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Vaccination Against Amyloidogenic Aggregates in Pancreatic Islets Prevents Development of Type 2 Diabetes Mellitus. Vaccines (Basel) 2020; 8:vaccines8010116. [PMID: 32131431 PMCID: PMC7157615 DOI: 10.3390/vaccines8010116] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/23/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a chronic progressive disease characterized by insulin resistance and insufficient insulin secretion to maintain normoglycemia. The majority of T2DM patients bear amyloid deposits mainly composed of islet amyloid polypeptide (IAPP) in their pancreatic islets. These-originally β-cell secretory products-extracellular aggregates are cytotoxic for insulin-producing β-cells and are associated with β-cell loss and inflammation in T2DM advanced stages. Due to the absence of T2DM preventive medicaments and the presence of only symptomatic drugs acting towards increasing hormone secretion and action, we aimed at establishing a novel disease-modifying therapy targeting the cytotoxic IAPP deposits in order to prevent the development of T2DM. We generated a vaccine based on virus-like particles (VLPs), devoid of genomic material, coupled to IAPP peptides inducing specific antibodies against aggregated, but not monomeric IAPP. Using a mouse model of islet amyloidosis, we demonstrate in vivo that our vaccine induced a potent antibody response against aggregated, but not soluble IAPP, strikingly preventing IAPP depositions, delaying onset of hyperglycemia and the induction of the associated pro-inflammatory cytokine Interleukin 1β (IL-1β). We offer the first cost-effective and safe disease-modifying approach targeting islet dysfunction in T2DM, preventing pathogenic aggregates without disturbing physiological IAPP function.
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Chen H, Sun D, Tian Y, Fan H, Liu Y, Morozova-Roche LA, Zhang C. Surface-Directed Structural Transition of Amyloidogenic Aggregates and the Resulting Neurotoxicity. ACS OMEGA 2020; 5:2856-2864. [PMID: 32095707 PMCID: PMC7034003 DOI: 10.1021/acsomega.9b03671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/27/2020] [Indexed: 06/10/2023]
Abstract
The transition of amyloidogenic species into ordered structures (i.e., prefibrillar oligomers, protofibrils, mature fibrils, and amyloidogenic aggregates) is closely associated with many neurodegenerative disease pathologies. It is increasingly appreciated that the liquid-solid interface contributes to peptide aggregation under physiological conditions. However, much remains to be explored on the molecular mechanism of surface-directed amyloid formation. We herein demonstrate that physical environmental conditions (i.e., negatively charged surface) affect amyloid formation. Nontoxic amyloid aggregates quickly develop into intertwisting fibrils on a negatively charged mica surface. These fibrillar structures show significant cytotoxicity on both neuroblastoma cell-lines (SH-SY5Y) and primary neural stem cells. Our results suggest an alternative amyloid development pathway, following which Aβ peptides form large amyloidogenic aggregates upon stimulation, and later transit into neurotoxic fibrillar structures while being trapped and aligned by a negatively charged surface. Conceivably, the interplay between chemical and physical environmental conditions plays important roles in the development of neurodegenerative diseases.
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Affiliation(s)
- Hao Chen
- School
of Chemical Engineering, Northwest University, Xi’an 710069, China
| | - Dan Sun
- State
Key Laboratory of Cultivation Base for Photoelectric Technology and
Functional Materials, Institute of Photonics and Photon-Technology, Northwest University, Xi’an 710069, China
| | - Yin Tian
- Laboratory
of Stem Cell and Tissue Engineering, Chongqing
Medical University, Chongqing 400016, China
| | - Haiming Fan
- College
of Chemistry and Materials Science, Northwest
University, Xi’an 710127, China
| | - Yonggang Liu
- Laboratory
of Stem Cell and Tissue Engineering, Chongqing
Medical University, Chongqing 400016, China
| | | | - Ce Zhang
- State
Key Laboratory of Cultivation Base for Photoelectric Technology and
Functional Materials, Institute of Photonics and Photon-Technology, Northwest University, Xi’an 710069, China
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Lam YPY, Wootton CA, Hands-Portman I, Wei J, Chiu CKC, Romero-Canelon I, Lermyte F, Barrow MP, O'Connor PB. Determination of the Aggregate Binding Site of Amyloid Protofibrils Using Electron Capture Dissociation Tandem Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:267-276. [PMID: 31922736 DOI: 10.1021/jasms.9b00053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Amyloid fibril formation is a hallmark in a range of human diseases. Analysis of the molecular details of amyloid aggregation, however, is limited by the difficulties in solubilizing, separating, and identifying the aggregated biomolecules. Additional labeling or protein modification is required in many current analytical techniques in order to provide molecular details of amyloid protein aggregation, but these modifications may result in protein structure disruption. Herein, ultrahigh resolution mass spectrometry (MS) with electron capture dissociation tandem MS (ECD MS/MS) has been applied to monitor the formation of early oligomers of human islet amyloid polypeptide (hIAPP), which aggregate rapidly in the pancreas of type II diabetes (T2D) patients. ECD MS/MS results show the aggregation region of the early oligomers is at the Ser-28/Ser-29 residue of a hIAPP unit and at the Asn-35 residue of another hIAPP unit near the C-terminus in the gas phase. These data contribute to the understanding of the binding site between hIAPP units which may help for specific target region therapeutic development in the future. Furthermore, MS has also been applied to quantify the amount of soluble amyloid protein remaining in the incubated solutions, which can be used to estimate the aggregation rate of amyloid protein during incubation (28 days). These data are further correlated with the results obtained using fluorescence spectroscopy and transmission electron microscopy (TEM) to generate a general overview of amyloid protein aggregation. The methods demonstrated in this article not only explore the aggregation site of hIAPP down to an amino acid residue level, but are also applicable to many amyloid protein aggregation studies.
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Affiliation(s)
- Yuko P Y Lam
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Christopher A Wootton
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Ian Hands-Portman
- Department of Life Sciences, Gibbet Hill Campus , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Juan Wei
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Cookson K C Chiu
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - I Romero-Canelon
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
- School of Pharmacy , University of Birmingham , Edgbaston , Birmingham B15 2TT , United Kingdom
| | - Frederik Lermyte
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Mark P Barrow
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Peter B O'Connor
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
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54
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Active-site environment of Cu bound amyloid β and amylin peptides. J Biol Inorg Chem 2019; 24:1245-1259. [DOI: 10.1007/s00775-019-01724-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/05/2019] [Indexed: 01/09/2023]
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55
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Srinivasan E, Ravikumar S, Venkataramanan S, Purohit R, Rajasekaran R. Molecular mechanics and quantum chemical calculations unveil the combating effect of baicalein on human islet amyloid polypeptide aggregates. MOLECULAR SIMULATION 2019. [DOI: 10.1080/08927022.2019.1660778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- E. Srinivasan
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, India
| | - S. Ravikumar
- Multidisciplinary Center for Biomedical Research, Aarupadai Veedu Medical College and Hospital, Vinayaka Missions Research Foundation, Puducherry, India
| | - S. Venkataramanan
- Department of Diagnostic and Allied Health Science, Faculty of Health and Life Sciences, Management and Science University, Shah Alam, Malaysia
| | - Rituraj Purohit
- Structural Bioinformatics Laboratory, Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, India
| | - R. Rajasekaran
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, India
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56
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Alves NA, Dias LG, Frigori RB. Synergistic long-range effects of mutations underlie aggregation propensities of amylin analogues. J Mol Model 2019; 25:263. [PMID: 31428870 DOI: 10.1007/s00894-019-4137-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 07/14/2019] [Indexed: 12/16/2022]
Abstract
The USFDA has approved pramlintide, commercially named Symlin (sIAPP), as adjunctive therapy for type 2 diabetes (T2D). This analogue of the human amylin peptide (hIAPP) has triple proline substitutions typical of the rat isoform (rIAPP). Recently, it was proposed that pramlintide solubility and aggregation resistance might be improved by incorporating further mutations, as S20R, screened from the wild-type porcine isoform (pIAPP), which leads to the variant named sIAPP+. To better elucidate how such properties might be systematically induced in rationally designed analogues, we performed comparative assessments of rIAPP, sIAPP, and sIAPP+ using replica-exchange molecular dynamics (REMD) with an accurate combination of force field Charmm22* and explicit aqueous solvation TIP4P/Ew. Our thermo-structural analyses show that sIAPP exhibits a thermal conversion channel of helices[Formula: see text]-sheets resembling hIAPP. This channel is depleted in rIAPP and is absent in sIAPP+. As a consequence, sIAPP+ presents an overall decrease of β-like secondary structures and an overstabilization of α-helices. Additionally, we observed in rIAPP and sIAPP+ an increase in the backbone RMSF of molecular terminals and the exposed area of key residues. These structural features of sIAPP+ suggest a nonamyloidogenic character, which is corroborated by our judicious estimate of the electrostatic component of the solvation free energy using a generalized Born model, and so it may constitute an alternative strategy to sIAPP as a peptide analogue of hIAPP. Furthermore, our findings confirm that different aggregation propensities of amylin and its analogues are synergistically modulated by long-range effects of key mutations. Graphical Abstract S20R-Pramlintide.
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Affiliation(s)
- Nelson A Alves
- Departamento de Física, FFCLRP, Universidade de São Paulo, Avenida Bandeirantes, 3900, Ribeirão Preto, 14040-901, SP, Brazil.
| | - Luis G Dias
- Departamento de Química, FFCLRP, Universidade de São Paulo, Avenida Bandeirantes, 3900, Ribeirão Preto, 14040-901, SP, Brazil
| | - Rafael B Frigori
- Universidade Tecnológica Federal do Paraná, Rua Cristo Rei 19, Toledo, 85902-490, PR, Brazil
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57
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Zhu X, Wen Y, Zhao Y, Liu Y, Sun J, Liu J, Liu J, Chen L. Functionalized chitosan-modified defect-related luminescent mesoporous silica nanoparticles as new inhibitors for hIAPP aggregation. NANOTECHNOLOGY 2019; 30:315705. [PMID: 30917341 DOI: 10.1088/1361-6528/ab13ef] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Human islet amyloid polypeptide (hIAPP or amylin) forms the amyloid deposits that is an important factor in the induction of type II diabetes. Accordingly, it is essential to efficiently and accurately inhibit the aggregation of hIAPP for the treatment and prevention of the disease. Here, defect mesoporous silica (DLMSN), with blue fluorescence, can perfectly achieve the accurate positioning in cells or organisms. DL@CS@NF cannot only specifically bind to a hIAPP monomer, but also effectively inhibit hIAPP aggregation, reduce cytotoxicity and overcome the instability and inefficiency of NF(N-Me)GA(N-Me)IL (NF). Furthermore, DL@CS@NF nanoparticles can significantly improve the survival rate of islet cells, stabilize the mitochondrial membrane potential, reduce the content of intracellular reactive oxygen species. In summary, DL@CS@NF nanoparticles may have broader implications in inhibiting the aggregation of hIAPP and reducing cytotoxicity.
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Affiliation(s)
- Xufeng Zhu
- Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, People's Republic of China
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58
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Specific keratinase derived designer peptides potently inhibit Aβ aggregation resulting in reduced neuronal toxicity and apoptosis. Biochem J 2019; 476:1817-1841. [DOI: 10.1042/bcj20190183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 11/17/2022]
Abstract
Abstract
Compelling evidence implicates self-assembly of amyloid-β (Aβ1–42) peptides into soluble oligomers and fibrils as a major underlying event in Alzheimer's disease (AD) pathogenesis. Herein, we employed amyloid-degrading keratinase (kerA) enzyme as a key Aβ1–42-binding scaffold to identify five keratinase-guided peptides (KgPs) capable of interacting with and altering amyloidogenic conversion of Aβ1–42. The KgPs showed micromolar affinities with Aβ1–42 and abolished its sigmoidal amyloidogenic transition, resulting in abrogation of fibrillogenesis. Comprehensive assessment using dynamic light scattering (DLS), atomic force microscopy (AFM) and Fourier-transform infrared (FTIR) spectroscopy showed that KgPs induced the formation of off-pathway oligomers comparatively larger than the native Aβ1–42 oligomers but with a significantly reduced cross-β signature. These off-pathway oligomers exhibited low immunoreactivity against oligomer-specific (A11) and fibril-specific (OC) antibodies and rescued neuronal cells from Aβ1–42 oligomer toxicity as well as neuronal apoptosis. Structural analysis using molecular docking and molecular dynamics (MD) simulations showed two preferred KgP binding sites (Lys16–Phe20 and Leu28–Val39) on the NMR ensembles of monomeric and fibrillar Aβ1–42, indicating an interruption of crucial hydrophobic and aromatic interactions. Overall, our results demonstrate a new approach for designing potential anti-amyloid molecules that could pave way for developing effective therapeutics against AD and other amyloid diseases.
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59
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Es-haghi A, Jahedi Moghaddam M, Shahpasand K. Role of Pre-molten Globule Structure in Protein Amyloid Fibril Formation. AVICENNA JOURNAL OF MEDICAL BIOCHEMISTRY 2019. [DOI: 10.34172/ajmb.2019.07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The conversion of a protein from its native conformation to the pathogenic form is a critical event in the pathogenesis of several neurodegenerative disorders such as Alzheimer’s (AD), Parkinson’s, and Huntington’s diseases, along with type II diabetic mellitus. Although there are several reports on the mechanism of protein aggregation, the actual conformation playing a part in the pathogenicity is yet unclear. Accordingly, the present study summarizes the early pathogenic conformation resulting in several protein aggregations. It is well-documented that a pre-molten globule (MG) structure appears at the early stages of some proteins. Pre-MG is one of the intermediate structures, which is formed during some protein unfolding processes. In addition, it is shown that the pre-molten structure is more flexible than the mature MG one and thus, protein easily rearranges to form amyloid fibrils in this conformation. Therefore, protein aggregation is halted by preventing the pre-MG structure. The strategy of protein aggregation prevention has profound implications in fighting the devastating disorder.
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Affiliation(s)
- Ali Es-haghi
- Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran
| | | | - Koorosh Shahpasand
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Centre of Education, Culture and Research, Tehran, Iran
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60
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Heller A, Coffman SS, Friedman KA. Obesity-Dependent Accumulation of Titanium in the Pancreas of Type 2 Diabetic Donors. Chem Res Toxicol 2019; 32:1351-1356. [DOI: 10.1021/acs.chemrestox.8b00304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Adam Heller
- John J. McKetta Department of Chemical Engineering, University of Texas, Austin, Texas 78712, United States
| | - Sheryl S. Coffman
- John J. McKetta Department of Chemical Engineering, University of Texas, Austin, Texas 78712, United States
| | - Keith A. Friedman
- John J. McKetta Department of Chemical Engineering, University of Texas, Austin, Texas 78712, United States
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61
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Alshathly MR. Efficacy of Ginger ( Zingiber officinale) in Ameliorating Streptozotocin-Induced Diabetic Liver Injury in Rats: Histological and Biochemical Studies. J Microsc Ultrastruct 2019; 7:91-101. [PMID: 31293891 PMCID: PMC6585475 DOI: 10.4103/jmau.jmau_16_19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Ginger (Zingiber officinale) was reported to have an antioxidant, antidiabetic effect. This study was done to investigate its therapeutic effect against functional and structural alteration in liver of diabetic rat (intraperitoneal streptozotocin (STZ) in a dose of 60 mg/kg/bw). Thirty adult male rats (three-months-old and 250 g weight) were sorted into five groups (N=6). G1 used as control, G2 was diabetic rats without any treatment, G3 was diabetic rats given oral ginger in a dose of 500 mg/kg/bw, G4 was diabetic rats treated with metformin (500 mg/kg/bw) while G5 received ginger orally. The experiment lasts for six weeks, animals were anesthetized by ether, body weight was recorded for all animals. Blood was collected for further analysis of lipid profile, liver enzymes and total antioxidant. Liver was dissected, weighted and samples were processed for histopathological study. The results showed significant decrease of glaucous level and liver enzymes in ginger treated rats. Total antioxidant was preserved. Ginger lowered blood glucose, level, regained body weight and liver index to near normal values. Diabetes induced degenerative changes and micro-vesicular lipid deposition in hepatocytes with moderate portal area fibrosis. Ultrastructure study confirmed such changes beside demonstrating increased lipid deposition in fat storing cells. Ginger was found to ameliorate those changes in treated animals. Results were matching metformin effects. In conclusion, Ginger as a natural safe Herbal medication can be used to support liver functions in diabetic status.
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Affiliation(s)
- Mona R. Alshathly
- Department of Biological Sciences, Faculty of Science, Northern Border University, Arar, Saudi Arabia
- Department of Biology, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
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62
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Azadirachtin inhibits amyloid formation, disaggregates pre-formed fibrils and protects pancreatic β-cells from human islet amyloid polypeptide/amylin-induced cytotoxicity. Biochem J 2019; 476:889-907. [DOI: 10.1042/bcj20180820] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/18/2019] [Accepted: 02/27/2019] [Indexed: 12/16/2022]
Abstract
Abstract
The human islet amyloid polypeptide (hIAPP) or amylin is the major constituent of amyloidogenic aggregates found in pancreatic islets of type 2 diabetic patients that have been associated with β-cell dysfunction and/or death associated with type 2 diabetes mellitus (T2DM). Therefore, developing and/or identifying inhibitors of hIAPP aggregation pathway and/or compound that can mediate disaggregation of preformed aggregates holds promise as a medical intervention for T2DM management. In the current study, the anti-amyloidogenic potential of Azadirachtin (AZD)—a secondary metabolite isolated from traditional medicinal plant Neem (Azadirachta indica)—was investigated by using a combination of biophysical and cellular assays. Our results indicate that AZD supplementation not only inhibits hIAPP aggregation but also disaggregates pre-existing hIAPP fibrils by forming amorphous aggregates that are non-toxic to pancreatic β-cells. Furthermore, AZD supplementation in pancreatic β-cells (INS-1E) resulted in inhibition of oxidative stress; along with restoration of the DNA damage, lipid peroxidation and the associated membrane damage, endoplasmic reticulum stress and mitochondrial membrane potential. AZD treatment also restored glucose-stimulated insulin secretion from pancreatic islets exposed to hIAPP. All-atom molecular dynamics simulation studies on full-length hIAPP pentamer with AZD suggested that AZD interacted with four possible binding sites in the amyloidogenic region of hIAPP. In summary, our results suggest AZD to be a promising candidate for combating T2DM and related amyloidogenic disorders.
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63
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Large-scale all-atom molecular dynamics alanine-scanning of IAPP octapeptides provides insights into the molecular determinants of amyloidogenicity. Sci Rep 2019; 9:2530. [PMID: 30792475 PMCID: PMC6384915 DOI: 10.1038/s41598-018-38401-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 12/11/2018] [Indexed: 12/11/2022] Open
Abstract
In order to investigate the early phase of the amyloid formation by the short amyloidogenic octapeptide sequence (‘NFGAILSS’) derived from IAPP, we carried out a 100ns all-atom molecular dynamics (MD) simulations of systems that contain 27 peptides and over 30,000 water molecules. The large-scale calculations were performed for the wild type sequence and seven alanine-scanned sequences using AMBER 8.0 on RIKEN’s special purpose MD-GRAPE3 supercomputer, using the all-atom point charge force field ff99, which do not favor β-structures. Large peptide clusters (size 18–26 mers) were observed for all simulations, and our calculations indicated that isoleucine at position 5 played important role in the formation of β-rich clusters. In the oligomeric state, the wild type and the S7A sequences had the highest β-structure content (~14%), as calculated by DSSP, in line with experimental observations, whereas I5A and G3A had the highest helical content (~20%). Importantly, the β-structure preferences of wild type IAPP originate from its association into clusters and are not intrinsic to its sequence. Altogether, the results of this first large-scale, multi-peptide all-atom molecular dynamics simulation appear to provide insights into the mechanism of amyloidogenic and non-amyloidogenic oligomers that mainly corroborate previous experimental observations.
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64
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Todorova N, Yarovsky I. The Enigma of Amyloid Forming Proteins: Insights From Molecular Simulations. Aust J Chem 2019. [DOI: 10.1071/ch19059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Molecular level insight into the interplay between protein sequence, structure, and conformational dynamics is crucial for the comprehensive understanding of protein folding, misfolding, and aggregation phenomena that are pertinent to the formation of amyloid fibrils implicated in several degenerative diseases. Computational modelling provides insight into protein behaviour at spatial and temporal resolution still largely outside the reach of experiments. Herein we present an account of our theoretical modelling research conducted in collaboration with several experimental groups where we explored the effects of local environment on the structure and aggregation propensity of several types of amyloidogenic peptides and proteins, including apolipoprotein C-II, insulin, amylin, and amyloid-β using a variety of computational approaches.
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Sub-Toxic Human Amylin Fragment Concentrations Promote the Survival and Proliferation of SH-SY5Y Cells via the Release of VEGF and HspB5 from Endothelial RBE4 Cells. Int J Mol Sci 2018; 19:ijms19113659. [PMID: 30463298 PMCID: PMC6274958 DOI: 10.3390/ijms19113659] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 12/19/2022] Open
Abstract
Human amylin is a 37-residue peptide hormone (hA1-37) secreted by β-cells of the pancreas and, along with insulin, is directly associated with type 2 diabetes mellitus (T2DM). Amyloid deposits within the islets of the pancreas represent a hallmark of T2DM. Additionally, amylin aggregates have been found in blood vessels and/or brain of patients with Alzheimer’s disease, alone or co-deposited with β-amyloid. The purpose of this study was to investigate the neuroprotective potential of human amylin in the context of endothelial-neuronal “cross-talk”. We initially performed dose-response experiments to examine cellular toxicity (quantified by the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] MTT assay) of different hA17–29 concentrations in endothelial cells (RBE4). In the culture medium of these cells, we also measured heat shock protein B5 (HspB5) levels by ELISA, finding that even a sub-toxic concentration of hA17–29 (3 µM) produced an increase of HspB5. Using a cell medium of untreated and RBE4 challenged for 48 h with a sub-toxic concentration of hA17–29, we determined the potential beneficial effect of their addition to the medium of neuroblastoma SH-SY5Y cells. These cells were subsequently incubated for 48 h with a toxic concentration of hA17–29 (20 µM). We found a complete inhibition of hA17–29 toxicity, potentially related to the presence in the conditioned medium not only of HspB5, but also of vascular endothelial growth factor (VEGF). Pre-treating SH-SY5Y cells with the anti-Flk1 antibody, blocking the VEGF receptor 2 (VEGFR2), significantly decreased the protective effects of the conditioned RBE4 medium. These data, obtained by indirectly measuring VEGF activity, were strongly corroborated by the direct measurement of VEGF levels in conditioned RBE4 media as detected by ELISA. Altogether, these findings highlighted a novel role of sub-toxic concentrations of human amylin in promoting the secretion of proteic factors by endothelial cells (HspB5 and VEGF) that support the survival and proliferation of neuron-like cells.
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66
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Alves NA, Frigori RB. In Silico Comparative Study of Human and Porcine Amylin. J Phys Chem B 2018; 122:10714-10721. [DOI: 10.1021/acs.jpcb.8b09363] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nelson A. Alves
- Departamento de Fı́sica, FFCLRP, Universidade de São Paulo, Avenida Bandeirantes, 3900. Ribeirão Preto 14040-901, SP Brazil
| | - Rafael B. Frigori
- Universidade Tecnológica Federal do Paraná, Rua Cristo Rei 19, Toledo 85902-490, PR Brazil
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67
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Atrián-Blasco E, Gonzalez P, Santoro A, Alies B, Faller P, Hureau C. Cu and Zn coordination to amyloid peptides: From fascinating chemistry to debated pathological relevance. Coord Chem Rev 2018; 375:38-55. [PMID: 30262932 DOI: 10.1016/j.ccr.2018.04.007] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Several diseases share misfolding of different peptides and proteins as a key feature for their development. This is the case of important neurodegenerative diseases such as Alzheimer's and Parkinson's diseases and type II diabetes mellitus. Even more, metal ions such as copper and zinc might play an important role upon interaction with amyloidogenic peptides and proteins, which could impact their aggregation and toxicity abilities. In this review, the different coordination modes proposed for copper and zinc with amyloid-β, α-synuclein and IAPP will be reviewed as well as their impact on the aggregation, and ROS production in the case of copper. In addition, a special focus will be given to the mutations that affect metal binding and lead to familial cases of the diseases. Different modifications of the peptides that have been observed in vivo and could be relevant for the coordination of metal ions are also described.
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Affiliation(s)
- Elena Atrián-Blasco
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT, 31077 Toulouse Cedex 4, France
| | - Paulina Gonzalez
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Alice Santoro
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Bruno Alies
- Université de Bordeaux, ChemBioPharm INSERM U1212 CNRS UMR 5320, Bordeaux, France
| | - Peter Faller
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Christelle Hureau
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT, 31077 Toulouse Cedex 4, France
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68
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Analysis of multiply charged monomers and dimers of human islet amyloid polypeptide by collision-induced dissociation with electrospray ionization mass spectrometry. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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69
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IAPP in type II diabetes: Basic research on structure, molecular interactions, and disease mechanisms suggests potential intervention strategies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018. [DOI: 10.1016/j.bbamem.2018.02.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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70
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Sahoo BR, Genjo T, Cox SJ, Stoddard AK, Anantharamaiah GM, Fierke C, Ramamoorthy A. Nanodisc-Forming Scaffold Protein Promoted Retardation of Amyloid-Beta Aggregation. J Mol Biol 2018; 430:4230-4244. [PMID: 30170005 DOI: 10.1016/j.jmb.2018.08.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/23/2018] [Accepted: 08/16/2018] [Indexed: 10/28/2022]
Abstract
Peptidic nanodiscs are useful membrane mimetic tools for structural and functional studies of membrane proteins, and membrane interacting peptides including amyloids. Here, we demonstrate anti-amyloidogenic activities of a nanodisc-forming 18-residue peptide (denoted as 4F), both in lipid-bound and lipid-free states by using Alzheimer's amyloid-beta (Aβ40) peptide as an example. Fluorescence-based amyloid fibrillation kinetic assays showed a significant delay in Aβ40 amyloid aggregation by the 4F peptide. In addition, 4F-encased lipid nanodiscs, at an optimal concentration of 4F (>20 μM) and nanodisc size (<10 nm), significantly affect amyloid fibrillation. A comparison of experimental results obtained from nanodiscs with that obtained from liposomes revealed a substantial inhibitory efficacy of 4F-lipid nanodiscs against Aβ40 aggregation and were also found to be suitable to trap Aβ40 intermediates. A combination of atomistic molecular dynamics simulations with NMR and circular dichroism experimental results exhibited a substantial change in Aβ40 conformation upon 4F binding through electrostatic and π-π interactions. Specifically, the 4F peptide was found to interfere with the central β-sheet-forming residues of Aβ40 through substantial hydrogen, π-π, and π-alkyl interactions. Fluorescence experiments and coarse-grained molecular dynamics simulations showed the formation of a ternary complex, where Aβ40 binds to the proximity of peptidic belt and membrane surface that deaccelerate amyloid fibrillation. Electron microscopy images revealed short and thick amyloid fibers of Aβ40 formed in the presence of 4F or 4F-lipid nanodsics. These findings could aid in the development of amyloid inhibitors as well as in stabilizing Aβ40 intermediates for high-resolution structural and neurobiological studies.
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Affiliation(s)
- Bikash Ranjan Sahoo
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Biophysics Program, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Takuya Genjo
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Biophysics Program, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Sarah J Cox
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Andrea K Stoddard
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | | | - Carol Fierke
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Department of Chemistry, University of Texas A&M, College Station, TX 77843-3255, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Biophysics Program, University of Michigan, Ann Arbor, MI 48109-1055, USA.
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71
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Abedini A, Derk J, Schmidt AM. The receptor for advanced glycation endproducts is a mediator of toxicity by IAPP and other proteotoxic aggregates: Establishing and exploiting common ground for novel amyloidosis therapies. Protein Sci 2018; 27:1166-1180. [PMID: 29664151 PMCID: PMC6032365 DOI: 10.1002/pro.3425] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 12/23/2022]
Abstract
Proteotoxicity plays a key role in many devastating human disorders, including Alzheimer's, Huntington's and Parkinson's diseases; type 2 diabetes; systemic amyloidosis; and cardiac dysfunction, to name a few. The cellular mechanisms of proteotoxicity in these disorders have been the focus of considerable research, but their role in prevalent and morbid disorders, such as diabetes, is less appreciated. There is a large body of literature on the impact of glucotoxicity and lipotoxicity on insulin-producing pancreatic β-cells, and there is increasing recognition that proteotoxicty plays a key role. Pancreatic islet amyloidosis by the hormone IAPP, the production of advanced glycation endproducts (AGE), and insulin misprocessing into cytotoxic aggregates are all sources of β-cell proteotoxicity in diabetes. AGE, produced by the reaction of reducing sugars with proteins and lipids are ligands for the receptor for AGE (RAGE), as are the toxic pre-fibrillar aggregates of IAPP produced during amyloid formation. The mechanisms of amyloid formation by IAPP in vivo or in vitro are not well understood, and the cellular mechanisms of IAPP-induced β-cell death are not fully defined. Here, we review recent findings that illuminate the factors and mechanisms involved in β-cell proteotoxicity in diabetes. Together, these new insights have far-reaching implications for the establishment of unifying mechanisms by which pathological amyloidoses imbue their injurious effects in vivo.
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Affiliation(s)
- Andisheh Abedini
- Diabetes Research Program, Division of Endocrinology, Department of MedicineNew York University Medical Center, 550 First Avenue, Smilow 906New YorkNew York10016
| | - Julia Derk
- Diabetes Research Program, Division of Endocrinology, Department of MedicineNew York University Medical Center, 550 First Avenue, Smilow 906New YorkNew York10016
| | - Ann Marie Schmidt
- Diabetes Research Program, Division of Endocrinology, Department of MedicineNew York University Medical Center, 550 First Avenue, Smilow 906New YorkNew York10016
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72
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Pradhan N, Debnath K, Mandal S, Jana NR, Jana NR. Antiamyloidogenic Chemical/Biochemical-Based Designed Nanoparticle as Artificial Chaperone for Efficient Inhibition of Protein Aggregation. Biomacromolecules 2018; 19:1721-1731. [DOI: 10.1021/acs.biomac.8b00671] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Nibedita Pradhan
- Centre for Advanced Materials, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Koushik Debnath
- Centre for Advanced Materials, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Suman Mandal
- Centre for Advanced Materials, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Nihar R. Jana
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon 122051, India
| | - Nikhil R. Jana
- Centre for Advanced Materials, Indian Association for the Cultivation of Science, Kolkata 700032, India
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73
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Rawat A, Langen R, Varkey J. Membranes as modulators of amyloid protein misfolding and target of toxicity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1863-1875. [PMID: 29702073 DOI: 10.1016/j.bbamem.2018.04.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/19/2018] [Accepted: 04/19/2018] [Indexed: 12/15/2022]
Abstract
Abnormal protein aggregation is a hallmark of various human diseases. α-Synuclein, a protein implicated in Parkinson's disease, is found in aggregated form within Lewy bodies that are characteristically observed in the brains of PD patients. Similarly, deposits of aggregated human islet amyloid polypeptide (IAPP) are found in the pancreatic islets in individuals with type 2 diabetes mellitus. Significant number of studies have focused on how monomeric, disaggregated proteins transition into various amyloid structures leading to identification of a vast number of aggregation promoting molecules and processes over the years. Inasmuch as these factors likely enhance the formation of toxic, misfolded species, they might act as risk factors in disease. Cellular membranes, and particularly certain lipids, are considered to be among the major players for aggregation of α-synuclein and IAPP, and membranes might also be the target of toxicity. Past studies have utilized an array of biophysical tools, both in vitro and in vivo, to expound the membrane-mediated aggregation. Here, we focus on membrane interaction of α-synuclein and IAPP, and how various kinds of membranes catalyze or modulate the aggregation of these proteins and how, in turn, these proteins disrupt membrane integrity, both in vitro and in vivo. The membrane interaction and subsequent aggregation has been briefly contrasted to aggregation of α-synuclein and IAPP in solution. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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Affiliation(s)
- Anoop Rawat
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, United States
| | - Ralf Langen
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, United States.
| | - Jobin Varkey
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, United States.
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74
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Sasahara K. Membrane-mediated amyloid deposition of human islet amyloid polypeptide. Biophys Rev 2018; 10:453-462. [PMID: 29204886 PMCID: PMC5899711 DOI: 10.1007/s12551-017-0351-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/14/2017] [Indexed: 01/01/2023] Open
Abstract
Amyloid deposition of human islet amyloid polypeptide (hIAPP) within the islet of Langerhans is closely associated with type II diabetes mellitus. Accumulating evidence indicates that the membrane-mediated aggregation and subsequent deposition of hIAPP are linked to the dysfunction and death of insulin-producing pancreatic β-cells, but the molecular process of hIAPP deposition is poorly understood. In this review, I focus on recent in vitro studies utilizing model membranes to observe the membrane-mediated aggregation/deposition of hIAPP. Membrane surfaces can serve as templates for both hIAPP adsorption and aggregation. Using high-sensitivity surface analyzing/imaging techniques that can characterize the processes of hIAPP aggregation and deposition at the membrane surface, these studies provide valuable insights into the mechanism of membrane damage caused by amyloid deposition of the peptide.
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Affiliation(s)
- Kenji Sasahara
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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75
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Press M, Jung T, König J, Grune T, Höhn A. Protein aggregates and proteostasis in aging: Amylin and β-cell function. Mech Ageing Dev 2018; 177:46-54. [PMID: 29580826 DOI: 10.1016/j.mad.2018.03.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 03/22/2018] [Indexed: 01/07/2023]
Abstract
The ubiquitin-proteasomal-system (UPS) and the autophagy-lysosomal-system (ALS) are both highly susceptible for disturbances leading to the accumulation of cellular damage. A decline of protein degradation during aging results in the formation of oxidatively damaged and aggregated proteins finally resulting in failure of cellular functionality. Besides protein aggregation in response to oxidative damage, amyloids are a different type of protein aggregates able to distract proteostasis and interfere with cellular functionality. Amyloids are clearly linked to the pathogenesis of age-related degenerative diseases such as Alzheimer's disease. Human amylin is one of the peptides forming fibrils in β-sheet conformation finally leading to amyloid formation. In contrast to rodent amylin, human amylin is prone to form amyloidogenic aggregates, proposed to play a role in the pathogenesis of Type 2 Diabetes by impairing β-cell functionality. Since aggregates such as lipofuscin and β-amyloid are known to impair proteostasis, it is likely to assume similar effects for human amylin. In this review, we focus on the effects of IAPP on UPS and ALS and their role in amylin degradation, since both systems play a crucial role in maintaining proteome balance thereby influencing, at least in part, cellular fate and aging.
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Affiliation(s)
- Michaela Press
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany; German Center for Diabetes Research (DZD), 85764 Muenchen-Neuherberg, Germany.
| | - Tobias Jung
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany; German Center for Cardiovascular Research (DZHK), 10117 Berlin, Germany.
| | - Jeannette König
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany.
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany; German Center for Diabetes Research (DZD), 85764 Muenchen-Neuherberg, Germany; German Center for Cardiovascular Research (DZHK), 10117 Berlin, Germany; NutriAct - Competence Cluster Nutrition Research Berlin-Potsdam, 14558 Nuthetal, Germany; Institute of Nutrition, University of Potsdam, 14558 Nuthetal, Germany.
| | - Annika Höhn
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558 Nuthetal, Germany; German Center for Diabetes Research (DZD), 85764 Muenchen-Neuherberg, Germany.
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76
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Abstract
The oligomerization and fibrillation of human islet amyloid polypeptide (hIAPP) play a central role in the pathogenesis of type 2 diabetes. Strategies for remodelling the formation of hIAPP oligomers and fibrils have promising application potential in type 2 diabetes therapy. Herein, we demonstrated that PEG-PE micelle could inhibit hIAPP oligomerization and fibrillation through blocking the hydrophobic interaction and the conformational change from random coil to β-sheet structures of hIAPP. In addition, we also found that PEG-PE micelle could remodel the preformed hIAPP fibrils allowing the formation of short fibrils and co-aggregates. Taken together, PEG-PE micelle could rescue hIAPP-induced cytotoxicity by decreasing the content of hIAPP oligomers and fibrils that are related to the oxidative stress and cell membrane permeability. This study could be beneficial for the design and development of antiamyloidogenic agents.
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77
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Salamatova E, Cunha AV, Bloem R, Roeters SJ, Woutersen S, Jansen TLC, Pshenichnikov MS. Hydrophobic Collapse in N-Methylacetamide-Water Mixtures. J Phys Chem A 2018; 122:2468-2478. [PMID: 29425450 PMCID: PMC6028151 DOI: 10.1021/acs.jpca.8b00276] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/02/2018] [Indexed: 11/28/2022]
Abstract
Aqueous N-methylacetamide solutions were investigated by polarization-resolved pump-probe and 2D infrared spectroscopy (2D IR), using the amide I mode as a reporter. The 2D IR results are compared with molecular dynamics simulations and spectral calculations to gain insight into the molecular structures in the mixture. N-Methylacetamide and water molecules tend to form clusters with "frozen" amide I dynamics. This is driven by a hydrophobic collapse as the methyl groups of the N-methylacetamide molecules cluster in the presence of water. Since the studied system can be considered as a simplified model for the backbone of proteins, the present study forms a convenient basis for understanding the structural and vibrational dynamics in proteins. It is particularly interesting to find out that a hydrophobic collapse as the one driving protein folding is observed in such a simple system.
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Affiliation(s)
- Evgeniia Salamatova
- Zernike
Institute for Advanced Materials, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ana V. Cunha
- Zernike
Institute for Advanced Materials, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Robbert Bloem
- Van
’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Steven J. Roeters
- Van
’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Sander Woutersen
- Van
’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Thomas L. C. Jansen
- Zernike
Institute for Advanced Materials, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Maxim S. Pshenichnikov
- Zernike
Institute for Advanced Materials, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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78
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Tsiolaki PL, Nasi GI, Baltoumas FA, Louros NN, Magafa V, Hamodrakas SJ, Iconomidou VA. αCGRP, another amyloidogenic member of the CGRP family. J Struct Biol 2018; 203:27-36. [PMID: 29501724 DOI: 10.1016/j.jsb.2018.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/26/2018] [Accepted: 02/28/2018] [Indexed: 10/17/2022]
Abstract
The Calcitonin-gene related peptide (CGRP) family is a group of peptide hormones, which consists of IAPP, calcitonin, adrenomedullin, intermedin, αCGRP and βCGRP. IAPP and calcitonin have been extensively associated with the formation of amyloid fibrils, causing Type 2 Diabetes and Medullary Thyroid Carcinoma, respectively. In contrast, the potential amyloidogenic properties of αCGRP still remain unexplored, although experimental trials have indicated its presence in deposits, associated with the aforementioned disorders. Therefore, in this work, we investigated the amyloidogenic profile of αCGRP, a 37-residue-long peptide hormone, utilizing both biophysical experimental techniques and Molecular Dynamics simulations. These efforts unravel a novel amyloidogenic member of the CGRP family and provide insights into the mechanism underlying the αCGRP polymerization.
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Affiliation(s)
- Paraskevi L Tsiolaki
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 157 01, Greece.
| | - Georgia I Nasi
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 157 01, Greece.
| | - Fotis A Baltoumas
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 157 01, Greece.
| | - Nikolaos N Louros
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 157 01, Greece.
| | - Vassiliki Magafa
- Department of Pharmacy, University of Patras, Patras 26504, Greece.
| | - Stavros J Hamodrakas
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 157 01, Greece.
| | - Vassiliki A Iconomidou
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 157 01, Greece.
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79
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Amyloid growth and membrane damage: Current themes and emerging perspectives from theory and experiments on Aβ and hIAPP. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1625-1638. [PMID: 29501606 DOI: 10.1016/j.bbamem.2018.02.022] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 12/15/2022]
Abstract
Alzheimer's Disease (AD) and Type 2 diabetes mellitus (T2DM) are two incurable diseases both hallmarked by an abnormal deposition of the amyloidogenic peptides Aβ and Islet Amyloid Polypeptide (IAPP) in affected tissues. Epidemiological data demonstrate that patients suffering from diabetes are at high risk of developing AD, thus making the search for factors common to the two pathologies of special interest for the design of new therapies. Accumulating evidence suggests that the toxic properties of both Aβ or IAPP are ascribable to their ability to damage the cell membrane. However, the molecular details describing Aβ or IAPP interaction with membranes are poorly understood. This review focuses on biophysical and in silico studies addressing these topics. Effects of calcium, cholesterol and membrane lipid composition in driving aberrant Aβ or IAPP interaction with the membrane will be specifically considered. The cross correlation of all these factors appears to be a key issue not only to shed light in the countless and often controversial reports relative to this area but also to gain valuable insights into the central events leading to membrane damage caused by amyloidogenic peptides. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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80
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Staniszewska-Slezak E, Wiercigroch E, Fedorowicz A, Buczek E, Mateuszuk L, Baranska M, Chlopicki S, Malek K. A possible Fourier transform infrared-based plasma fingerprint of angiotensin-converting enzyme inhibitor-induced reversal of endothelial dysfunction in diabetic mice. JOURNAL OF BIOPHOTONICS 2018; 11:e201700044. [PMID: 28700133 DOI: 10.1002/jbio.201700044] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/10/2017] [Accepted: 06/06/2017] [Indexed: 06/07/2023]
Abstract
Angiotensin-converting enzyme inhibitors (ACE-I) display vasoprotective activity and represent the cornerstone in the treatment of cardiovascular diseases. In this study, we tested whether Fourier transform infrared (FTIR)-based analysis of blood plasma is sensitive to detect vasoprotective effects of treatment with perindopril including reversal of endothelial dysfunction in diabetes. For this purpose, plasma samples were collected from untreated db/db mice, db/db mice treated with 2 or 10 mg/kg perindopril and db+ mice. The effect of perindopril on endothelial function was examined in ex vivo aortic rings; 10 mg/kg but not 2 mg/kg of perindopril reversed endothelial dysfunction. In plasma of db/db mice, the balance between conformations of plasma proteins was noted, and treatment with perindopril at a high dose but not at a low dose reversed this effect. This was revealed by amide II/amide I ratio attributed to increased β-sheet formation. Spectral markers at 3010, 1520/1238 cm-1 , representative for unsaturation degree of lipids and phosphorylation of tyrosine, respectively, were also affected by perindopril treatment. In conclusion, although metabolic abnormalities associated with type 2 diabetes mellitus such as hypertriglyceridemia and hyperglycemia strongly affected spectral FTIR profile of diabetic plasma, we identified FTIR features that seem to be associated with the vasoprotective activity of ACE-I.
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Affiliation(s)
- Emilia Staniszewska-Slezak
- Faculty of Chemistry, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
| | - Ewelina Wiercigroch
- Faculty of Chemistry, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
| | - Andrzej Fedorowicz
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
- Chair of Pharmacology, Jagiellonian University, Krakow, Poland
| | - Elżbieta Buczek
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
| | - Lukasz Mateuszuk
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
| | - Malgorzata Baranska
- Faculty of Chemistry, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
| | - Stefan Chlopicki
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland
- Chair of Pharmacology, Jagiellonian University, Krakow, Poland
| | - Kamilla Malek
- Faculty of Chemistry, Jagiellonian University, Krakow, Poland
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81
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Profit AA, Desamero RZB. Development of Peptide-Based Inhibitors of Amylin Aggregation Employing Aromatic and Electrostatic Repulsion. Methods Mol Biol 2018; 1824:17-31. [PMID: 30039399 DOI: 10.1007/978-1-4939-8630-9_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Human islet amyloid polypeptide (hIAPP) is a 37-residue hormone that is co-stored and co-secreted with insulin. In type 2 diabetes, the polypeptide misfolds to form amyloid plaques in the pancreas. The self-assembly of hIAPP has been linked to the loss of insulin production and β-cell death. Recent investigations have revealed that soluble oligomers of hIAPP are the cytotoxic species responsible for β-cell death and not insoluble amyloid fibrils. Compounds that prevent the self-assembly of hIAPP or drive self-assembly to the state of innocuous insoluble amyloid may be of potential therapeutic value. In this report we summarize key methods employed in our efforts to identify peptide-based modulators of amylin self-assembly that utilize π-electronic effects or electrostatic charge repulsion. These peptide-based modulators may serve as lead compounds for the development of more drug-like molecules and demonstrate that tuning π-electron density and employing charged amyloid disrupting elements are viable approaches toward the design of potential amyloid inhibitors.
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Affiliation(s)
- Adam A Profit
- Department of Chemistry, York College and The Institute for Macromolecular Assemblies, Jamaica, NY, USA.
- Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA.
| | - Ruel Z B Desamero
- Department of Chemistry, York College and The Institute for Macromolecular Assemblies, Jamaica, NY, USA.
- Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA.
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82
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Seal M, Dey SG. Active-Site Environment of Copper-Bound Human Amylin Relevant to Type 2 Diabetes. Inorg Chem 2017; 57:129-138. [DOI: 10.1021/acs.inorgchem.7b02266] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Manas Seal
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Somdatta Ghosh Dey
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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83
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Rajasekhar K, Narayanaswamy N, Murugan NA, Viccaro K, Lee HG, Shah K, Govindaraju T. Aβ plaque-selective NIR fluorescence probe to differentiate Alzheimer's disease from tauopathies. Biosens Bioelectron 2017; 98:54-61. [PMID: 28649025 PMCID: PMC6370041 DOI: 10.1016/j.bios.2017.06.030] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/01/2017] [Accepted: 06/15/2017] [Indexed: 10/19/2022]
Abstract
Selective detection and staining of toxic amyloid plaques, a potential biomarker present in the Alzheimer's disease (AD) brain is crucial for both clinical diagnosis and monitoring AD disease progression. Herein, we report a coumarin-quinoline (CQ) conjugate-based turn-on near-infrared (NIR) fluorescence probe for specific detection of β-amyloid (Aβ) aggregates. CQ probe is highly sensitive and exhibits ~100-fold fluorescence enhancement in vitro upon binding Aβ aggregates with enhanced quantum yield. Furthermore, the probe has ~10-fold higher binding affinity towards Aβ aggregates (86nM) compared to commonly used Thioflavin T. Most importantly, CQ probe displays unambiguous selectivity towards Aβ aggregates compared to other toxic protein aggregates such as tau, α-synuclein (α-Syn) and islet amyloid polypeptide (IAPP). In addition, CQ is nontoxic to neuronal cells and shows significant blood brain barrier permeability. Remarkably, CQ stains Aβ plaques in human brain tissue over co-existing tau aggregates and neurofibrillary tangles (NFTs), which are associated in AD and tauopathies. This is a highly desirable attribute to distinguish AD from tau pathology and mixed dementia.
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Affiliation(s)
- K Rajasekhar
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
| | - Nagarjun Narayanaswamy
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
| | - N Arul Murugan
- Division of Theoretical Chemistry and Biology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Keith Viccaro
- Department of Chemistry, Purdue University Center for Cancer Research, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Hyoung-Gon Lee
- Department of Biology, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
| | - Kavita Shah
- Department of Chemistry, Purdue University Center for Cancer Research, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Thimmaiah Govindaraju
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India.
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84
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Magrì A, Pietropaolo A, Tabbì G, La Mendola D, Rizzarelli E. From Peptide Fragments to Whole Protein: Copper(II) Load and Coordination Features of IAPP. Chemistry 2017; 23:17898-17902. [PMID: 29111583 DOI: 10.1002/chem.201704910] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Indexed: 12/28/2022]
Abstract
The copper-binding features of rat islet amyloid polypeptide (r-IAPP) are herein disclosed through the determination of the stability constants and spectroscopic properties of its copper complex species. To mimic the metal binding sites of the human IAPP (h-IAPP), a soluble, single-point mutated variant of r-IAPP, having a histidine residue in place of Arg18, was synthesized, that is, r-IAPP(1-37; R18H). The peptide IAPP(1-8) was also characterized to have deeper insight into the N-terminus copper(II)-binding features of r-IAPP as well as of its mutated form. A combined experimental (thermodynamic and spectroscopic) and computational approach allowed us to assess the metal loading and the coordination features of the whole IAPP. At physiological pH, the N-terminal amino group is the Cu2+ main binding site both of entire r-IAPP and of its mutated form that mimics h-IAPP. The histidine residue present in this mutated polypeptide accounts for the second Cu2+ binding. We can speculate that the copper driven toxicity of h-IAPP in comparison to that of r-IAPP can be attributed to the different metal loading and the presence of a second metal anchoring site, the His18 , whose role is usually invoked in the process of h-IAPP aggregation.
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Affiliation(s)
- Antonio Magrì
- Istituto di Biostrutture e Bioimmagini-CNR, Via P. Gaifami 18, 95126, Catania, Italy
| | - Adriana Pietropaolo
- Dipartimento di Scienze della Salute, Università "Magna Graecia" di Catanzaro, Campus Universitario, Viale Europa, 88100, Catanzaro, Italy
| | - Giovanni Tabbì
- Istituto di Biostrutture e Bioimmagini-CNR, Via P. Gaifami 18, 95126, Catania, Italy
| | - Diego La Mendola
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno Pisano 6, 56126, Pisa, Italy
| | - Enrico Rizzarelli
- Istituto di Biostrutture e Bioimmagini-CNR, Via P. Gaifami 18, 95126, Catania, Italy.,Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria, 5, 95125, Catania, Italy
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85
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Ruggeri FS, Habchi J, Cerreta A, Dietler G. AFM-Based Single Molecule Techniques: Unraveling the Amyloid Pathogenic Species. Curr Pharm Des 2017; 22:3950-70. [PMID: 27189600 PMCID: PMC5080865 DOI: 10.2174/1381612822666160518141911] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 05/17/2016] [Indexed: 01/05/2023]
Abstract
Background A wide class of human diseases and neurodegenerative disorders, such as Alzheimer’s disease, is due to the failure of a specific peptide or protein to keep its native functional conformational state and to undergo a conformational change into a misfolded state, triggering the formation of fibrillar cross-β sheet amyloid aggregates. During the fibrillization, several coexisting species are formed, giving rise to a highly heterogeneous mixture. Despite its fundamental role in biological function and malfunction, the mechanism of protein self-assembly and the fundamental origins of the connection between aggregation, cellular toxicity and the biochemistry of neurodegeneration remains challenging to elucidate in molecular detail. In particular, the nature of the specific state of proteins that is most prone to cause cytotoxicity is not established. Methods: In the present review, we present the latest advances obtained by Atomic Force Microscopy (AFM) based techniques to unravel the biophysical properties of amyloid aggregates at the nanoscale. Unraveling amyloid single species biophysical properties still represents a formidable experimental challenge, mainly because of their nanoscale dimensions and heterogeneous nature. Bulk techniques, such as circular dichroism or infrared spectroscopy, are not able to characterize the heterogeneity and inner properties of amyloid aggregates at the single species level, preventing a profound investigation of the correlation between the biophysical properties and toxicity of the individual species. Conclusion: The information delivered by AFM based techniques could be central to study the aggregation pathway of proteins and to design molecules that could interfere with amyloid aggregation delaying the onset of misfolding diseases.
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Affiliation(s)
- Francesco Simone Ruggeri
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, United Kingdom.
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86
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Recombinant human islet amyloid polypeptide forms shorter fibrils and mediates β-cell apoptosis via generation of oxidative stress. Biochem J 2017; 474:3915-3934. [DOI: 10.1042/bcj20170323] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 02/08/2023]
Abstract
Protein misfolding and aggregation play an important role in many human diseases including Alzheimer's, Parkinson's and type 2 diabetes mellitus (T2DM). The human islet amyloid polypeptide (hIAPP) forms amyloid plaques in the pancreas of T2DM subjects (>95%) that are involved in deteriorating islet function and in mediating β-cell apoptosis. However, the detailed mechanism of action, structure and nature of toxic hIAPP species responsible for this effect remains elusive to date mainly due to the high cost associated with the chemical synthesis of pure peptide required for these studies. In the present work, we attempted to obtain structural and mechanistic insights into the hIAPP aggregation process using recombinant hIAPP (rhIAPP) isolated from Escherichia coli. Results from biophysical and structural studies indicate that the rhIAPP self-assembled into highly pure, β-sheet-rich amyloid fibrils with uniform morphology. rhIAPP-mediated apoptosis in INS-1E cells was associated with increased oxidative stress and changes in mitochondrial membrane potential. The transcript levels of apoptotic genes - Caspase-3 and Bax were found to be up-regulated, while the levels of the anti-apoptotic gene - Bcl2 were down-regulated in rhIAPP-treated cells. Additionally, the expression levels of genes involved in combating oxidative stress namely Catalase, SOD1 and GPx were down-regulated. rhIAPP exposure also affected glucose-stimulated insulin secretion from isolated pancreatic islets. The aggregation of rhIAPP also occurred significantly faster when compared with that of the chemically synthesized peptide. We also show that the rhIAPP fibrils were shorter and more cytotoxic. In summary, our study is one among the few to provide comprehensive evaluation of structural, biophysical and cytotoxic properties of rhIAPP.
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87
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Patel P, Parmar K, Vyas VK, Patel D, Das M. Combined in silico approaches for the identification of novel inhibitors of human islet amyloid polypeptide (hIAPP) fibrillation. J Mol Graph Model 2017; 77:295-310. [PMID: 28917147 DOI: 10.1016/j.jmgm.2017.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/01/2017] [Accepted: 09/02/2017] [Indexed: 12/31/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is a natively unfolded polypeptide hormone of glucose metabolism, which is co-secreted with insulin by the β-cells of the pancreas. In patients with type 2 diabetes, IAPP forms amyloid fibrils because of diabetes-associated β-cells dysfunction and increasing fibrillation, in turn, lead to failure of secretory function of β-cells. This provides a target for the discovery of small organic molecules against protein aggregation diseases. However, the binding mechanism of these molecules with monomers, oligomers and fibrils to inhibit fibrillation is still an open question. In this work, ligand and structure-based in silico approaches were used to identify novel fibrillation inhibitors and/or fibril binding compounds. The best pharmacophore model was used as a 3D search query for virtual screening of a compound database to identify novel molecules having the potential to be therapeutic agents against protein aggregation diseases. Docking and molecular dynamics simulation studies were used to explore the interaction pattern and mechanism of the identified novel small molecules with predicted hIAPP structure, its aggregation prone conformation and fibril forming segments. We show that catechins with galloyl group and molecules having two to three planar apolar rings bind to hIAPP structures and fibril forming segments with greater affinity. The differences in binding affinities of different compounds against several fibril forming segments of the peptide suggest that a mixture of active compounds may be required for treatment of aggregation diseases.
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Affiliation(s)
- Palak Patel
- Institute of Science, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India
| | - Krupali Parmar
- Institute of Science, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India
| | - Vivek K Vyas
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India
| | - Dhaval Patel
- Institute of Advanced Research, Koba Institutional Area, Gandhinagar, Gujarat 382007, India
| | - Mili Das
- Institute of Science, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India.
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88
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Pretorius E, Mbotwe S, Kell DB. Lipopolysaccharide-binding protein (LBP) reverses the amyloid state of fibrin seen in plasma of type 2 diabetics with cardiovascular co-morbidities. Sci Rep 2017; 7:9680. [PMID: 28851981 PMCID: PMC5574907 DOI: 10.1038/s41598-017-09860-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 07/31/2017] [Indexed: 12/22/2022] Open
Abstract
Type 2 diabetes (T2D) has many cardiovascular complications, including a thrombotic propensity. Many such chronic, inflammatory diseases are accompanied (and may be exacerbated, and possibly even largely caused) by amyloid fibril formation. Recognising that there are few strong genetic associations underpinning T2D, but that amyloidogenesis of amylin is closely involved, we have been seeking to understand what might trigger the disease. Serum levels of bacterial lipopolysaccharide are raised in T2D, and we recently showed that fibrin(ogen) polymerisation during blood clotting can be affected strongly by LPS. The selectivity was indicated by the regularisation of clotting by lipopolysaccharide-binding protein (LBP). Since coagulopathies are a hallmark of T2D, we wondered whether they might too be caused by LPS (and reversed by LBP). We show here, using SEM and confocal microscopy, that platelet-poor-plasma from subjects with T2D had a much greater propensity for hypercoagulability and for amyloidogenesis, and that these could both be reversed by LBP. These data imply that coagulopathies are an important feature of T2D, and may be driven by ‘hidden’ LPS. Given the prevalence of amyloid formation in the sequelae of diabetes, this opens up novel strategies for both the prevention and treatment of T2D.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch Private Bag X1 MATIELAND, 7602, Stellenbosch, South Africa.
| | - Sthembile Mbotwe
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, 0007, South Africa
| | - Douglas B Kell
- School of Chemistry, The University of Manchester, 131 Princess St, MANCHESTER M1 7DN, Lancs, UK. .,Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, MANCHESTER M1 7DN, Lancs, UK. .,Centre for Synthetic Biology of Fine and Speciality Chemicals, The University of Manchester, 131 Princess St, MANCHESTER M1 7DN, Lancs, UK.
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89
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Sequeira IR, Poppitt SD. Unfolding Novel Mechanisms of Polyphenol Flavonoids for Better Glycaemic Control: Targeting Pancreatic Islet Amyloid Polypeptide (IAPP). Nutrients 2017; 9:E788. [PMID: 28754022 PMCID: PMC5537902 DOI: 10.3390/nu9070788] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/12/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022] Open
Abstract
Type 2 diabetes (T2D) is characterised by hyperglycaemia resulting from defective insulin secretion, insulin resistance, or both. The impact of over-nutrition and reduced physical activity, evidenced by the exponential rise in obesity and the prevalence of T2D, strongly supports the implementation of lifestyle modification programs. Accordingly, an increased consumption of fruits and plant-derived foods has been advocated, as their intake is inversely correlated with T2D prevalence; this has been attributed, in part, to their contained polyphenolic compounds. Over the last decade, a body of work has focussed on establishing the mechanisms by which polyphenolic compounds exert beneficial effects to limit carbohydrate digestion, enhance insulin-mediated glucose uptake, down-regulate hepatic gluconeogenesis and decrease oxidative stress; the latter anti-oxidative property being the most documented. Novel effects on the inhibition of glucocorticoid action and the suppression of amylin misfolding and aggregation have been identified more recently. Amyloid fibrils form from spontaneously misfolded amylin, depositing in islet cells to elicit apoptosis, beta cell degeneration and decrease insulin secretion, with amyloidosis affecting up to 80% of pancreatic islet cells in T2D. Therefore, intervening with polyphenolic compounds offers a novel approach to suppressing risk or progression to T2D. This review gives an update on the emerging mechanisms related to dietary polyphenol intake for the maintenance of glycaemic control and the prevention of T2D.
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Affiliation(s)
- Ivana R Sequeira
- Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland 1142, New Zealand.
| | - Sally D Poppitt
- Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland 1142, New Zealand.
- Department of Medicine, University of Auckland, Auckland 1142, New Zealand.
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90
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Tracking the amyloidogenic core of IAPP amyloid fibrils: Insights from micro-Raman spectroscopy. J Struct Biol 2017; 199:140-152. [PMID: 28602716 DOI: 10.1016/j.jsb.2017.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/19/2017] [Accepted: 06/03/2017] [Indexed: 12/14/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is the major protein component of extracellular amyloid deposits, located in the islets of Langerhans, a hallmark of type II diabetes. The underlying mechanisms of IAPP aggregation have not yet been clearly defined, although the highly amyloidogenic sequence of the protein has been extensively studied. Several segments have been highlighted as aggregation-prone regions (APRs), with much attention focused on the central 8-17 and 20-29 stretches. In this work, we employ micro-Raman spectroscopy to identify specific regions that are contributing to or are excluded from the amyloidogenic core of IAPP amyloid fibrils. Our results demonstrate that both the N-terminal region containing a conserved disulfide bond between Cys residues at positions 2 and 7, and the C-terminal region containing the only Tyr residue are excluded from the amyloid core. Finally, by performing detailed aggregation assays and molecular dynamics simulations on a number of IAPP variants, we demonstrate that point mutations within the central APRs contribute to the reduction of the overall amyloidogenic potential of the protein but do not completely abolish the formation of IAPP amyloid fibrils.
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91
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Prabakaran R, Goel D, Kumar S, Gromiha MM. Aggregation prone regions in human proteome: Insights from large-scale data analyses. Proteins 2017; 85:1099-1118. [DOI: 10.1002/prot.25276] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 02/10/2017] [Accepted: 02/24/2017] [Indexed: 12/25/2022]
Affiliation(s)
- R. Prabakaran
- Department of Biotechnology, Bhupat Jyoti Mehta School of Biosciences; Indian Institute of Technology Madras; Chennai 600036 India
| | - Dhruv Goel
- Department of Computer Science and Engineering; Motilal Nehru National Institute of Technology; Allahabad 211004 India
| | - Sandeep Kumar
- Biotherapeutics Pharmaceutical Sciences, Pfizer Inc; 700 Chesterfield Parkway West Chesterfield Missouri 63017, USA
| | - M. Michael Gromiha
- Department of Biotechnology, Bhupat Jyoti Mehta School of Biosciences; Indian Institute of Technology Madras; Chennai 600036 India
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92
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Zhang Y, Song W. Islet amyloid polypeptide: Another key molecule in Alzheimer's pathogenesis? Prog Neurobiol 2017; 153:100-120. [PMID: 28274676 DOI: 10.1016/j.pneurobio.2017.03.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 02/17/2017] [Accepted: 03/02/2017] [Indexed: 12/14/2022]
Abstract
Recent epidemiological evidence reveals that patients suffering from type 2 diabetes mellitus (T2DM) often experience a significant decline in cognitive function, and approximately 70% of those cases eventually develop Alzheimer's disease (AD). Although several pathological processes are shared by AD and T2DM, the exact molecular mechanisms connecting these two diseases are poorly understood. Aggregation of human islet amyloid polypeptide (hIAPP), the pathological hallmark of T2DM, has also been detected in brain tissue and is associated with cognitive decline and AD development. In addition, hIAPP and amyloid β protein (Aβ) share many biophysical and physiological properties as well as exert similar cytotoxic mechanisms. Therefore, it is important to examine the possible role of hIAPP in the pathogenesis of AD. In this article, we introduce the basics on this amyloidogenic protein. More importantly, we discuss the potential mechanisms of hIAPP-induced AD development, which will be beneficial for proposing novel and feasible strategies to optimize AD prevention and/or treatment in diabetics.
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Affiliation(s)
- Yun Zhang
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Weihong Song
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada.
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93
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Wang ST, Lin Y, Todorova N, Xu Y, Mazo M, Rana S, Leonardo V, Amdursky N, Spicer CD, Alexander BD, Edwards AA, Matthews SJ, Yarovsky I, Stevens MM. Facet-Dependent Interactions of Islet Amyloid Polypeptide with Gold Nanoparticles: Implications for Fibril Formation and Peptide-Induced Lipid Membrane Disruption. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2017; 29:1550-1560. [PMID: 28260837 PMCID: PMC5333186 DOI: 10.1021/acs.chemmater.6b04144] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/25/2017] [Indexed: 05/03/2023]
Abstract
A comprehensive understanding of the mechanisms of interaction between proteins or peptides and nanomaterials is crucial for the development of nanomaterial-based diagnostics and therapeutics. In this work, we systematically explored the interactions between citrate-capped gold nanoparticles (AuNPs) and islet amyloid polypeptide (IAPP), a 37-amino acid peptide hormone co-secreted with insulin from the pancreatic islet. We utilized diffusion-ordered spectroscopy, isothermal titration calorimetry, localized surface plasmon resonance spectroscopy, gel electrophoresis, atomic force microscopy, transmission electron microscopy (TEM), and molecular dynamics (MD) simulations to systematically elucidate the underlying mechanism of the IAPP-AuNP interactions. Because of the presence of a metal-binding sequence motif in the hydrophilic peptide domain, IAPP strongly interacts with the Au surface in both the monomeric and fibrillar states. Circular dichroism showed that AuNPs triggered the IAPP conformational transition from random coil to ordered structures (α-helix and β-sheet), and TEM imaging suggested the acceleration of IAPP fibrillation in the presence of AuNPs. MD simulations revealed that the IAPP-AuNP interactions were initiated by the N-terminal domain (IAPP residues 1-19), which subsequently induced a facet-dependent conformational change in IAPP. On a Au(111) surface, IAPP was unfolded and adsorbed directly onto the Au surface, while for the Au(100) surface, it interacted predominantly with the citrate adlayer and retained some helical conformation. The observed affinity of AuNPs for IAPP was further applied to reduce the level of peptide-induced lipid membrane disruption.
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Affiliation(s)
- Shih-Ting Wang
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
| | - Yiyang Lin
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
| | - Nevena Todorova
- School
of Engineering, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia
| | - Yingqi Xu
- Department
of Life Sciences, Imperial College London, London SW7 2AZ, U.K.
| | - Manuel Mazo
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
| | - Subinoy Rana
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
| | - Vincent Leonardo
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
| | - Nadav Amdursky
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
| | - Christopher D. Spicer
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
| | - Bruce D. Alexander
- Department
of Pharmaceutical, Chemical and Environmental Science, University of Greenwich, Central Avenue, Chatham, Kent ME4 4TB, U.K.
| | - Alison A. Edwards
- Medway School
of Pharmacy, Universities of Kent and Greenwich
at Medway, Central Avenue, Chatham, Kent ME4 4TB, U.K.
| | - Steve J. Matthews
- Department
of Life Sciences, Imperial College London, London SW7 2AZ, U.K.
| | - Irene Yarovsky
- School
of Engineering, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia
| | - Molly M. Stevens
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K.
- E-mail:
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94
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Tran L, Ha-Duong T. Effect of Post-Translational Amidation on Islet Amyloid Polypeptide Conformational Ensemble: Implications for Its Aggregation Early Steps. Int J Mol Sci 2016; 17:ijms17111896. [PMID: 27854243 PMCID: PMC5133895 DOI: 10.3390/ijms17111896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/02/2016] [Accepted: 11/09/2016] [Indexed: 12/21/2022] Open
Abstract
The human islet amyloid polypeptide (hIAPP) is an intrinsically disordered protein that can self-assemble into fibrillar aggregates that play a key role in the pathogenesis of the type II diabetes mellitus. hIAPP can transiently adopt α-helix and β-strand conformations that could be important intermediate species on the fibrillization pathway. However, experimental studies of the monomeric peptide conformations are limited due to its high aggregation propensity, and the early steps of the hIAPP association are not clearly characterized. In particular, the question of whether the aggregation-prone conformation is α-helical or β-strand-rich is still debated. In this study, combining extensive all-atom molecular dynamics (MD) and replica exchange molecular dynamics (REMD) simulations in explicit water, we shed some light on the differences between the amidated and non-amidated hIAPP conformational ensembles. Our study shows that, when compared to the amidated monomer, the non-amidation of hIAPP induces a significantly lower propensity to form β-strands, especially aggregation-prone β-hairpins. Since the fibrillization of the non-amidated hIAPP is significantly slower than that of the amidated peptide, this indicates that the early steps of the peptide oligomerization involve the association of β-hairpins or β-strands structures.
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Affiliation(s)
- Linh Tran
- BioCIS, Université Paris-Sud, CNRS, Université Paris-Saclay, 92290 Châtenay-Malabry, France.
| | - Tâp Ha-Duong
- BioCIS, Université Paris-Sud, CNRS, Université Paris-Saclay, 92290 Châtenay-Malabry, France.
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95
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Receptor-mediated toxicity of human amylin fragment aggregated by short- and long-term incubations with copper ions. Mol Cell Biochem 2016; 425:85-93. [PMID: 27804051 DOI: 10.1007/s11010-016-2864-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/22/2016] [Indexed: 12/29/2022]
Abstract
Human amylin (hA1-37) is a polypeptide hormone secreted in conjunction with insulin from the pancreatic β-cells involved in the pathogenesis of type 2 diabetes mellitus (T2DM). The shorter fragment hA17-29 than full-length peptide is capable to form amyloids "in vitro". Here, we monitored the time course of hA17-29 β-amyloid fibril and oligomer formation [without and with copper(II)], cellular toxicity of different amyloid aggregates, and involvement of specific receptors (receptor for advanced glycation end-products, RAGE; low-affinity nerve growth factor receptor, p75-NGFR) in aggregate toxicity. Fibril and oligomer formation of hA17-29 incubated at 37 °C for 0, 48, and 120 h, without or with copper(II), were measured by the thioflavin T fluorescence assay and ELISA, respectively. Toxicity of hA17-29 aggregates and effects of anti-RAGE and anti-p75-NGFR antibodies were evaluated on neuroblastoma SH-SY5Y viability. Fluorescence assay of hA17-29 indicates an initial slow rate of soluble fibril formation (48 h), followed by a slower rate of insoluble aggregate formation (120 h). The highest quantity of oligomers was recorded when hA17-29 was pre-aggregated for 48 h in the presence of copper(II) showing also the maximal cell toxicity (-44% of cell viability, p < 0.01 compared to controls). Anti-RAGE or anti-p75-NGFR antibodies almost abolished cell toxicity of hA17-29 aggregates. These results indicate that copper(II) influences the aggregation process and hA17-29 toxicities are especially attributable to oligomeric aggregates. hA17-29 aggregate toxicity seems to be mediated by RAGE and p75-NGFR receptors which might be potential targets for new drugs in T2DM treatment.
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96
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Provvisiero DP, Pivonello C, Muscogiuri G, Negri M, de Angelis C, Simeoli C, Pivonello R, Colao A. Influence of Bisphenol A on Type 2 Diabetes Mellitus. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:E989. [PMID: 27782064 PMCID: PMC5086728 DOI: 10.3390/ijerph13100989] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 09/28/2016] [Indexed: 12/13/2022]
Abstract
Bisphenol A (BPA) is an organic synthetic compound employed to produce plastics and epoxy resins. It is used as a structural component in polycarbonate beverage bottles and as coating for metal surface in food containers and packaging. The adverse effects of BPA on human health are widely disputed. BPA has been recently associated with a wide variety of medical disorders and, in particular, it was identified as potential endocrine-disrupting compound with diabetogenic action. Most of the clinical observational studies in humans reveal a positive link between BPA exposure, evaluated by the measurement of urinary BPA levels, and the risk of developing type 2 diabetes mellitus. Clinical studies on humans and preclinical studies on in vivo, ex vivo, and in vitro models indicate that BPA, mostly at low doses, may have a role in increasing type 2 diabetes mellitus developmental risk, directly acting on pancreatic cells, in which BPA induces the impairment of insulin and glucagon secretion, triggers inhibition of cell growth and apoptosis, and acts on muscle, hepatic, and adipose cell function, triggering an insulin-resistant state. The current review summarizes the available evidences regarding the association between BPA and type 2 diabetes mellitus, focusing on both clinical and preclinical studies.
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Affiliation(s)
| | - Claudia Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Università di Napoli “Federico II”, Naples 80130, Italy; (C.P.); (C.S.); (A.C.)
| | - Giovanna Muscogiuri
- I.O.S. & COLEMAN S.r.l., Naples 80100, Italy; (D.P.P.); (G.M.); (M.N.); (C.d.A.)
| | - Mariarosaria Negri
- I.O.S. & COLEMAN S.r.l., Naples 80100, Italy; (D.P.P.); (G.M.); (M.N.); (C.d.A.)
| | - Cristina de Angelis
- I.O.S. & COLEMAN S.r.l., Naples 80100, Italy; (D.P.P.); (G.M.); (M.N.); (C.d.A.)
| | - Chiara Simeoli
- Dipartimento di Medicina Clinica e Chirurgia, Università di Napoli “Federico II”, Naples 80130, Italy; (C.P.); (C.S.); (A.C.)
| | - Rosario Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Università di Napoli “Federico II”, Naples 80130, Italy; (C.P.); (C.S.); (A.C.)
| | - Annamaria Colao
- Dipartimento di Medicina Clinica e Chirurgia, Università di Napoli “Federico II”, Naples 80130, Italy; (C.P.); (C.S.); (A.C.)
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97
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Sánchez-López C, Cortés-Mejía R, Miotto MC, Binolfi A, Fernández CO, Del Campo JM, Quintanar L. Copper Coordination Features of Human Islet Amyloid Polypeptide: The Type 2 Diabetes Peptide. Inorg Chem 2016; 55:10727-10740. [PMID: 27704849 DOI: 10.1021/acs.inorgchem.6b01963] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is the major component of amyloid deposits found in pancreatic β-cells of patients with type 2 diabetes (T2D). Copper ions have an inhibitory effect on the amyloid aggregation of hIAPP, and they may play a role in the etiology of T2D. However, deeper knowledge of the structural details of the copper-hIAPP interaction is required to understand the molecular mechanisms involved. Here, we performed a spectroscopic study of Cu(II) binding to hIAPP and several variants, using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), electronic absorption, and circular dichroism (CD) in the UV-vis region in combination with Born-Oppenheimer molecular dynamics (BOMD) and density functional theory geometry optimizations. We find that Cu(II) binds to the imidazole N1 of His18, the deprotonated amides of Ser19 and Ser20, and an oxygen-based ligand provided by Ser20, either via its hydroxyl group or its backbone carbonyl, while Asn22 might also play a role as an axial ligand. Ser20 plays a crucial role in stabilizing Cu(II) coordination toward the C-terminal, providing a potential link between the S20G mutation associated with early onset of T2D, its impact in Cu binding properties, and hIAPP amyloid aggregation. Our study defines the nature of the coordination environment in the Cu(II)-hIAPP complex, revealing that the amino acid residues involved in metal ion binding are also key residues for the formation of β-sheet structures and amyloid fibrils. Cu(II) binding to hIAPP may lead to the coexistence of more than one coordination mode, which in turn could favor different sets of Cu-induced conformational ensembles. Cu-induced hIAPP conformers would display a higher energetic barrier to form amyloid fibrils, hence explaining the inhibitory effect of Cu ions in hIAPP aggregation. Overall, this study provides further structural insights into the bioinorganic chemistry of T2D.
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Affiliation(s)
- Carolina Sánchez-López
- Departamento de Química, Centro de Investigación y de Estudios Avanzados (Cinvestav) , Mexico City, Mexico
| | - Rodrigo Cortés-Mejía
- Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM) , Mexico City, Mexico
| | - Marco C Miotto
- Max Planck Laboratory for Structural Biology, Chemistry and Molecular Biophysics of Rosario (MPLbioR, UNR-MPIbpC) and Instituto de Investigaciones para el Descubrimiento de Fármacos de Rosario (IIDEFAR, UNR-CONICET), Universidad Nacional de Rosario , Ocampo y Esmeralda, S2002LRK Rosario, Argentina
| | - Andres Binolfi
- Max Planck Laboratory for Structural Biology, Chemistry and Molecular Biophysics of Rosario (MPLbioR, UNR-MPIbpC) and Instituto de Investigaciones para el Descubrimiento de Fármacos de Rosario (IIDEFAR, UNR-CONICET), Universidad Nacional de Rosario , Ocampo y Esmeralda, S2002LRK Rosario, Argentina
| | - Claudio O Fernández
- Max Planck Laboratory for Structural Biology, Chemistry and Molecular Biophysics of Rosario (MPLbioR, UNR-MPIbpC) and Instituto de Investigaciones para el Descubrimiento de Fármacos de Rosario (IIDEFAR, UNR-CONICET), Universidad Nacional de Rosario , Ocampo y Esmeralda, S2002LRK Rosario, Argentina
| | - Jorge M Del Campo
- Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM) , Mexico City, Mexico
| | - Liliana Quintanar
- Departamento de Química, Centro de Investigación y de Estudios Avanzados (Cinvestav) , Mexico City, Mexico
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98
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Structural Characterization of Fibrils from Recombinant Human Islet Amyloid Polypeptide by Solid-State NMR: The Central FGAILS Segment Is Part of the β-Sheet Core. PLoS One 2016; 11:e0161243. [PMID: 27607147 PMCID: PMC5015977 DOI: 10.1371/journal.pone.0161243] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/02/2016] [Indexed: 11/19/2022] Open
Abstract
Amyloid deposits formed from islet amyloid polypeptide (IAPP) are a hallmark of type 2 diabetes mellitus and are known to be cytotoxic to pancreatic β-cells. The molecular structure of the fibrillar form of IAPP is subject of intense research, and to date, different models exist. We present results of solid-state NMR experiments on fibrils of recombinantly expressed and uniformly 13C, 15N-labeled human IAPP in the non-amidated, free acid form. Complete sequential resonance assignments and resulting constraints on secondary structure are shown. A single set of chemical shifts is found for most residues, which is indicative of a high degree of homogeneity. The core region comprises three to four β-sheets. We find that the central 23-FGAILS-28 segment, which is of critical importance for amyloid formation, is part of the core region and forms a β-strand in our sample preparation. The eight N-terminal amino acid residues of IAPP, forming a ring-like structure due to a disulfide bridge between residues C2 and C7, appear to be well defined but with an increased degree of flexibility. This study supports the elucidation of the structural basis of IAPP amyloid formation and highlights the extent of amyloid fibril polymorphism.
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99
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Hogan MF, Meier DT, Zraika S, Templin AT, Mellati M, Hull RL, Leissring MA, Kahn SE. Inhibition of Insulin-Degrading Enzyme Does Not Increase Islet Amyloid Deposition in Vitro. Endocrinology 2016; 157:3462-8. [PMID: 27404391 PMCID: PMC5007890 DOI: 10.1210/en.2016-1410] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Islet amyloid deposition in human type 2 diabetes results in β-cell loss. These amyloid deposits contain the unique amyloidogenic peptide human islet amyloid polypeptide (hIAPP), which is also a known substrate of the protease insulin-degrading enzyme (IDE). Whereas IDE inhibition has recently been demonstrated to improve glucose metabolism in mice, inhibiting it has also been shown to increase cell death when synthetic hIAPP is applied exogenously to a β-cell line. Thus, we wanted to determine whether a similar deleterious effect is observed when hIAPP is endogenously produced and secreted from islets. To address this issue, we cultured hIAPP transgenic mouse islets that have the propensity to form amyloid for 48 and 144 hours in 16.7 mM glucose in the presence and absence of the IDE inhibitor 1. At neither time interval did IDE inhibition increase amyloid formation or β-cell loss. Thus, the inhibition of IDE may represent an approach to improve glucose metabolism in human type 2 diabetes, without inducing amyloid deposition and its deleterious effects.
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Affiliation(s)
- Meghan F Hogan
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
| | - Daniel T Meier
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
| | - Sakeneh Zraika
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
| | - Andrew T Templin
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
| | - Mahnaz Mellati
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
| | - Rebecca L Hull
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
| | - Malcolm A Leissring
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
| | - Steven E Kahn
- Division of Metabolism, Endocrinology, and Nutrition (M.F.H., D.T.M., S.Z., A.T.T., M.M., R.L.H., S.E.K.), Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington 98108; and Institute for Memory Impairments and Neurological Disorders (M.A.L.), University of California, Irvine, Irvine, California 92697
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100
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Yu XL, Li YN, Zhang H, Su YJ, Zhou WW, Zhang ZP, Wang SW, Xu PX, Wang YJ, Liu RT. Rutin inhibits amylin-induced neurocytotoxicity and oxidative stress. Food Funct 2016; 6:3296-306. [PMID: 26242245 DOI: 10.1039/c5fo00500k] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Recent evidence showed that amylin deposition is not only found in the pancreas in type 2 diabetes mellitus (T2DM) patients, but also in other peripheral organs, such as kidneys, heart and brain. Circulating amylin oligomers that cross the blood-brain barrier and accumulate in the brain may be an important contributor to diabetic cerebral injury and neurodegeneration. Moreover, increasing epidemiological studies indicate that there is a significant association between T2DM and Alzheimer's disease (AD). Amylin and β-amyloid (Aβ) may share common pathophysiology and show strikingly similar neurotoxicity profiles in the brain. To explore the potential effects of rutin on AD, we here investigated the effect of rutin on amylin aggregation by thioflavin T dyeing, evaluated the effect of rutin on amylin-induced neurocytotoxicity by the MTT assay, and assessed oxidative stress, as well as the generation of nitric oxide (NO) and pro-inflammatory cytokines in neuronal cells. Our results showed that the flavonoid antioxidant rutin inhibited amylin-induced neurocytotoxicity, decreased the production of reactive oxygen species (ROS), NO, glutathione disulfide (GSSG), malondialdehyde (MDA) and pro-inflammatory cytokines TNF-α and IL-1β, attenuated mitochondrial damage and increased the GSH/GSSG ratio. These protective effects of rutin may have resulted from its ability to inhibit amylin aggregation, enhance the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and reduce inducible nitric oxide synthase (iNOS) activity. These in vitro results indicate that rutin is a promising natural product for protecting neuronal cells from amylin-induced neurotoxicity and oxidative stress, and rutin administration could be a feasible therapeutic strategy for preventing AD development and protecting the aging brain or slowing neurodegenerative processes.
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Affiliation(s)
- Xiao-Lin Yu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
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