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Niedziałkowski P, Jurczak P, Orlikowska M, Wcisło A, Ryl J, Ossowski T, Czaplewska P. Phospholipid-functionalized gold electrode for cellular membrane interface studies - interactions between DMPC bilayer and human cystatin C. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184266. [PMID: 38151198 DOI: 10.1016/j.bbamem.2023.184266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 12/29/2023]
Abstract
This work describes the electrochemical studies on the interactions between V57G mutant of human cystatin C (hCC V57G) and membrane bilayer immobilized on the surface of a gold electrode. The electrode was modified with 6-mercaptohexan-1-ol (MCH) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). DMPC was used as a membrane mimetic for monitoring electrochemical changes resulting from the interactions between the functionalized electrode surface and human cystatin C. The interactions between the modified electrode and hCC V57G were investigated by cyclic voltammetry and electrochemical impedance spectroscopy in a phosphate buffered saline (PBS) containing Fe(CN)63-/4- as a redox probe. The electrochemical measurements confirm that fabricated electrode is sensitive to hCC V57G at the concentration of 1 × 10-14 M. The incubation studies carried out at higher concentrations resulted in insignificant changes observed in cyclic voltammetry and electrochemical impedance spectroscopy measurements. The calculated values of surface coverage θR confirm that the electrode is equally covered at higher concentrations of hCC V57G. Measurements of wettability and surface free energy made it possible to determine the influence of individual structural elements of the modified gold electrode on its properties, and thus allowed to understand the nature of the interactions. Contact angle values confirmed the results obtained during electrochemical measurements, indicating the sensitivity of the electrode towards hCC V57G at the concentration of 1 × 10-14 M. In addition, the XPS spectra confirmed the successful anchoring of hCC V57G to the DMPC-functionalized surface.
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Affiliation(s)
- Paweł Niedziałkowski
- Department of Analytical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdańsk 80-308, Poland.
| | - Przemysław Jurczak
- Department of Biomedical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdańsk 80-308, Poland; Specialist Laboratories, Intercollegiate Faculty of Biotechnology UG&MUG, Abrahama 58, Gdańsk 80-307, Poland.
| | - Marta Orlikowska
- Department of Biomedical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Anna Wcisło
- Department of Analytical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Jacek Ryl
- Division of Electrochemistry and Surface Physical Chemistry, Institute of Nanotechnology and Materials Engineering and Advanced Materials Center, Gdańsk University of Technology, Narutowicza 11/12, Gdańsk 80-233, Poland
| | - Tadeusz Ossowski
- Department of Analytical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Paulina Czaplewska
- Specialist Laboratories, Intercollegiate Faculty of Biotechnology UG&MUG, Abrahama 58, Gdańsk 80-307, Poland
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Shi A, Long Y, Ma Y, Yu S, Li D, Deng J, Wen J, Li X, Wu Y, He X, Hu Y, Li N, Hu Y. Natural essential oils derived from herbal medicines: A promising therapy strategy for treating cognitive impairment. Front Aging Neurosci 2023; 15:1104269. [PMID: 37009463 PMCID: PMC10060871 DOI: 10.3389/fnagi.2023.1104269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 02/21/2023] [Indexed: 03/18/2023] Open
Abstract
Cognitive impairment (CI), mainly Alzheimer’s disease (AD), continues to increase in prevalence and is emerging as one of the major health problems in society. However, until now, there are no first-line therapeutic agents for the allopathic treatment or reversal of the disease course. Therefore, the development of therapeutic modalities or drugs that are effective, easy to use, and suitable for long-term administration is important for the treatment of CI such as AD. Essential oils (EOs) extracted from natural herbs have a wide range of pharmacological components, low toxicity, and wide sources, In this review, we list the history of using volatile oils against cognitive disorders in several countries, summarize EOs and monomeric components with cognitive improvement effects, and find that they mainly act by attenuating the neurotoxicity of amyloid beta, anti-oxidative stress, modulating the central cholinergic system, and improving microglia-mediated neuroinflammation. And combined with aromatherapy, the unique advantages and potential of natural EOs in the treatment of AD and other disorders were discussed. This review hopes to provide scientific basis and new ideas for the development and application of natural medicine EOs in the treatment of CI.
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Affiliation(s)
- Ai Shi
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yu Long
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yin Ma
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Shuang Yu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Dan Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jie Deng
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jing Wen
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaoqiu Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yuanyuan Wu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaofang He
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yue Hu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Nan Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- *Correspondence: Nan Li,
| | - Yuan Hu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Yuan Hu,
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Ma L, Li X, Petersen RB, Peng A, Huang K. Probing the interactions between amyloidogenic proteins and bio-membranes. Biophys Chem 2023; 296:106984. [PMID: 36889133 DOI: 10.1016/j.bpc.2023.106984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/11/2023] [Accepted: 02/22/2023] [Indexed: 03/01/2023]
Abstract
Protein misfolding diseases (PMDs) in humans are characterized by the deposition of protein aggregates in tissues, including Alzheimer's disease, Parkinson's disease, type 2 diabetes, and amyotrophic lateral sclerosis. Misfolding and aggregation of amyloidogenic proteins play a central role in the onset and progression of PMDs, and these processes are regulated by multiple factors, especially the interaction between proteins and bio-membranes. Bio-membranes induce conformational changes in amyloidogenic proteins and affect their aggregation; on the other hand, the aggregates of amyloidogenic proteins may cause membrane damage or dysfunction leading to cytotoxicity. In this review, we summarize the factors that affect the binding of amyloidogenic proteins and membranes, the effects of bio-membranes on the aggregation of amyloidogenic proteins, mechanisms of membrane disruption by amyloidogenic aggregates, technical approaches for detecting these interactions, and finally therapeutic strategies targeting membrane damage caused by amyloidogenic proteins.
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Affiliation(s)
- Liang Ma
- Department of Pharmacy, Wuhan Mental Health Center, Wuhan, China; Department of Pharmacy, Wuhan Hospital for Psychotherapy, Wuhan, China
| | - Xi Li
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Robert B Petersen
- Foundational Sciences, Central Michigan University College of Medicine, Mount Pleasant, MI, USA
| | - Anlin Peng
- Department of Pharmacy, The Third Hospital of Wuhan, Tongren Hospital of Wuhan University, Wuhan, China.
| | - Kun Huang
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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Dicke SS, Maj M, Fields CR, Zanni MT. Metastable intermediate during hIAPP aggregation catalyzed by membranes as detected with 2D IR spectroscopy. RSC Chem Biol 2022; 3:931-940. [PMID: 35866164 PMCID: PMC9257649 DOI: 10.1039/d2cb00028h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
Abstract
The aggregation of human islet amyloid polypeptide (hIAPP) into amyloid fibrils involves formation of oligomeric intermediates that are thought to be the cytotoxic species responsible for β-cell dysfunction in type 2 diabetes. hIAPP oligomers permeating or disrupting the cellular membrane may be one mechanism of toxicity and so measuring the structural kinetics of aggregation in the presence of membranes is of much interest. In this study, we use 2D IR spectroscopy and 13C18O isotope labeling to study the secondary structure of the oligomeric intermediates formed in solution and in the presence of phospholipid vesicles at sites L12A13, L16V17, G24A25 and V32G33. Pairs of labels monitor the couplings between associated polypeptides and the dihedral angles between adjacent residues. In solution, the L12A13 residues form an oligomeric β-sheet in addition to an α-helix whereas with the phospholipid vesicles they are α-helical throughout the aggregation process. In both solution and with DOPC vesicles, L16V17 and V32G33 have disordered structures until fibrils are formed. Similarly, under both conditions, G24A25 exhibits 3-state kinetics, created by an oligomeric intermediate with a well-defined β-sheet structure. Amyloid fibril formation is often thought to involve intermediates with exceedingly low populations that are difficult to detect experimentally. These experiments establish that amyloid fibril formation of hIAPP when catalyzed by membranes includes a metastable intermediate and that this intermediate has a similar structure at G24A25 in the FGAIL region as the corresponding intermediate in solution, thought to be the toxic species. 2D IR and 13C18O isotope labeling establish that amyloid formation of hIAPP catalyzed by membranes includes a metastable intermediate with a similar structure at G24A25 in the FGAIL region as the corresponding intermediate in solution.![]()
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Affiliation(s)
- Sidney S Dicke
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Michał Maj
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA .,Formally at Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Caitlyn R Fields
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
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5
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Single-molecule studies of amyloid proteins: from biophysical properties to diagnostic perspectives. Q Rev Biophys 2020; 53:e12. [PMID: 33148356 DOI: 10.1017/s0033583520000086] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In neurodegenerative diseases, a wide range of amyloid proteins or peptides such as amyloid-beta and α-synuclein fail to keep native functional conformations, followed by misfolding and self-assembling into a diverse array of aggregates. The aggregates further exert toxicity leading to the dysfunction, degeneration and loss of cells in the affected organs. Due to the disordered structure of the amyloid proteins, endogenous molecules, such as lipids, are prone to interact with amyloid proteins at a low concentration and influence amyloid cytotoxicity. The heterogeneity of amyloid proteinscomplicates the understanding of the amyloid cytotoxicity when relying only on conventional bulk and ensemble techniques. As complementary tools, single-molecule techniques (SMTs) provide novel insights into the different subpopulations of a heterogeneous amyloid mixture as well as the cytotoxicity, in particular as involved in lipid membranes. This review focuses on the recent advances of a series of SMTs, including single-molecule fluorescence imaging, single-molecule force spectroscopy and single-nanopore electrical recording, for the understanding of the amyloid molecular mechanism. The working principles, benefits and limitations of each technique are discussed and compared in amyloid protein related studies.. We also discuss why SMTs show great potential and are worthy of further investigation with feasibility studies as diagnostic tools of neurodegenerative diseases and which limitations are to be addressed.
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Xi XX, Sun J, Chen HC, Chen AD, Gao LP, Yin J, Jing YH. High-Fat Diet Increases Amylin Accumulation in the Hippocampus and Accelerates Brain Aging in hIAPP Transgenic Mice. Front Aging Neurosci 2019; 11:225. [PMID: 31507407 PMCID: PMC6718729 DOI: 10.3389/fnagi.2019.00225] [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] [Received: 04/29/2019] [Accepted: 08/08/2019] [Indexed: 12/23/2022] Open
Abstract
The accumulation of human islet amyloid polypeptide (hIAPP) in pancreatic islets under induction by a high-fat diet plays a critical role in the development of type-2 diabetes mellitus (T2DM). T2DM is a risk factor of late-onset Alzheimer’s disease (AD). Nevertheless, whether hIAPP in combination with hyperlipidemia may lead to AD-like pathological changes in the brain remains unclear. hIAPP transgenic mice were fed with a high-fat diet for 6 or 12 months to establish the T2DM model. The accumulation of amylin, the numbers of Fluoro-Jade C (FJC)-positive and β-gal positive cells, and the deposition level of Aβ42 in the hippocampi of the transgenic mice were detected by using brain sections. Cytoplasmic and membrane proteins were extracted from the hippocampi of the transgenic mice, and the ratio of membrane GLUT4 expression to cytoplasmic GLUT4 expression was measured through Western blot analysis. Changes in the cognitive functions of hIAPP transgenic mice after 12 months of feeding with a high-fat diet were evaluated. hIAPP transgenic mice fed with a high-fat diet for 6 or 12 months showed elevated blood glucose levels and insulin resistance; increased amylin accumulation, number of FJC-positive and β-gal positive cells, and Aβ42 deposition in the hippocampi; and reduced membrane GLUT4 expression levels. hIAPP transgenic mice fed with a high-fat diet for 12 months showed reductions in social cognitive ability and passive learning ability. A high-fat diet increased amylin accumulation in the hippocampi of hIAPP transgenic mice, which presented AD-like pathology and behavior characterized by neural degeneration, brain aging, Aβ42 deposition, and impaired glucose utilization and cognition.
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Affiliation(s)
- Xiao-Xia Xi
- Center of Experimental Animal, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Jing Sun
- Center of Experimental Animal, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Hai-Chao Chen
- School of Basic Medical Sciences, Institute of Anatomy and Histology & Embryology, Neuroscience, Lanzhou University, Lanzhou, China
| | - An-Di Chen
- School of Basic Medical Sciences, Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou, China
| | - Li-Ping Gao
- School of Basic Medical Sciences, Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou, China
| | - Jie Yin
- School of Basic Medical Sciences, Institute of Anatomy and Histology & Embryology, Neuroscience, Lanzhou University, Lanzhou, China
| | - Yu-Hong Jing
- School of Basic Medical Sciences, Institute of Anatomy and Histology & Embryology, Neuroscience, Lanzhou University, Lanzhou, China.,Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
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7
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Meker S, Chin H, Sut TN, Cho NJ. Amyloid-β Peptide Triggers Membrane Remodeling in Supported Lipid Bilayers Depending on Their Hydrophobic Thickness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9548-9560. [PMID: 30021071 DOI: 10.1021/acs.langmuir.8b01196] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Amyloid-β (Aβ) peptide has been implicated in Alzheimer's disease, which is a leading cause of death worldwide. The interaction of Aβ peptides with the lipid bilayers of neuronal cells is a critical step in disease pathogenesis. Recent evidence indicates that lipid bilayer thickness influences Aβ membrane-associated aggregation, while understanding how Aβ interacts with lipid bilayers remains elusive. To address this question, we employed supported lipid bilayer (SLB) platforms composed of different-length phosphatidylcholine (PC) lipids (C12:0 DLPC, C18:1 DOPC, C18:1-C16:0 POPC), and characterized the resulting interactions with soluble Aβ monomers. Quartz crystal microbalance-dissipation (QCM-D) experiments identified concentration-dependent Aβ peptide adsorption onto all tested SLBs, which was corroborated by fluorescence recovery after photobleaching (FRAP) experiments indicating that higher Aβ concentrations led to decreased membrane fluidity. These commonalities pointed to strong Aβ peptide-membrane interactions in all cases. Notably, time-lapsed fluorescence microscopy revealed major differences in Aβ-induced membrane morphological responses depending on SLB hydrophobic thickness. For thicker DOPC and POPC SLBs, membrane remodeling involved the formation of elongated tubule and globular structures as a passive means to regulate membrane stress depending on Aβ concentration. In marked contrast, thin DLPC SLBs were not able to accommodate extensive membrane remodeling. Taken together, our findings reveal that membrane thickness influences the membrane morphological response triggered upon Aβ adsorption.
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Affiliation(s)
- Sigalit Meker
- School of Materials Science and Engineering , Nanyang Technological University , 639798 , Singapore
- Centre for Biomimetic Sensor Science , Nanyang Technological University , 637553 , Singapore
| | - Hokyun Chin
- School of Materials Science and Engineering , Nanyang Technological University , 639798 , Singapore
- Centre for Biomimetic Sensor Science , Nanyang Technological University , 637553 , Singapore
| | - Tun Naw Sut
- School of Materials Science and Engineering , Nanyang Technological University , 639798 , Singapore
- Centre for Biomimetic Sensor Science , Nanyang Technological University , 637553 , Singapore
| | - Nam-Joon Cho
- School of Materials Science and Engineering , Nanyang Technological University , 639798 , Singapore
- Centre for Biomimetic Sensor Science , Nanyang Technological University , 637553 , Singapore
- School of Chemical and Biomedical Engineering , Nanyang Technological University , 637459 , Singapore
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8
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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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9
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Zhang X, London E, Raleigh DP. Sterol Structure Strongly Modulates Membrane-Islet Amyloid Polypeptide Interactions. Biochemistry 2018; 57:1868-1879. [PMID: 29373018 DOI: 10.1021/acs.biochem.7b01190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Amyloid formation has been implicated in a wide range of human diseases, and the interaction of amyloidogenic proteins with membranes are believed to be important for many of them. In type-2 diabetes, human islet amyloid polypeptide (IAPP) forms amyloids, which contribute to β-cell death and dysfunction in the disease. IAPP-membrane interactions are potential mechanisms of cytotoxicity. In vitro studies have shown that cholesterol significantly modulates the ability of model membranes to induce IAPP amyloid formation and IAPP-mediated membrane damage. It is not known if this is due to the general effects of cholesterol on membranes or because of specific sterol-IAPP interactions. The effects of replacing cholesterol with eight other sterols/steroids on IAPP binding to model membranes, membrane disruption, and membrane-mediated amyloid formation were examined. The primary effect of the sterols/steroids on the IAPP-membrane interactions was found to reflect their effect upon membrane order as judged by fluorescence anisotropy measurements. Specific IAPP-sterol/steroid interactions have smaller effects. The fraction of vesicles that bind IAPP was inversely correlated with the sterols/steroids' effect on membrane order, as was the extent of IAPP-induced membrane leakage and the time to form amyloids. The correlation between the fraction of vesicles binding IAPP and membrane leakage was particularly tight, suggesting the restriction of IAPP to a subset of vesicles is responsible for incomplete leakage.
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10
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Xing Y, Pilkington EH, Wang M, Nowell CJ, Kakinen A, Sun Y, Wang B, Davis TP, Ding F, Ke PC. Lysophosphatidylcholine modulates the aggregation of human islet amyloid polypeptide. Phys Chem Chem Phys 2018; 19:30627-30635. [PMID: 29115353 DOI: 10.1039/c7cp06670h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Amyloid aggregation of human islet amyloid polypeptide (IAPP) is a hallmark of type 2 diabetes (T2D), a metabolic disease and a global epidemic. Although IAPP is synthesized in pancreatic β-cells, its fibrils and plaques are found in the extracellular space indicating a causative transmembrane process. Numerous biophysical studies have revealed that cell membranes as well as model lipid vesicles promote the aggregation of amyloid-β (associated with Alzheimer's), α-synuclein (associated with Parkinson's) and IAPP, through electrostatic and hydrophobic interactions between the proteins/peptides and lipid membranes. Using a thioflavin T kinetic assay, transmission electron microscopy, circular dichroism spectroscopy, discrete molecular dynamics simulations as well as free energy calculations here we show that micellar lysophosphatidylcholine (LPC), the most abundant lysophospholipid in the blood, inhibited the amyloid aggregation of IAPP through nonspecific interactions while elevating the α-helical peptide secondary structure. This surprising finding suggests a native protective mechanism against IAPP aggregation in vivo.
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Affiliation(s)
- Yanting Xing
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
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11
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Mawhinney MT, Williams TL, Hart JL, Taheri ML, Urbanc B. Elucidation of insulin assembly at acidic and neutral pH: Characterization of low molecular weight oligomers. Proteins 2017; 85:2096-2110. [PMID: 28796342 DOI: 10.1002/prot.25365] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/18/2017] [Accepted: 07/26/2017] [Indexed: 12/13/2022]
Abstract
Deficiency in insulin secretion and function that characterize type 2 diabetes often requires administration of extraneous insulin, leading to injection-site amyloidosis. Insulin aggregation at neutral pH is not well understood. Although oligomer formation is believed to play an important role, insulin oligomers have not been fully characterized yet. Here, we elucidate similarities and differences between in vitro insulin aggregation at acidic and neutral pH for a range of insulin concentrations (2.5-100 μM) by using kinetic thioflavin T fluorescence, circular dichroism, atomic force and electron microscopy imaging. Importantly, we characterize the size distribution of insulin oligomers at different assembly stages by the application of covalent cross-linking and gel electrophoresis. Our results show that at the earliest assembly stage, oligomers comprise up to 40% and 70% of soluble insulin at acidic and neutral pH, respectively. While the highest oligomer order increases with insulin concentration at acidic pH, the opposite tendency is observed at neutral pH, where oligomers up to heptamers are formed in 10 μM insulin. These findings suggest that oligomers may be on- and off-pathway assemblies for insulin at acidic and neutral pH, respectively. Agitation, which is required to induce insulin aggregation at neutral pH, is shown to increase fibril formation rate and fibrillar mass both by an order of magnitude. Insulin incubated under agitated conditions at neutral pH rapidly aggregates into large micrometer-sized aggregates, which may be of physiological relevance and provides insight into injection-site amyloidosis and toxic pulmonary aggregates induced by administration of extraneous insulin.
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Affiliation(s)
| | - Thomas L Williams
- Department of Physics, Drexel University, Philadelphia, PA, USA.,Clarivate Analytics, 1500 Spring Garden Street, Philadelphia, PA, USA
| | - James L Hart
- Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA
| | - Mitra L Taheri
- Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA
| | - Brigita Urbanc
- Department of Physics, Drexel University, Philadelphia, PA, USA.,Faculty of Mathematics and Physics, Jadranska ulica 19, Ljubljana, 1000, Slovenia
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12
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Breydo L, Redington JM, Uversky VN. Effects of Intrinsic and Extrinsic Factors on Aggregation of Physiologically Important Intrinsically Disordered Proteins. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 329:145-185. [PMID: 28109327 DOI: 10.1016/bs.ircmb.2016.08.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Misfolding and aggregation of proteins and peptides play an important role in a number of diseases as well as in many physiological processes. Many of the proteins that misfold and aggregate in vivo are intrinsically disordered. Protein aggregation is a complex multistep process, and aggregates can significantly differ in morphology, structure, stability, cytotoxicity, and self-propagation ability. The aggregation process is influenced by both intrinsic (e.g., mutations and expression levels) and extrinsic (e.g., polypeptide chain truncation, macromolecular crowding, posttranslational modifications, as well as interaction with metal ions, other small molecules, lipid membranes, and chaperons) factors. This review examines the effect of a variety of these factors on aggregation of physiologically important intrinsically disordered proteins.
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Affiliation(s)
- L Breydo
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States.
| | - J M Redington
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - V N Uversky
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States; Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.
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13
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Huang F, Wang Q, Ma X, Wu L, Guo F, Qin G. Valsartan inhibits amylin-induced podocyte damage. Microvasc Res 2016; 106:101-9. [PMID: 27102209 DOI: 10.1016/j.mvr.2016.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 03/19/2016] [Accepted: 04/16/2016] [Indexed: 01/01/2023]
Abstract
Previous studies have described the deposition of amylin in the kidney of patients with type 2 diabetes mellitus (T2DM). These deposits play a critical role in the pathogenesis of diabetic nephropathy (DN), although the mechanism underlying this effect is unknown. Thus, this study was undertaken to investigate whether amylin aggregation stimulates the local angiotensin II type 1 receptor (AT1R) in podocytes, and to examine its role in podocyte apoptosis. Amylin-induced apoptosis was investigated in vitro in differentiated, conditionally immortalized mouse podocytes and in vivo in KM mice. Expression of genes including nephrin, podocin, AT1R and desmin was measured through quantitative real time PCR, western blot and immunohistochemistry. Apoptosis was determined by flow cytometry, while the cellular distribution of podocin and nephrin was investigated by immunofluorescence. The ultra-structure of glomeruli was examined by transmission electron microscopy (TEM). Amylin enhanced apoptosis in a dose-dependent manner in vitro. The peptide also suppressed podocin and nephrin expression, but enhanced that of AT1R and desmin. Both effects were significantly blocked by valsartan, which inhibits angiotensin II type 1 receptor. These findings suggest that amylin activates a local intracellular RAS in podocytes and induces damage and apoptosis.
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Affiliation(s)
- Fengjuan Huang
- Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China; Institute of Clinical Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Qingzhu Wang
- Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Xiaojun Ma
- Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Lina Wu
- Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Feng Guo
- Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Guijun Qin
- Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
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14
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Hoppe T, Minton AP. An equilibrium model for the combined effect of macromolecular crowding and surface adsorption on the formation of linear protein fibrils. Biophys J 2015; 108:957-966. [PMID: 25692600 DOI: 10.1016/j.bpj.2014.12.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/11/2014] [Accepted: 12/17/2014] [Indexed: 12/01/2022] Open
Abstract
The formation of linear protein fibrils has previously been shown to be enhanced by volume exclusion or crowding in the presence of a high concentration of chemically inert protein or polymer, and by adsorption to membrane surfaces. An equilibrium mesoscopic model for the combined effect of both crowding and adsorption upon the fibrillation of a dilute tracer protein is presented. The model exhibits behavior that differs qualitatively from that observed in the presence of crowding or adsorption alone. The model predicts that in a crowded solution, at critical values of the volume fraction of crowder or intrinsic energy of the tracer-wall interaction, the tracer protein will undergo an extremely cooperative transition-approaching a step function-from existence as a slightly self-associated species in solution to existence as a highly self-associated and completely adsorbed species. Criteria for a valid experimental test of these predictions are presented.
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Affiliation(s)
- Travis Hoppe
- Section on Physical Biochemistry, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Allen P Minton
- Section on Physical Biochemistry, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland.
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15
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Uptake of raft components into amyloid β-peptide aggregates and membrane damage. Anal Biochem 2015; 481:18-26. [PMID: 25908557 DOI: 10.1016/j.ab.2015.04.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/13/2015] [Accepted: 04/12/2015] [Indexed: 01/26/2023]
Abstract
Amyloid aggregation and deposition of amyloid β-peptide (Aβ) are pathologic characteristics of Alzheimer's disease (AD). Recent reports have shown that the association of Aβ with membranes containing ganglioside GM1 (GM1) plays a pivotal role in amyloid deposition and the pathogenesis of AD. However, the molecular interactions responsible for membrane damage associated with Aβ deposition are not fully understood. In this study, we microscopically observed amyloid aggregation of Aβ in the presence of lipid vesicles and on a substrate-supported planar membrane containing raft components and GM1. The experimental system enabled us to observe lipid-associated aggregation of Aβ, uptake of the raft components into Aβ aggregates, and relevant membrane damage. The results indicate that uptake of raft components from the membrane into Aβ deposits induces macroscopic heterogeneity of the membrane structure.
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16
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Gao M, Winter R. The Effects of Lipid Membranes, Crowding and Osmolytes on the Aggregation, and Fibrillation Propensity of Human IAPP. J Diabetes Res 2015; 2015:849017. [PMID: 26582333 PMCID: PMC4637101 DOI: 10.1155/2015/849017] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/16/2015] [Indexed: 12/13/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is an age-related and metabolic disease. Its development is hallmarked, among others, by the dysfunction and degeneration of β-cells of the pancreatic islets of Langerhans. The major pathological characteristic thereby is the formation of extracellular amyloid deposits consisting of the islet amyloid polypeptide (IAPP). The process of human IAPP (hIAPP) self-association, and the intermediate structures formed as well as the interaction of hIAPP with membrane systems seem to be, at least to a major extent, responsible for the cytotoxicity. Here we present a summary and comparison of the amyloidogenic propensities of hIAPP in bulk solution and in the presence of various neutral and charged lipid bilayer systems as well as biological membranes. We also discuss the cellular effects of macromolecular crowding and osmolytes on the aggregation pathway of hIAPP. Understanding the influence of different cellular factors on hIAPP aggregation will provide more insight into the onset of T2DM and help to develop novel therapeutic strategies.
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Affiliation(s)
- Mimi Gao
- Physical Chemistry I-Biophysical Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund, Otto-Hahn Street 6, 44227 Dortmund, Germany
| | - Roland Winter
- Physical Chemistry I-Biophysical Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund, Otto-Hahn Street 6, 44227 Dortmund, Germany
- *Roland Winter:
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17
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Tomasello MF, Sinopoli A, Pappalardo G. On the Environmental Factors Affecting the Structural and Cytotoxic Properties of IAPP Peptides. J Diabetes Res 2015; 2015:918573. [PMID: 26582441 PMCID: PMC4637107 DOI: 10.1155/2015/918573] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/05/2015] [Indexed: 12/18/2022] Open
Abstract
Pancreatic islets in type 2 diabetes mellitus (T2DM) patients are characterized by reduced β-cells mass and diffuse extracellular amyloidosis. Amyloid deposition involves the islet amyloid polypeptide (IAPP), a neuropancreatic hormone cosecreted with insulin by β-cells. IAPP is physiologically involved in glucose homeostasis, but it may turn toxic to β-cells owing to its tendency to misfold giving rise to oligomers and fibrils. The process by which the unfolded IAPP starts to self-assemble and the overall factors promoting this conversion are poorly understood. Other open questions are related to the nature of the IAPP toxic species and how exactly β-cells die. Over the last decades, there has been growing consensus about the notion that early molecular assemblies, notably small hIAPP oligomers, are the culprit of β-cells decline. Numerous environmental factors might affect the conformational, aggregation, and cytotoxic properties of IAPP. Herein we review recent progress in the field, focusing on the influences that membranes, pH, and metal ions may have on the conformational conversion and cytotoxicity of full-length IAPP as well as peptide fragments thereof. Current theories proposed for the mechanisms of toxicity will be also summarized together with an outline of the underlying molecular links between IAPP and amyloid beta (Aβ) misfolding.
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Affiliation(s)
| | - Alessandro Sinopoli
- International PhD Program in Translational Biomedicine, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Pappalardo
- CNR Institute of Biostructures and Bioimaging, Via P. Gaifami 18, 95126 Catania, Italy
- *Giuseppe Pappalardo:
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18
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Milardi D, Sciacca MFM, Randazzo L, Raudino A, La Rosa C. The role of calcium, lipid membranes and islet amyloid polypeptide in the onset of type 2 diabetes: innocent bystanders or partners in a crime? Front Endocrinol (Lausanne) 2014; 5:216. [PMID: 25566188 PMCID: PMC4268396 DOI: 10.3389/fendo.2014.00216] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/01/2014] [Indexed: 12/15/2022] Open
Affiliation(s)
- Danilo Milardi
- Istituto CNR di Biostrutture e Bioimmagini-Sezione di Catania, Catania, Italy
| | - Michele F. M. Sciacca
- Dipartimento di Scienze Chimiche Viale Andrea Doria 6, Università Degli Studi di Catania, Catania, Italy
| | - Loredana Randazzo
- Istituto CNR di Biostrutture e Bioimmagini-Sezione di Catania, Catania, Italy
| | - Antonino Raudino
- Dipartimento di Scienze Chimiche Viale Andrea Doria 6, Università Degli Studi di Catania, Catania, Italy
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche Viale Andrea Doria 6, Università Degli Studi di Catania, Catania, Italy
- *Correspondence:
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