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Bahramikia S, Shirzadi N, Pirmohammadi N. Investigation of the Effect of Pyrogallol on the Formation of Amylin Amyloid Fibrils as a Strategy for the Treatment of Type 2 Diabetic Patients: A Theoretical and Experimental Study. J Fluoresc 2024; 34:245-251. [PMID: 37195541 DOI: 10.1007/s10895-023-03259-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 05/02/2023] [Indexed: 05/18/2023]
Abstract
In more than 50 to 90% of type 2 diabetic patients, under the influence of various factors, the production of islet amyloid polypeptide or amylin in pancreatic beta cells increases. Spontaneous accumulation of amylin peptide in the form of insoluble amyloid fibrils and soluble oligomers is one of the main causes of beta cell death in diabetic patients. The objective of the present study was to evaluate the effect of pyrogallol, as a phenolic compound, on inhibiting the formation of amylin protein amyloid fibrils. In this study, different techniques such as the thioflavin T (ThT) and 1-Anilino-8-naphthalene sulfonate (ANS) fluorescence intensity and the circular dichroism (CD) spectrum, will be used to investigate the effects of this compound on inhibiting the formation of amyloid fibrils. To investigate the interaction sites of pyrogallol with amylin, docking studies were performed. Our results that pyrogallol in a dose-dependent manner (0.5:1, 1:1, and 5:1, Pyr to Amylin) inhibits the amylin amyloid fibrils formation. Docking analysis revealed that pyrogallol forms hydrogen bonds with valine 17 and asparagine 21. In addition, this compound forms 2 more hydrogen bonds with asparagine 22. This compound also forms hydrophobic bonds with histidine 18. Considering this data and the direct relationship between oxidative stress and the formation of amylin amyloid accumulations in diabetes, the use of compounds with both antioxidant and anti-amyloid properties can be considered an important therapeutic strategy for type 2 diabetes.
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Affiliation(s)
- Seifollah Bahramikia
- Department of Biology, Faculty of Basic Sciences, Lorestan University, Khorramabad, Iran.
| | - Nasrin Shirzadi
- Department of Biology, Faculty of Basic Sciences, Lorestan University, Khorramabad, Iran
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2
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Strong CE, Zhang J, Carrasco M, Kundu S, Boutin M, Vishwasrao HD, Liu J, Medina A, Chen YC, Wilson K, Lee EM, Ferrer M. Functional brain region-specific neural spheroids for modeling neurological diseases and therapeutics screening. Commun Biol 2023; 6:1211. [PMID: 38017066 PMCID: PMC10684574 DOI: 10.1038/s42003-023-05582-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 11/14/2023] [Indexed: 11/30/2023] Open
Abstract
3D spheroids have emerged as powerful drug discovery tools given their high-throughput screening (HTS) compatibility. Here, we describe a method for generating functional neural spheroids by cell-aggregation of differentiated human induced pluripotent stem cell (hiPSC)-derived neurons and astrocytes at cell type compositions mimicking specific regions of the human brain. Recordings of intracellular calcium oscillations were used as functional assays, and the utility of this spheroids system was shown through disease modeling, drug testing, and formation of assembloids to model neurocircuitry. As a proof of concept, we generated spheroids incorporating neurons with Alzheimer's disease-associated alleles, as well as opioid use disorder modeling spheroids induced by chronic treatment of a mu-opioid receptor agonist. We reversed baseline functional deficits in each pilot disease model with clinically approved treatments and showed that assembloid activity can be chemogenetically manipulated. Here, we lay the groundwork for brain region-specific neural spheroids as a robust functional assay platform for HTS studies.
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Affiliation(s)
- Caroline E Strong
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Jiajing Zhang
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Martin Carrasco
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Srikanya Kundu
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Molly Boutin
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Harshad D Vishwasrao
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jiamin Liu
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Angelica Medina
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Yu-Chi Chen
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Kelli Wilson
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Emily M Lee
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| | - Marc Ferrer
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA.
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Smith AA, Moore KBE, Ambs PM, Saraswati AP, Fortin JS. Recent Advances in the Discovery of Therapeutics to Curtail Islet Amyloid Polypeptide Aggregation for Type 2 Diabetes Treatment. Adv Biol (Weinh) 2022; 6:e2101301. [PMID: 35931462 DOI: 10.1002/adbi.202101301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 07/04/2022] [Indexed: 01/28/2023]
Abstract
In humans with type 2 diabetes, at least 70% of patients exhibit islet amyloid plaques formed by misfolding islet amyloid polypeptides (IAPP). The oligomeric conformation and accumulation of the IAPP plaques lead to a panoply of cytotoxic effects on the islet β-cells. Currently, no marketed therapies for the prevention or elimination of these amyloid deposits exist, and therefore significant efforts are required to address this gap. To date, most of the experimental treatments are limited to only in vitro stages of testing. In general, the proposed therapeutics use various targeting strategies, such as binding to the N-terminal region of islet amyloid polypeptide on residues 1-19 or the hydrophobic region of IAPP. Other strategies include targeting the peptide self-assembly through π-stacking. These methods are realized by using several different families of compounds, four of which are highlighted in this review: naturally occurring products, small molecules, organometallic compounds, and nanoparticles. Each of these categories holds immense potential to optimize and develop inhibitor(s) of pancreatic amyloidosis in the near future.
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Affiliation(s)
- Alyssa A Smith
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - Kendall B E Moore
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | | | - Akella Prasanth Saraswati
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - Jessica S Fortin
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
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Sevcuka A, White K, Terry C. Factors That Contribute to hIAPP Amyloidosis in Type 2 Diabetes Mellitus. Life (Basel) 2022; 12:life12040583. [PMID: 35455074 PMCID: PMC9025880 DOI: 10.3390/life12040583] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/01/2022] [Accepted: 04/12/2022] [Indexed: 12/24/2022] Open
Abstract
Cases of Type 2 Diabetes Mellitus (T2DM) are increasing at an alarming rate due to the rise in obesity, sedentary lifestyles, glucose-rich diets and other factors. Numerous studies have increasingly illustrated the pivotal role that human islet amyloid polypeptide (hIAPP) plays in the pathology of T2DM through damage and subsequent loss of pancreatic β-cell mass. HIAPP can misfold and form amyloid fibrils which are preceded by pre-fibrillar oligomers and monomers, all of which have been linked, to a certain extent, to β-cell cytotoxicity through a range of proposed mechanisms. This review provides an up-to-date summary of recent progress in the field, highlighting factors that contribute to hIAPP misfolding and aggregation such as hIAPP protein concentration, cell stress, molecular chaperones, the immune system response and cross-seeding with other amyloidogenic proteins. Understanding the structure of hIAPP and how these factors affect amyloid formation will help us better understand how hIAPP misfolds and aggregates and, importantly, help identify potential therapeutic targets for inhibiting amyloidosis so alternate and more effective treatments for T2DM can be developed.
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Roham PH, Save SN, Sharma S. Human islet amyloid polypeptide: A therapeutic target for the management of type 2 diabetes mellitus. J Pharm Anal 2022; 12:556-569. [PMID: 36105173 PMCID: PMC9463490 DOI: 10.1016/j.jpha.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/21/2022] [Accepted: 04/01/2022] [Indexed: 12/22/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) and other metabolic disorders are often silent and go unnoticed in patients because of the lack of suitable prognostic and diagnostic markers. The current therapeutic regimens available for managing T2DM do not reverse diabetes; instead, they delay the progression of diabetes. Their efficacy (in principle) may be significantly improved if implemented at earlier stages. The misfolding and aggregation of human islet amyloid polypeptide (hIAPP) or amylin has been associated with a gradual decrease in pancreatic β-cell function and mass in patients with T2DM. Hence, hIAPP has been recognized as a therapeutic target for managing T2DM. This review summarizes hIAPP's role in mediating dysfunction and apoptosis in pancreatic β-cells via induction of endoplasmic reticulum stress, oxidative stress, mitochondrial dysfunction, inflammatory cytokine secretion, autophagy blockade, etc. Furthermore, it explores the possibility of using intermediates of the hIAPP aggregation pathway as potential drug targets for T2DM management. Finally, the effects of common antidiabetic molecules and repurposed drugs; other hIAPP mimetics and peptides; small organic molecules and natural compounds; nanoparticles, nanobodies, and quantum dots; metals and metal complexes; and chaperones that have demonstrated potential to inhibit and/or reverse hIAPP aggregation and can, therefore, be further developed for managing T2DM have been discussed. Misfolded species of hIAPP form toxic oligomers in pancreatic β-cells. hIAPP amyloids has been detected in the pancreas of about 90% subjects with T2DM. Inhibitors of hIAPP aggregation can help manage T2DM.
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Tang S, Fang C, Liu Y, Tang L, Xu Y. Anti-obesity and Anti-diabetic Effect of Ursolic Acid against Streptozotocin/High Fat Induced Obese in Diabetic Rats. J Oleo Sci 2022; 71:289-300. [PMID: 35034940 DOI: 10.5650/jos.ess21258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Obesity is occurring due to continue taken high fat diet; this is the fast-growing problem reaching epidemic proportion globally. Ursolic acid altered the abnormal glucose metabolism in diabetic rats. In this experimental protocol, we examine ursolic acid (UA) anti-obesity effect against streptozotocin (STZ) and high-fat diet-induced obesity in rats. Orally administered the ursolic acid (2.5, 5 and 10 mg/kg) dose to the hyperglycemic rats for 8 weeks and estimated the blood glucose level at different time intervals. Biochemical, hepatic, lipid, renal and antioxidant parameters were estimated. Traf-4, Mapk-8, Traf-6 and genes such as Ins-1, ngn-3 and Pdx-1 mRNA expression were estimated using qRT-PCR to scrutinize the molecular mechanism in MAPK downstream JNK cascade and insulin pathway signalling pathways. Ursolic acid significantly (p<0.001) down-regulated the blood glucose level at dose dependent manner. Its also reduced the plasma insulin level, non-essential fatty acid and increased the level of adiponectin as compared to obese control group rats. Ursolic acid treated group rats reduced the level of total cholesterol and triglycerides. Ursolic-acid-treated rats have been shown to decrease oxidative stress in pancreatic tissue by restoring the free radical effect of scavenging, suppress the Traf-6, Mapk-8 and Traf-4 mRNA expression, enhance the expression of Pdx-1, Ins-1 and Ngn-3 and ensure the regeneration of pancreas β cells and therefore pancreas insulin. The current result suggested the anti-obese effect of ursolic acid against high fat diet (HFD) induced obese rats via alteration of insulin and JNK signaling pathway.
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Affiliation(s)
- Shiguo Tang
- Department Endocrinology, Ninth People's Hospital of Chongqing
| | - Chao Fang
- Department Endocrinology, Ninth People's Hospital of Chongqing
| | - Yuting Liu
- Department Endocrinology, Ninth People's Hospital of Chongqing
| | - Lihua Tang
- Department Endocrinology, Ninth People's Hospital of Chongqing
| | - Yuanyi Xu
- Department Endocrinology, Ninth People's Hospital of Chongqing
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Tang Y, Zhang D, Liu Y, Zhang Y, Zhou Y, Chang Y, Zheng B, Xu A, Zheng J. A new strategy to reconcile amyloid cross-seeding and amyloid prevention in a binary system of α-synuclein fragmental peptide and hIAPP. Protein Sci 2022; 31:485-497. [PMID: 34850985 PMCID: PMC8820123 DOI: 10.1002/pro.4247] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 02/03/2023]
Abstract
Amyloid cross-seeding and amyloid inhibition are two different research subjects being studied separately for different pathological purposes, in which amyloid cross-seeding targets to study the co-aggregation of different amyloid proteins and potential molecular links between different neurodegenerative diseases, while amyloid inhibition aims to design different molecules for preventing amyloid aggregation. While both amyloid cross-seeding and amyloid inhibition are critical for better understanding the pathological causes of different neurodegenerative diseases including Parkinson disease (PD) and Type 2 diabetes (T2D), less efforts have been made to reconcile the two phenomena. Herein, we proposed a new preventive strategy to demonstrate (a) the cross-seeding of octapeptide TKEQVTNV from α-synuclein (associated with PD) with hIAPP (associated with T2D) and (b) the cross-seeding-promoted hIAPP fibrillization and cross-seeding-reduced hIAPP toxicity. Collective results confirmed that TKEQVTNV can indeed cross-seed with hIAPP monomers and oligomers, not protofibrils, to form β-structure-rich fibrils and to accelerate hIAPP fibrillization. Moreover, such cross-seeding-induced promotion effect by TKEQVTNV also rescued the pancreatic cells from hIAPP-induced cytotoxicity by increasing cell viability and reducing cell apoptosis simultaneously. This work provides a new angle to discover amyloid fragments and use them as amyloid modulators (inhibitors or promotors) to interfere with amyloid aggregation of other amyloid proteins, as well as sequence/structure basis to explore the amyloid cross-seeding between different amyloid proteins that may help explain a potential molecular talk between different neurodegenerative diseases.
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Affiliation(s)
- Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Dong Zhang
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Yonglan Liu
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Yanxian Zhang
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Yifan Zhou
- Department of Polymer ScienceThe University of AkronAkronOhioUSA
| | - Yung Chang
- R&D Center for Membrane Technology, Department of Chemical EngineeringChung Yuan Christian UniversityTaoyuanTaiwan
| | | | | | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
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Tang Y, Liu Y, Zhang Y, Zhang D, Gong X, Zheng J. Repurposing a Cardiovascular Disease Drug of Cloridarol as hIAPP Inhibitor. ACS Chem Neurosci 2021; 12:1419-1427. [PMID: 33780229 DOI: 10.1021/acschemneuro.1c00091] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Accumulating evidence have shown a strong pathological correlation between cardiovascular disease (CVD) and Type II diabetes (T2D), both of which share many common risk factors (e.g., hyperglycemia, hypertension, hypercoagulability, and dyslipidemia) and mutually contribute to each other. Driven by such strong CVD-T2D correlation and marginal benefits from drug development for T2D, here we proposed to repurpose a CVD drug of cloridarol as human islet amyloid peptide (hIAPP) inhibitor against its abnormal misfolding and aggregation, which is considered as a common and critical pathological event in T2D. To this end, we investigated the inhibition activity of cloridarol on the aggregation and toxicity of hIAPP1-37 using combined experimental and computational approaches. Collective experimental data from ThT, AFM, and CD demonstrated the inhibition ability of cloridarol to prevent hIAPP aggregation from its monomeric and oligomeric states, leading to the overall reduction of hIAPP fibrils up to 57% at optimal conditions. MTT and LDH cell assays also showed that cloridarol can also effectively increase cell viability by 15% and decrease cell apoptosis by 28%, confirming its protection of islet β-cells from hIAPP-induced cell toxicity. Furthermore, comparative molecular dynamics simulations revealed that cloridarol was preferentially bound to the C-terminal β-sheet region of hIAPP oligomers through a combination of hydrophobic interactions, π-π stacking, and hydrogen bonding. Such multiple site bindings allowed cloridarol to disturb hIAPP structures, reduce β-sheet content, and block the lateral association pathway of hIAPP aggregates, thus explaining experimental findings. Different from other single-target hIAPP inhibitors, cloridarol is unique in that it works as both a CVD drug and hIAPP inhibitor, which can be used as a viable structural template (especially for benzofuran) for the further development of cloridarol-based or benzofuran-based inhibitors of amyloid proteins.
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Affiliation(s)
- Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion Engineering The University of Akron, Ohio 44325, United States
| | - Yonglan Liu
- Department of Chemical, Biomolecular, and Corrosion Engineering The University of Akron, Ohio 44325, United States
| | | | | | - Xiong Gong
- Department of Polymer Engineering The University of Akron, Ohio 44325, United States
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering The University of Akron, Ohio 44325, United States
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Tang Y, Zhang D, Zhang Y, Liu Y, Gong X, Chang Y, Ren B, Zheng J. Introduction and Fundamentals of Human Islet Amyloid Polypeptide Inhibitors. ACS APPLIED BIO MATERIALS 2020; 3:8286-8308. [DOI: 10.1021/acsabm.0c01234] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325-3906, United States
| | - Dong Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325-3906, United States
| | - Yanxian Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325-3906, United States
| | - Yonglan Liu
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325-3906, United States
| | - Xiong Gong
- Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325-0301, United States
| | - Yung Chang
- Department of Chemical Engineering, R&D Center for Membrane Technology, Chung Yuan Christian University, Taoyuan 320, Taiwan
| | - Baiping Ren
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325-3906, United States
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325-3906, United States
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Effect of Caesalpinia bonduc Polyphenol Extract on Alloxan-Induced Diabetic Rats in Attenuating Hyperglycemia by Upregulating Insulin Secretion and Inhibiting JNK Signaling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:9020219. [PMID: 32256963 PMCID: PMC7103044 DOI: 10.1155/2020/9020219] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 02/29/2020] [Accepted: 03/02/2020] [Indexed: 12/12/2022]
Abstract
Caesalpinia bonduc has been used in herbal medicines for the treatment of a wide range of diseases from decades. The present study has explored the remedial potential and underlying mechanism of polyphenol extract of Caesalpinia bonduc in alloxanized diabetic rats. HPLC/MS analysis confirmed the presence of phenolics in considerable concentrations in Caesalpinia bonduc extract. Administration of different doses (250 and 500 mg/kg) of CPP extract to hyperglycemic rats for 8 weeks restored blood and serum glucose, insulin, glycosylated hemoglobin, leptin, amylin, and carbohydrate metabolizing enzymes level towards normal compared to alloxanized diabetic group. The effect of CPP extract on various genes such as Pdx-1, Ins-1, ngn-3, GLUT-4, and IRS-1 in insulin signaling pathway and Traf-4, Traf-6, and Mapk-8 in MAPK downstream JNK cascade was examined through qRT-PCR to access the core molecular mechanism involved in CPP-induced recovery of diabetes. Results have revealed that CPP extract reduced oxidative stress in pancreatic β cells by restoring free radical scavenging potential, reducing the mRNA expression of Mapk-8, Traf-4, and Traf-6, and increasing the Pdx-1, Ins-1, ngn-3, GLUT-4, and IRS-1 expression ensuing regeneration of β cells and subsequent insulin release from pancreas. The results obtained in this study recommend that CPP extract may be a promising therapeutic restorative agent in the treatment of diabetes mellitus.
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Bolarinwa O, Li C, Khadka N, Li Q, Wang Y, Pan J, Cai J. γ-AApeptides-based Small Molecule Ligands That Disaggregate Human Islet Amyloid Polypeptide. Sci Rep 2020; 10:95. [PMID: 31919432 PMCID: PMC6952368 DOI: 10.1038/s41598-019-56500-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 11/26/2019] [Indexed: 01/21/2023] Open
Abstract
The abnormal folding and aggregation of functional proteins into amyloid is a typical feature of many age-related diseases, including Type II diabetes. Growing evidence has revealed that the prevention of aggregate formation in culprit proteins could retard the progression of amyloid diseases. Human Amylin, also known as human islet amyloid polypeptide (hIAPP), is the major factor for categorizing Type II diabetes as an amyloid disease. Specifically, hIAPP has a great aggregation potential, which always results in a lethal situation for the pancreas. Many peptide inhibitors have been constructed from the various segments of the full-length hIAPP peptide; however, only a few have their origin from the screening of combinatorial peptidomimetic library. In this study, based on HW-155, which was previously discovered from a one-bead-one compound (OBOC) library to inhibit Aβ40 aggregation, we investigated eight (8) analogues and evaluated their amyloid-prevention capabilities for inhibiting fibrillization of hIAPP. Characterization studies revealed that all analogues of HW-155, as well as HW-155, were effective inhibitors of the fibril formation by hIAPP.
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Affiliation(s)
- Olapeju Bolarinwa
- Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida, 33620, United States
| | - Chunpu Li
- Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida, 33620, United States
- Department of Medical Oncology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, P. R. China
| | - Nawal Khadka
- Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida, 33620, United States
| | - Qi Li
- Department of Medical Oncology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, P. R. China
| | - Yan Wang
- Department of Medical Oncology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, P. R. China
| | - Jianjun Pan
- Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida, 33620, United States.
| | - Jianfeng Cai
- Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida, 33620, United States.
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Kumar AP, Lee S, Lukman S. Computational and Experimental Approaches to Design Inhibitors of Amylin Aggregation. Curr Drug Targets 2019; 20:1680-1694. [DOI: 10.2174/1389450120666190719164316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 01/21/2023]
Abstract
Amylin is a neuroendocrine peptide hormone secreted by pancreatic ß-cells; however,
amylin is toxic to ß-cells when it is aggregated in type 2 diabetes mellitus (T2DM). It is important to
understand amylin’s structures and aggregation mechanism for the discovery and design of effective
drugs to inhibit amylin aggregation. In this review, we investigated experimental and computational
studies on amylin structures and inhibitors. Our review provides some novel insights into amylin, particularly
for the design of its aggregation inhibitors to treat T2DM. We detailed the potential inhibitors
that have been studied hitherto and highlighted the neglected need to consider different amylin attributes
that depend on the presence/absence of physiologically relevant conditions, such as membranes.
These conditions and the experimental methods can greatly influence the results of studies on amylininhibitor
complexes. Text-mining over 3,000 amylin-related PubMed abstracts suggests the combined
therapeutic potential of amylin with leptin and glucagon-like peptide-1, which are two key hormones
in obesity. The results also suggest that targeting amylin aggregation can contribute to therapeutic efforts
for Alzheimer’s disease (AD). Therefore, we have also reviewed the role of amylin in other conditions
including obesity and AD. Finally, we provided insights for designing inhibitors of different
types (small molecules, proteins, peptides/mimetics, metal ions) to inhibit amylin aggregation.
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Affiliation(s)
- Ammu Prasanna Kumar
- Department of Chemistry, College of Arts and Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Sungmun Lee
- Department of Biomedical Engineering and Healthcare Engineering Innovation Center, College of Engineering, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Suryani Lukman
- Department of Chemistry, College of Arts and Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
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13
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Synthesis and identification of novel pyridazinylpyrazolone based diazo compounds as inhibitors of human islet amyloid polypeptide aggregation. Bioorg Chem 2019; 84:339-346. [DOI: 10.1016/j.bioorg.2018.11.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 11/17/2018] [Accepted: 11/24/2018] [Indexed: 02/06/2023]
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14
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Influence of methionine–ruthenium complex on the fibril formation of human islet amyloid polypeptide. J Biol Inorg Chem 2019; 24:179-189. [DOI: 10.1007/s00775-019-01637-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/14/2019] [Indexed: 02/07/2023]
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Kanubaddi KR, Yang SH, Wu LW, Lee CH, Weng CF. Nanoparticle-conjugated nutraceuticals exert prospectively palliative of amyloid aggregation. Int J Nanomedicine 2018; 13:8473-8485. [PMID: 30587972 PMCID: PMC6294069 DOI: 10.2147/ijn.s179484] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD), an age-related neurodegenerative disease, the most common causes of dementia is a multifactorial pathology categorized by a complex etiology. Numerous nutraceuticals have been clinically evaluated, but some of the trials failed. However, natural compounds have some limitations due to their poor bioavailability, ineffective capability to cross the blood-brain barrier, or less therapeutic effects on AD. To overcome these disadvantages, nanoparticle-conjugated natural products could promote the bioavailability and enhance the therapeutic efficacy of AD when compared with a naked drug. This application generates and implements new prospect for drug discovery in neurodegenerative diseases. In this article, we confer AD pathology, review natural products in clinical trials, and ascertain the importance of nanomedicine coupled with natural compounds for AD.
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Affiliation(s)
- Kiran Reddy Kanubaddi
- Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan,
| | - Shin-Han Yang
- Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan,
| | - Li-Wei Wu
- Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan,
| | - Chia-Hung Lee
- Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan,
| | - Ching-Feng Weng
- Department of Life Science and Institute of Biotechnology, National Dong Hwa University, Hualien 97401, Taiwan,
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16
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Azzam SK, Jang H, Choi MC, Alsafar H, Lukman S, Lee S. Inhibition of Human Amylin Aggregation and Cellular Toxicity by Lipoic Acid and Ascorbic Acid. Mol Pharm 2018; 15:2098-2106. [PMID: 29709194 DOI: 10.1021/acs.molpharmaceut.7b01009] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
More than 30 human degenerative diseases result from protein aggregation such as Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM). Islet amyloid deposits, a hallmark in T2DM, are found in pancreatic islets of more than 90% of T2DM patients. An association between amylin aggregation and reduction in β-cell mass was also established by post-mortem studies. A strategy in preventing protein aggregation-related disorders is to inhibit the protein aggregation and associated toxicity. In this study, we demonstrated that two inhibitors, lipoic acid and ascorbic acid, significantly inhibited amylin aggregation. Compared to amylin (15 μM) as 100%, lipoic acid and ascorbic acid reduced amylin fibril formation to 42.1 ± 17.2% and 42.9 ± 12.8%, respectively, which is confirmed by fluorescence and TEM images. In cell viability tests, both inhibitors protected RIN-m5f β-cells from the toxicity of amylin aggregates. At 10:1 molar ratio of lipoic acid to amylin, lipoic acid with amylin increased the cell viability to 70.3%, whereas only 42.8% RIN-m5f β-cells survived in amylin aggregates. For ascorbic acid, an equimolar ratio achieved the highest cell viability of 63.3% as compared to 42.8% with amylin aggregates only. Docking results showed that lipoic acid and ascorbic acid physically interact with amylin amyloidogenic region (residues Ser20-Ser29) via hydrophobic interactions; hence reducing aggregation levels. Therefore, lipoic acid and ascorbic acid prevented amylin aggregation via hydrophobic interactions, which resulted in the prevention of cell toxicity in vitro.
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Affiliation(s)
- Sarah Kassem Azzam
- Department of Biomedical Engineering , Khalifa University of Science and Technology , P.O. Box 127788, Abu Dhabi , United Arab Emirates
| | - Hyunwoo Jang
- Department of Bio and Brain Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , South Korea
| | - Myung Chul Choi
- Department of Bio and Brain Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , South Korea
| | - Habiba Alsafar
- Department of Biomedical Engineering , Khalifa University of Science and Technology , P.O. Box 127788, Abu Dhabi , United Arab Emirates.,Khalifa University's Center for Biotechnology , PO Box 127788, Abu Dhabi , United Arab Emirates
| | - Suryani Lukman
- Department of Chemistry, College of Arts and Science , Khalifa University of Science and Technology , P.O. Box 127788, Abu Dhabi , United Arab Emirates
| | - Sungmun Lee
- Department of Biomedical Engineering , Khalifa University of Science and Technology , P.O. Box 127788, Abu Dhabi , United Arab Emirates
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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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18
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Yousaf M, Huang H, Li P, Wang C, Yang Y. Fluorine Functionalized Graphene Quantum Dots as Inhibitor against hIAPP Amyloid Aggregation. ACS Chem Neurosci 2017; 8:1368-1377. [PMID: 28230965 DOI: 10.1021/acschemneuro.7b00015] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Fibrillar deposits of the human islet amyloid polypeptide (hIAPP) are considered as a root of Type II diabetes mellitus. Fluorinated graphene quantum dots (FGQDs) are new carbon nanomaterials with unique physicochemical properties containing highly electronegative F atoms. Herein we report a single step synthesis method of FGQDs with an inhibitory effect on aggregation and cytotoxicity of hIAPP in vitro. Highly fluorescent and water dispersible FGQDs, less than 3 nm in size, were synthesized by the microwave-assisted hydrothermal method. Efficient inhibition capability of FGQDs to amyloid aggregation was demonstrated. The morphologies of hIAPP aggregates were observed to change from the entangled long fibrils to short thin fibrils and amorphous aggregates in the presence of FGQDs. In thioflavin T fluorescence analysis, inhibited aggregation with prolonged lag time and reduced fluorescence intensity at equilibrium were observed when hIAPP was incubated together with FGQDs. Circular dichroism spectrum results reveal that FGQDs could inhibit conformational transition of the peptide from native structure to β-sheets. FGQDs could also rescue the cytotoxicity of INS-1 cells induced by hIAPP in a dose dependent manner. This study could be beneficial for design and preparation of inhibitors for amyloids, which is important for prevention and treatment of amyloidosis.
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Affiliation(s)
- Maryam Yousaf
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- University of Chinese Academy of Sciences , 19 A Yuquan Rd, Shijingshan District, Beijing, P. R. China 100049
| | - Huan Huang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Ping Li
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Chen Wang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- University of Chinese Academy of Sciences , 19 A Yuquan Rd, Shijingshan District, Beijing, P. R. China 100049
| | - Yanlian Yang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- University of Chinese Academy of Sciences , 19 A Yuquan Rd, Shijingshan District, Beijing, P. R. China 100049
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Nurdiana S, Goh YM, Ahmad H, Dom SM, Syimal’ain Azmi N, Noor Mohamad Zin NS, Ebrahimi M. Changes in pancreatic histology, insulin secretion and oxidative status in diabetic rats following treatment with Ficus deltoidea and vitexin. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 17:290. [PMID: 28576138 PMCID: PMC5457635 DOI: 10.1186/s12906-017-1762-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/28/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND The potential application of Ficus deltoidea and vitexin for the management of symptomatologies associated with diabetes mellitus (DM) has gained much attention. However, less firm evidence comes from data to augment our understanding of the role of F. deltoidea and vitexin in protecting pancreatic β-cells. The aim of this study was to assess histological and oxidative stress changes in the pancreas of streptozotocin (STZ)-induced diabetic rats following F. deltoidea extract and vitexin treatment. METHODS F. deltoidea and vitexin was administrated orally to six-weeks STZ-induced diabetic rats over 8 weeks period. The glucose and insulin tolerances were assessed by intraperitoneal glucose (2 g/kg) tolerance test (IPGTT) and intraperitoneal insulin (0.65 U/kg) tolerance test (IPITT), respectively. Subsequently, insulin resistance was assessed by homeostasis assessment model of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI) and the insulin/triglyceride-derived McAuley index. The histological changes in the pancreas were then observed by hematoxylin-eosin (H&E) staining. Further, the pattern of fatty acid composition and infrared (IR) spectra of the serum and pancreas were monitored by gas chromatography (GC) method and Fourier Transform Infrared (FT-IR) spectroscopy. RESULTS F. deltoidea and vitexin increased pancreatic antioxidant enzymes and promoted islet regeneration. However, a significant increase in insulin secretion was observed only in rats treated with F. deltoidea. More importantly, reduction of fasting blood glucose is consistent with reduced FT-IR peaks at 1200-1000 cm-1. CONCLUSIONS These results accentuate that F. deltoidea and vitexin could be a potential agent to attenuate pancreatic oxidative damage and advocate their therapeutic potential for treating DM.
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Zhou S, Wang Q, Ren M, Zhang A, Liu H, Yao X. Molecular dynamics simulation on the inhibition mechanism of peptide-based inhibitor of islet amyloid polypeptide (IAPP) to islet amyloid polypeptide (IAPP22-28) oligomers. Chem Biol Drug Des 2017; 90:31-39. [DOI: 10.1111/cbdd.12924] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/18/2016] [Accepted: 11/27/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Shuangyan Zhou
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry; Lanzhou University; Lanzhou China
- School of Pharmacy; Lanzhou University; Lanzhou China
| | - Qianqian Wang
- State Key Laboratory of Quality Research in Chinese Medicine; Macau Institute for Applied Research in Medicine and Health; Macau University of Science and Technology; Taipa Macau China
| | - Mengdan Ren
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry; Lanzhou University; Lanzhou China
| | - Ai Zhang
- School of Pharmacy; Lanzhou University; Lanzhou China
| | - Huanxiang Liu
- School of Pharmacy; Lanzhou University; Lanzhou China
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry; Lanzhou University; Lanzhou China
- State Key Laboratory of Quality Research in Chinese Medicine; Macau Institute for Applied Research in Medicine and Health; Macau University of Science and Technology; Taipa Macau China
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21
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Purushothaman S, Nair RR. Mitoprotective antioxidant EUK-134 stimulates fatty acid oxidation and prevents hypertrophy in H9C2 cells. Mol Cell Biochem 2016; 420:185-94. [PMID: 27514538 DOI: 10.1007/s11010-016-2788-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 08/05/2016] [Indexed: 11/29/2022]
Abstract
Oxidative stress is an important contributory factor for the development of cardiovascular diseases like hypertension-induced hypertrophy. Mitochondrion is the major source of reactive oxygen species. Hence, protecting mitochondria from oxidative damage can be an effective therapeutic strategy for the prevention of hypertensive heart disease. Conventional antioxidants are not likely to be cardioprotective, as they cannot protect mitochondria from oxidative damage. EUK-134 is a salen-manganese complex with superoxide dismutase and catalase activity. The possible role of EUK-134, a mitoprotective antioxidant, in the prevention of hypertrophy of H9C2 cells was examined. The cells were stimulated with phenylephrine (50 μM), and hypertrophy was assessed based on cell volume and expression of brain natriuretic peptide and calcineurin. Enhanced myocardial lipid peroxidation and protein carbonyl content, accompanied by nuclear factor-kappa B gene expression, confirmed the presence of oxidative stress in hypertrophic cells. Metabolic shift was evident from reduction in the expression of medium-chain acyl-CoA dehydrogenase. Mitochondrial oxidative stress was confirmed by the reduced expression of mitochondria-specific antioxidant peroxiredoxin-3 and enhanced mitochondrial superoxide production. Compromised mitochondrial function was apparent from reduced mitochondrial membrane potential. Pretreatment with EUK-134 (10 μM) was effective in the prevention of hypertrophic changes in H9C2 cells, reduction of oxidative stress, and prevention of metabolic shift. EUK-134 treatment improved the oxidative status of mitochondria and reversed hypertrophy-induced reduction of mitochondrial membrane potential. Supplementation with EUK-134 is therefore identified as a novel approach to attenuate cardiac hypertrophy and lends scope for the development of EUK-134 as a therapeutic agent in the management of human cardiovascular disease.
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Affiliation(s)
- Sreeja Purushothaman
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, India
| | - R Renuka Nair
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, India.
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22
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Chen CH, Yao T, Zhang Q, He YM, Xu LH, Zheng M, Zhou GR, Zhang Y, Yang HJ, Zhou P. Influence of trehalose on human islet amyloid polypeptide fibrillation and aggregation. RSC Adv 2016. [DOI: 10.1039/c5ra27689f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A lower dose of trehalose inhibits or delays, while higher dose of trehalose promotes the hIAPP fibrillation and aggregation.
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23
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Fortin JS, Benoit-Biancamano MO. In Vitro Evaluation of Hypoglycemic Agents to Target Human Islet Amyloid Polypeptide: A Key Protein Involved in Amyloid Deposition and Beta-Cell Loss. Can J Diabetes 2015; 39:373-82. [DOI: 10.1016/j.jcjd.2015.01.291] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 01/09/2015] [Accepted: 01/28/2015] [Indexed: 11/26/2022]
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Abstract
AbstractAbnormal protein folding and self-assembly causes over 30 cureless human diseases for which no disease-modifying therapies are available. The common side to all these diseases is formation of aberrant toxic protein oligomers and amyloid fibrils. Both types of assemblies are drug targets, yet each presents major challenges to drug design, discovery, and development. In this review, we focus on two small molecules that inhibit formation of toxic amyloid protein assemblies — the green-tea derivative (−)-epigallocatechin-3-gallate (EGCG), which was identified through a combination of epidemiologic data and a compound library screen, and the molecular tweezer CLR01, whose inhibitory activity was discovered in our group based on rational reasoning, and subsequently confirmed experimentally. Both compounds act in a manner that is not specific to one particular protein and thus are useful against a multitude of amyloidogenic proteins, yet they act via distinct putative mechanisms. CLR01 disrupts protein aggregation through specific binding to lysine residues, whereas the mechanisms underlying the activity of EGCG are only recently beginning to unveil. We discuss current in vitro and, where available, in vivo literature related to EGCG and CLR01’s effects on amyloid β-protein, α-synuclein, transthyretin, islet amyloid polypeptide, and calcitonin. We also describe the toxicity, pharmacokinetics, and mechanism of action of each compound.
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