-457
N-TRUNCATED AND PYROGLUTAMATEMODIFIED Ab ACCELERATES AGGREGATION OF a-SYNUCLEIN IN VITRO
Anja Schulze1, Janett K€oppen1, Michael Wermann1, Angelika H€ahnel2, Jessica Klehm2, Hans-Ulrich Demuth1, Stephan Schilling1 1 Fraunhofer Institute for Cell Therapy and Immunology, Halle, Germany; 2Fraunhofer IMWS, Halle, Germany. Contact e-mail: [email protected] Background: The aggregation and depositoion of misfolded a-synuclein and Ab represent hallmarks of Parkinson’s and Alzheimer’s disease, respectively. Interestingly, a-synuclein and Ab pathology are frequently observed in the same individual, leading to the hypothesis that both peptides mutually interact to facilitate neurodegeneration. Here, we studied the influence of Ab1-42 and pGluAb3-42 on the aggregation of a-synuclein in vitro. Methods: Human alpha-synuclein was recombinantly expressed in Escherichia coli and purified. Ab1-42 and pGlu- Ab3-42 were synthesized by solid phase synthesis. The aggregation of alpha-synuclein was investigated using Thioflavin-T fluorescence assay, atomic force (AFM)
Poster Presentations: Wednesday, July 19, 2017
from 4 different groups of mice depending on the TBI paradigm and time point after TBI at which the brains were collected: 1) sacrificed at 24 hours after a 50 psi single blast treatment, 2) sacrificed at 3 weeks after a 50 psi single blast treatment, 3) sacrificed at 3 weeks after repeated blast treatment (6 blasts over two weeks), 4) sacrificed at 3 weeks following anesthesia (sham group). The isolated tau oligomers were analyzed biochemically via PK digestion, western blotting and seeding. Moreover, their toxicity, internalization and spreading were tested in cell culture. Results: Results show that the TBI brain-derived Tau samples resemble tau oligomeric strains in terms of PK digestion pattern and reactivity with tau oligomer monoclonal antibodies. In addition, some of the samples were found to be toxic, and express different internalization levels into SY5Y cells in culture. Conclusions: Results suggest that different TBI brain-derived Tau oligomeric-like strains contribute to the neuronal death observed after TBI. Future experiments will investigate the samples’ differential ability to induce cell toxicity and neurodegeneration in vitro and in vivo. Results hold substantial translational implications towards applying Tau-immunotherapy techniques to reduce the risk for late-life dementia.
P4-452
SERUM/GLUCOCORTICOID REGULATED KINASE 1 (SGK1), TAU PATHOLOGY AND COGNITIVE DYSFUNCTION IN HIGH-FATDIET-FED TAUOPATHY MODEL MICE
Montasir Elahi, Yumiko Motoi, Koichi Ishiguro, Nobutaka Hattori, Juntendo University School of Medicine, Tokyo, Japan. Contact e-mail: [email protected] Background: The risk of Alzheimer’s disease (AD) is higher in pa-
tients with type 2 diabetes mellitus (T2DM). The effect of high-fat diet (HFD) on tau pathology in mice models remains controversial. Here, we examined the effects of HFD induced T2DM on transgenic mice overexpressing 2N4R wild-type human tau (Tg601 mice). Methods: 10-month-old non-transgenic and Tg601 mice were fed high fat diet (35% fat) for 5 months (N ¼ 9, respectively). The glucose tolerance test (GTT), and intraperitoneal insulin tolerance test (ITT) were conducted at 12 months. The Morris water maze test (MWM) and elevated plus maze test (EPM) were performed at 15 months prior to sacrifice. Brain protein levels of phosphorylated tau, AKT, PI3K, GSK-3b, Cdk5, and p-38MAPK were measured using western blotting. Whole transcriptome microarrays were performed to identify the responsible molecules of the hippocampus (N ¼3). Stable wild-type 2N4R tau transfected SH-SY5Y cells were used to analyze the function of SGK1. Results: The GTT and ITT indicated that HFD-fed NTg and Tg601 mice showed abnormal glucose intolerance. In the MWM, HFD-treated Tg601 mice demonstrated longer escape latency and swimming distance than non-treated mice. In the EPM, HFD-treated Tg601 mice spent shorter time than non-treated Tg601 mice. The amount of insoluble tau and phosphorylated tau at PS396 were elevated in HFD-fed Tg601 mice while there was no difference in the protein level of phospho S9 GSK-3b, phospho Y216 GSK-3b, Cdk5 and p-38MAPK. After prolonged exposure, oligomeric tau species with ～140kDa were detected in HFD-fed Tg601 mice. The transcriptome microarray analysis revealed a 5 fold increase in SGK1 expression level in HFD-treated Tg601 mice compared to nontreated Tg601 mice. After transfection of SGK1 into stable tau cell lines, tau phosphorylation level increased at S396. Conclusions:
Our findings indicate that SGK1 would be involved in tau phosphorylation in the development of T2DM and AD.
P4-453
ON THE MECHANISM OF THE TAU R406W MUTATION
Neal J. Zondlo, Himal K. Ganguly, Michael B. Elbaum, University of Delaware, Newark, DE, USA. Contact e-mail: [email protected] Background: The tau-R406W mutation is observed to have a causative effective in neurodegeneration in human tauopathies, and is widely used to induce neurodegeneration in mouse models of Alzheimer’s disease. Despite its clinical importance and wide use in research, the mechanism by which the R406W mutation leads to tau aggregation and neurodegeneration is not understood. Methods: We tested a series of hypotheses for potential mechanisms of functional effects of tau-R406W mutation: (1) increased hydrophobicity; (2) increased tau phosphorylation via increased activity by the kinases cdk5, GSK-3b, and/or PKA; (3) increased tau phosphorylation through decreased phosphorylation by the phosphatases PP2A or PP2B; (4) conformational change via increased cis amide bond formation due to a cis-proline-aromatic interaction. A series of peptides derived from the tau C-terminal domain was synthesized, in non-phosphorylated form and with phosphorylation at Ser396, Ser400, Thr403, Ser404, and/or Ser409. In addition, peptides were synthesized with R406 changed to Trp or other aromatic amino acids. Peptides were characterized by NMR spectroscopy. Results: The R406W mutation did not increase phosphorylation by any kinase tested. Surprisingly, R406W led to increased dephosphorylation by PP2A, contrary to expectations. In contrast, the R406W mutation led to a substantial increase in cis amide bond at Ser404-Pro405, via a cis-proline-aromatic C-H/P interaction that significantly stabilizes the cis proline amide bond. A significant increase in cis amide bond was also observed upon Ser404 phosphorylation, with the effects further modulated by phosphorylation at other sites. Additional structural changes dependent on phosphorylation and/or tauR406W were observed and characterized by NMR. Conclusions: The phosphorylation-dependent proline isomerism Pin1 has been strongly implicated in tau aggregation and Alzheimer’s disease. These data suggest that tau phosphorylation is not directly increased by the R406W mutation. Instead, the data suggest induction of proline-405 cis amide bond formation and subsequent structural changes as a primary mechanism for the functional effects of the R406W mutation.
P4-454
ANTI-N-TERMINAL ABETA MAB 3A1 PREFERENTIALLY RECOGNIZES ABETA AGGREGATES AND DOES NOT CROSSREACT WITH APP
Jeffrey L. Frost1, James S. Foster2, Peggy Taylor1, Brian O’Nuallain1, 1 Biolegend Inc., Dedham, MA, USA; 2University of Tennessee Graduate School of Medicine, Knoxville, TN, USA. Contact e-mail: bonuallain@ biolegend.com Background: The murine anti-N-terminal Abeta monoclonal anti-
body (mAb) 3A1 was generated against dityrosine cross-linked Abeta1-40 protein species (CAPS). 3A1’s epitope comprises of Abeta’s first 15 amino acids, DAEFRHDSGYEVHHQ. The mAb has demonstrated activity in vivo by decreasing plaque burden
Poster Presentations: Wednesday, July 19, 2017
and increasing plasma Abeta in an APPswe/PS1DE9 transgenic mouse model of Alzheimer’s disease [Frost et al (2015) Neurobiol Aging. 36(12): 3187]. To better understand the mAb’s specificity for Abeta we established in vitro the antibody’s ability to recognize Abeta1-40 conformers (monomers, dimers, protofibrils), APP, and rodent Abeta. Methods: 3A1’s avidity for Abeta conformers, APP and rodent Abeta were determined using ELISA, and Western blot assays. Anti-N-terminal Abeta mAb, 6E10 [Kim et al. (1988) Neurosci. Res. Comm. 7:113], was used as positive control. Abeta conformers were generated as previously described [Welzel et al (2012) PLoS One. 7(11):e50317]. Results: MAb 3A1 had similar avidity for plate-immobilized Abeta1-40 conformers as mAb 6E10, with EC50 values in the sub nM range. Both antibodies had essentially no reactivity with rodent Abeta1-40. However, in contrast to 6E10, mAb 3A1 showed a strong preference for aggregated compared with monomeric Abeta1-40, and did not detect APP protein. Conclusions: The N-terminal Abeta reactive MAb 3A1 demonstrated novel specificity by preferentially targeting the aggregated peptide without cross-reacting with APP. This unique activity may be utilized in immunoassay(s) to advance current poor understanding on the role of Abeta species in Alzheimer’s disease.
P4-455
NEUROPROTECTIVE EFFECT OF CANNABINOID RECEPTORS IN NEUROINFLAMATION
Gemma Navarro Brugal1, Dasiel Borroto-Escuela2, Irene Reyes1, Edgar Angelats1, Jose Luis Labandeira3, Kjell Fuxe2, Rafael Franco1, 1University of Barcelona, Barcelona, Spain; 2Karolinska Institutet, Stockholm, Sweden; 3University of Santiago de Compostela, Santiago de Compostela, Spain. Contact e-mail: [email protected] Background: The hypothesis of direct interactions between pairs of
G-protein-coupled receptors relevant for CNS function, launched by Luigi Agnati and Kjell Fuxe, has been confirmed and is now widely accepted. Natural and synthetic cannabinoids target two types of G-protein-coupled receptors (GPCRs). Cannabinoid CB1 receptors, which are enriched in the CNS and cannabinoid CB2 receptors that are more abundant in peripheral tissues. Methods: Energy transfer techniques in HEK-293T cells to determine protein-protein interactions. Microglia primary cultures preparation. Different signaling methodology to detect cAMP, MAPK and Dinamyc Mass redistribution. Proximity Ligation Assay to detect protein-protein interaction in natural tissues. Results: Despite the moderate expression of CB2 receptors in brain, it has been demonstrated that CB1 and CB2 may for receptor heteromers (RHets) in the CNS. Therefore, natural or synthetic cannabinoids may act on CB1, CB2 and CB1 or CB2 containing heteromers. The research presented in this paper was undertaken to know whether these two receptors may be expressed in activated microglia. It is worth noting that current knowledge assumed that CB1 is more a neuronal than glial receptor whereas the opposite occurs for CB2. On the one hand, the expression of receptors and RHets is different in resting and activated microglia. Activation was assayed in the N9 cell line and in primary cultures of microglia using LPS and interferon gamma. On the other hand, the increase in CB1-CB2 RHets correlates with a potentiation of the effects of selective CB2 receptors. Our results show that the composition of cannabinoid receptors and RHets in resting microglia prevent microglia activation while
P1505
in conditions of microgliosis due to Parkinsonian conditions, cannabinoid agonist regulate microglial activation. Conclusions: The results indicate that pharmacological manipulation of cannabinoid receptors in conditions of neuroinflammation may have relevant benefits in conditions of neuroinflammation.
P4-456
TAU AND P53 IN ALZHEIMER’S DISEASE
Kathleen M. Farmer, Mariana Carretero-Murillo, Salome McAllen, Partha Sarkar, Rakez Kayed, University of Texas Medical Branch, Galveston, TX, USA. Contact e-mail: [email protected] Background: P53 acts as a master regulator of cell cycle control, apoptosis, and DNA repair. Tau has been proposed to play a role in DNA damage, which is one of the earliest pathological changes in Alzheimer’s disease (AD). As p53 becomes activated due to DNA damage, it may be possible that an interaction between tau and p53 occurs in the early stages of AD. In addition, tau oligomers have been found to develop toxic gain of function and are one of the major contributors to neuron death in AD. Tau oligomers may sequester and/or cause the aggregation of other proteins. Thus, we hypothesize that p53 may be sequestered by tau oligomers, inhibiting its function. Methods: We evaluated total p53, functional phospho-p53, and tau aggregation status in AD patients and Tg2576 mice using both commercial and novel antibodies with conformational epitopes common to oligomers of aggregated proteins. Results: We found that phospho-p53 levels are modulated in human AD brain in comparison to control brain. We also found that phospho-p53 colocalizes with tau oligomers in human AD brain, highlighting a potential overlap between DNA damage response and AD. Conclusions: Our findings suggest that tau oligomers may be interacting with p53 and causing a down regulation of functional p53 in AD. This may suggest that tau may be interacting in DNA damage response signaling and therefore affecting cell death. These results may have implications for a number of other neurodegenerative disorders. Therefore, further research is needed to understand the underlying signaling pathways of tau and p53 interaction.
P4-457
N-TRUNCATED AND PYROGLUTAMATEMODIFIED Ab ACCELERATES AGGREGATION OF a-SYNUCLEIN IN VITRO
Anja Schulze1, Janett K€oppen1, Michael Wermann1, Angelika H€ahnel2, Jessica Klehm2, Hans-Ulrich Demuth1, Stephan Schilling1 1 Fraunhofer Institute for Cell Therapy and Immunology, Halle, Germany; 2Fraunhofer IMWS, Halle, Germany. Contact e-mail: [email protected] Background: The aggregation and depositoion of misfolded a-synuclein and Ab represent hallmarks of Parkinson’s and Alzheimer’s disease, respectively. Interestingly, a-synuclein and Ab pathology are frequently observed in the same individual, leading to the hypothesis that both peptides mutually interact to facilitate neurodegeneration. Here, we studied the influence of Ab1-42 and pGluAb3-42 on the aggregation of a-synuclein in vitro. Methods: Human alpha-synuclein was recombinantly expressed in Escherichia coli and purified. Ab1-42 and pGlu- Ab3-42 were synthesized by solid phase synthesis. The aggregation of alpha-synuclein was investigated using Thioflavin-T fluorescence assay, atomic force (AFM)