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Chen Z, Xiao X, Yang L, Lian C, Xu S, Liu H. Prion-like Aggregation of the Heptapeptide GNNQQNY into Amyloid Nanofiber Is Governed by Configuration Entropy. J Chem Inf Model 2023; 63:6423-6435. [PMID: 37782627 DOI: 10.1021/acs.jcim.3c00370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
A major cause of prion infectivity is the early formation of small, fibril-like aggregates consisting of the heptapeptide GNNQQNY. The prion aggregates exhibit a unique stacking mode in which the hydrophobic tyrosine (Y) is exposed outward, forming a bilayer β-sheet-stacking zipper structure. This stacking mode of the prion peptides, termed "Y-outward" structure for convenience, goes against the common understanding that, for other amyloid-forming peptides, the hydrophobic residues should be hidden within the peptide fibril, referred to as "Y-inward" structure. To explore the extraordinary stacking behaviors of the prion GNNQQNY peptides, two fibril models are constructed in a fashion of "Y-outward" and "Y-inward" stackings and then studied in silico to examine their thermodynamic stabilities and disaggregation pathways. The "Y-inward" structure indeed exhibits stronger thermodynamic stability than the "Y-outward" structure, according to potential energy and stacking energy calculations. To show how the peptide fibrils dissociate, we illustrated two disaggregation pathways. A dihedral-based free energy landscape was then calculated to examine the conformational degrees of freedom of the GNNQQNY chains in the "Y-outward" and "Y-inward" structures. Peptide chains lose more configurational entropy in the "Y-inward" structure than in the "Y-outward" structure, indicating that the prion peptides are prone to aggregate in a fashion of "Y-outward" stacking pattern due to its low conformational constraints. The prion-like aggregation of the GNNQQNY peptides into amyloid fibrils is primarily governed by the configuration entropy.
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Affiliation(s)
- Zhangyang Chen
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Xingqing Xiao
- Department of Chemistry, School of Chemistry and Chemical Engineering, Hainan University, Haikou City, Hainan Province 570228, P. R. China
| | - Li Yang
- Key Laboratory of Green Chemical Process of Ministry of Education, Key Laboratory of Novel Reactor and Green Chemical Technology of Hubei Province, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, P. R. China
| | - Cheng Lian
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Shouhong Xu
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Honglai Liu
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
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Ganekal P, Vastrad B, Kavatagimath S, Vastrad C, Kotrashetti S. Bioinformatics and Next-Generation Data Analysis for Identification of Genes and Molecular Pathways Involved in Subjects with Diabetes and Obesity. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59020309. [PMID: 36837510 PMCID: PMC9967176 DOI: 10.3390/medicina59020309] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/19/2023] [Accepted: 01/29/2023] [Indexed: 02/10/2023]
Abstract
Background and Objectives: A subject with diabetes and obesity is a class of the metabolic disorder. The current investigation aimed to elucidate the potential biomarker and prognostic targets in subjects with diabetes and obesity. Materials and Methods: The next-generation sequencing (NGS) data of GSE132831 was downloaded from Gene Expression Omnibus (GEO) database. Functional enrichment analysis of DEGs was conducted with ToppGene. The protein-protein interactions network, module analysis, target gene-miRNA regulatory network and target gene-TF regulatory network were constructed and analyzed. Furthermore, hub genes were validated by receiver operating characteristic (ROC) analysis. A total of 872 DEGs, including 439 up-regulated genes and 433 down-regulated genes were observed. Results: Second, functional enrichment analysis showed that these DEGs are mainly involved in the axon guidance, neutrophil degranulation, plasma membrane bounded cell projection organization and cell activation. The top ten hub genes (MYH9, FLNA, DCTN1, CLTC, ERBB2, TCF4, VIM, LRRK2, IFI16 and CAV1) could be utilized as potential diagnostic indicators for subjects with diabetes and obesity. The hub genes were validated in subjects with diabetes and obesity. Conclusion: This investigation found effective and reliable molecular biomarkers for diagnosis and prognosis by integrated bioinformatics analysis, suggesting new and key therapeutic targets for subjects with diabetes and obesity.
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Affiliation(s)
- Prashanth Ganekal
- Department of General Medicine, Basaveshwara Medical College, Chitradurga 577501, Karnataka, India
| | - Basavaraj Vastrad
- Department of Pharmaceutical Chemistry, K.L.E. College of Pharmacy, Gadag 582101, Karnataka, India
| | - Satish Kavatagimath
- Department of Pharmacognosy, K.L.E. College of Pharmacy, Belagavi 590010, Karnataka, India
| | - Chanabasayya Vastrad
- Biostatistics and Bioinformatics, Chanabasava Nilaya, Bharthinagar, Dharwad 580001, Karnataka, India
- Correspondence: ; Tel.: +91-9480073398
| | - Shivakumar Kotrashetti
- Biostatistics and Bioinformatics, Chanabasava Nilaya, Bharthinagar, Dharwad 580001, Karnataka, India
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Ldlr-Deficient Mice with an Atherosclerosis-Resistant Background Develop Severe Hyperglycemia and Type 2 Diabetes on a Western-Type Diet. Biomedicines 2022; 10:biomedicines10061429. [PMID: 35740449 PMCID: PMC9220196 DOI: 10.3390/biomedicines10061429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 01/10/2023] Open
Abstract
Apoe-/- and Ldlr-/- mice are two animal models extensively used for atherosclerosis research. We previously reported that Apoe-/- mice on certain genetic backgrounds, including C3H/HeJ (C3H), develop type 2 diabetes when fed a Western diet. We sought to characterize diabetes-related traits in C3H-Ldlr-/- mice through comparing with C3H-Apoe-/- mice. On a chow diet, Ldlr-/- mice had lower plasma total and non-HDL cholesterol levels but higher HDL levels than Apoe-/- mice. Fasting plasma glucose was much lower in Ldlr-/- than Apoe-/- mice (male: 122.5 ± 5.9 vs. 229.4 ± 17.5 mg/dL; female: 144.1 ± 12.4 vs. 232.7 ± 6.4 mg/dL). When fed a Western diet, Ldlr-/- and Apoe-/- mice developed severe hypercholesterolemia and also hyperglycemia with fasting plasma glucose levels exceeding 250 mg/dL. Both knockouts had similar non-HDL cholesterol and triglyceride levels, and their fasting glucose levels were also similar. Male Ldlr-/- mice exhibited greater glucose tolerance and insulin sensitivity compared to their Apoe-/- counterpart. Female mice showed similar glucose tolerance and insulin sensitivity though Ldlr-/- mice had higher non-fasting glucose levels. Male Ldlr-/- and Apoe-/- mice developed moderate obesity on the Western diet, but female mice did not. These results indicate that the Western diet and ensuing hyperlipidemia lead to the development of type 2 diabetes, irrespective of underlying genetic causes.
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Hiller H, Yang C, Beachy DE, Kusmartseva I, Candelario-Jalil E, Posgai AL, Nick HS, Schatz D, Atkinson MA, Wasserfall CH. Altered cellular localisation and expression, together with unconventional protein trafficking, of prion protein, PrP C, in type 1 diabetes. Diabetologia 2021; 64:2279-2291. [PMID: 34274990 PMCID: PMC8715394 DOI: 10.1007/s00125-021-05501-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/17/2021] [Indexed: 12/22/2022]
Abstract
AIMS/HYPOTHESIS Normal cellular prion protein (PrPC) is a conserved mammalian glycoprotein found on the outer plasma membrane leaflet through a glycophosphatidylinositol anchor. Although PrPC is expressed by a wide range of tissues throughout the body, the complete repertoire of its functions has not been fully determined. The misfolded pathogenic isoform PrPSc (the scrapie form of PrP) is a causative agent of neurodegenerative prion diseases. The aim of this study is to evaluate PrPC localisation, expression and trafficking in pancreases from organ donors with and without type 1 diabetes and to infer PrPC function through studies on interacting protein partners. METHODS In order to evaluate localisation and trafficking of PrPC in the human pancreas, 12 non-diabetic, 12 type 1 diabetic and 12 autoantibody-positive organ donor tissue samples were analysed using immunofluorescence analysis. Furthermore, total RNA was isolated from 29 non-diabetic, 29 type 1 diabetic and 24 autoantibody-positive donors to estimate PrPC expression in the human pancreas. Additionally, we performed PrPC-specific immunoblot analysis on total pancreatic protein from non-diabetic and type 1 diabetic organ donors to test whether changes in PrPC mRNA levels leads to a concomitant increase in PrPC protein levels in human pancreases. RESULTS In non-diabetic and type 1 diabetic pancreases (the latter displaying both insulin-positive [INS(+)] and -negative [INS(-)] islets), we found PrPC in islets co-registering with beta cells in all INS(+) islets and, strikingly, unexpected activation of PrPC in alpha cells within diabetic INS(-) islets. We found PrPC localised to the plasma membrane and endoplasmic reticulum (ER) but not the Golgi, defining two cellular pools and an unconventional protein trafficking mechanism bypassing the Golgi. We demonstrate PrPC co-registration with established protein partners, neural cell adhesion molecule 1 (NCAM1) and stress-inducible phosphoprotein 1 (STI1; encoded by STIP1) on the plasma membrane and ER, respectively, linking PrPC function with cyto-protection, signalling, differentiation and morphogenesis. We demonstrate that both PRNP (encoding PrPC) and STIP1 gene expression are dramatically altered in type 1 diabetic and autoantibody-positive pancreases. CONCLUSIONS/INTERPRETATION As the first study to address PrPC expression in non-diabetic and type 1 diabetic human pancreas, we provide new insights for PrPC in the pathogenesis of type 1 diabetes. We evaluated the cell-type specific expression of PrPC in the human pancreas and discovered possible connections with potential interacting proteins that we speculate might address mechanisms relevant to the role of PrPC in the human pancreas.
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Affiliation(s)
- Helmut Hiller
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Changjun Yang
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Dawn E Beachy
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Irina Kusmartseva
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | | | - Amanda L Posgai
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Harry S Nick
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Desmond Schatz
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Mark A Atkinson
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Clive H Wasserfall
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA.
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Schmitt-Ulms G, Mehrabian M, Williams D, Ehsani S. The IDIP framework for assessing protein function and its application to the prion protein. Biol Rev Camb Philos Soc 2021; 96:1907-1932. [PMID: 33960099 DOI: 10.1111/brv.12731] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 04/22/2021] [Accepted: 04/26/2021] [Indexed: 01/06/2023]
Abstract
The quest to determine the function of a protein can represent a profound challenge. Although this task is the mandate of countless research groups, a general framework for how it can be approached is conspicuously lacking. Moreover, even expectations for when the function of a protein can be considered to be 'known' are not well defined. In this review, we begin by introducing concepts pertinent to the challenge of protein function assignments. We then propose a framework for inferring a protein's function from four data categories: 'inheritance', 'distribution', 'interactions' and 'phenotypes' (IDIP). We document that the functions of proteins emerge at the intersection of inferences drawn from these data categories and emphasise the benefit of considering them in an evolutionary context. We then apply this approach to the cellular prion protein (PrPC ), well known for its central role in prion diseases, whose function continues to be considered elusive by many investigators. We document that available data converge on the conclusion that the function of the prion protein is to control a critical post-translational modification of the neural cell adhesion molecule in the context of epithelial-to-mesenchymal transition and related plasticity programmes. Finally, we argue that this proposed function of PrPC has already passed the test of time and is concordant with the IDIP framework in a way that other functions considered for this protein fail to achieve. We anticipate that the IDIP framework and the concepts analysed herein will aid the investigation of other proteins whose primary functional assignments have thus far been intractable.
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Affiliation(s)
- Gerold Schmitt-Ulms
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, M5T 0S8, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | | | - Declan Williams
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, M5T 0S8, Canada
| | - Sepehr Ehsani
- Theoretical and Philosophical Biology, Department of Philosophy, University College London, Bloomsbury, London, WC1E 6BT, U.K.,Ronin Institute for Independent Scholarship, Montclair, NJ, 07043, U.S.A
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Prashanth G, Vastrad B, Tengli A, Vastrad C, Kotturshetti I. Investigation of candidate genes and mechanisms underlying obesity associated type 2 diabetes mellitus using bioinformatics analysis and screening of small drug molecules. BMC Endocr Disord 2021; 21:80. [PMID: 33902539 PMCID: PMC8074411 DOI: 10.1186/s12902-021-00718-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/02/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Obesity associated type 2 diabetes mellitus is a metabolic disorder ; however, the etiology of obesity associated type 2 diabetes mellitus remains largely unknown. There is an urgent need to further broaden the understanding of the molecular mechanism associated in obesity associated type 2 diabetes mellitus. METHODS To screen the differentially expressed genes (DEGs) that might play essential roles in obesity associated type 2 diabetes mellitus, the publicly available expression profiling by high throughput sequencing data (GSE143319) was downloaded and screened for DEGs. Then, Gene Ontology (GO) and REACTOME pathway enrichment analysis were performed. The protein - protein interaction network, miRNA - target genes regulatory network and TF-target gene regulatory network were constructed and analyzed for identification of hub and target genes. The hub genes were validated by receiver operating characteristic (ROC) curve analysis and RT- PCR analysis. Finally, a molecular docking study was performed on over expressed proteins to predict the target small drug molecules. RESULTS A total of 820 DEGs were identified between healthy obese and metabolically unhealthy obese, among 409 up regulated and 411 down regulated genes. The GO enrichment analysis results showed that these DEGs were significantly enriched in ion transmembrane transport, intrinsic component of plasma membrane, transferase activity, transferring phosphorus-containing groups, cell adhesion, integral component of plasma membrane and signaling receptor binding, whereas, the REACTOME pathway enrichment analysis results showed that these DEGs were significantly enriched in integration of energy metabolism and extracellular matrix organization. The hub genes CEBPD, TP73, ESR2, TAB1, MAP 3K5, FN1, UBD, RUNX1, PIK3R2 and TNF, which might play an essential role in obesity associated type 2 diabetes mellitus was further screened. CONCLUSIONS The present study could deepen the understanding of the molecular mechanism of obesity associated type 2 diabetes mellitus, which could be useful in developing therapeutic targets for obesity associated type 2 diabetes mellitus.
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Affiliation(s)
- G Prashanth
- Department of General Medicine, Basaveshwara Medical College, Chitradurga, Karnataka, 577501, India
| | - Basavaraj Vastrad
- Department of Biochemistry, Basaveshwar College of Pharmacy, Gadag, Karnataka, 582103, India
| | - Anandkumar Tengli
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru and JSS Academy of Higher Education & Research, Mysuru, Karnataka, 570015, India
| | - Chanabasayya Vastrad
- Biostatistics and Bioinformatics, Chanabasava Nilaya, Bharthinagar, Dharwad, Karnataka, 580001, India.
| | - Iranna Kotturshetti
- Department of Ayurveda, Rajiv Gandhi Education Society`s Ayurvedic Medical College, Ron, Karnataka, 582209, India
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Martinez-Valbuena I, Valenti-Azcarate R, Amat-Villegas I, Marcilla I, Marti-Andres G, Caballero MC, Riverol M, Tuñon MT, Fraser PE, Luquin MR. Mixed pathologies in pancreatic β cells from subjects with neurodegenerative diseases and their interaction with prion protein. Acta Neuropathol Commun 2021; 9:64. [PMID: 33832546 PMCID: PMC8028740 DOI: 10.1186/s40478-021-01171-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 03/28/2021] [Indexed: 12/22/2022] Open
Abstract
Protein misfolding diseases refer to a variety of disorders that develop as a consequence of the misfolding of proteins in various organs. The etiologies of Parkinson’s and Alzheimer’s disease remain unclear, but it seems that type two diabetes and other prediabetic states could contribute to the appearance of the sporadic forms of these diseases. In addition to amylin deposition, other amyloidogenic proteins implicated in the pathophysiology of neurodegenerative diseases could have important roles in the pathogenesis of this disease. As we have previously demonstrated the presence of α-synuclein deposits in the pancreas of patients with synucleinopathies, as well as tau and Aβ deposits in the pancreatic tissue of Alzheimer’s disease patients, we studied the immunoreactivity of amylin, tau and α-synuclein in the pancreas of 138 subjects with neurodegenerative diseases or type two diabetes and assessed whether the pancreatic β-cells of these subjects present cooccurrence of misfolded proteins. Furthermore, we also assessed the pancreatic expression of prion protein (PrP) in these subjects and its interaction, both in the pancreas and brain, with α-synuclein, tau, Aβ and amylin. Our study shows, for the first time, that along with amylin, pancreatic α-synuclein, Aβ, PrP and tau may contribute together to the complex pathophysiology of type two diabetes and in the appearance of insulin resistance in Alzheimer’s and Parkinson’s disease. Furthermore, we show that the same mixed pathologies that are observed in the brains of patients with neurodegenerative diseases are also present outside the nervous system. Finally, we provide the first histological evidence of an interaction between PrP and Aβ, α-synuclein, amylin or tau in the pancreas and locus coeruleus. These findings will shed more light on the common pathological pathways shared by neurodegenerative diseases and type two diabetes, benefiting the exploration of common therapeutic strategies to prevent or treat these devastating amyloid diseases.
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Zhang Y, Zhang M, Liu Y, Zhang D, Tang Y, Ren B, Zheng J. Dual amyloid cross-seeding reveals steric zipper-facilitated fibrillization and pathological links between protein misfolding diseases. J Mater Chem B 2021; 9:3300-3316. [PMID: 33651875 DOI: 10.1039/d0tb02958k] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Amyloid cross-seeding, as a result of direct interaction and co-aggregation between different disease-causative peptides, is considered as a main mechanism for the spread of the overlapping pathology across different cells and tissues between different protein-misfolding diseases (PMDs). Despite the biomedical significance of amyloid cross-seeding in amyloidogenesis, it remains a great challenge to discover amyloid cross-seeding systems and reveal their cross-seeding structures and mechanisms. Herein, we are the first to report that GNNQQNY - a short fragment from yeast prion protein Sup35 - can cross-seed with both amyloid-β (Aβ, associated with Alzheimer's disease) and human islet amyloid polypeptide (hIAPP, associated with type II diabetes) to form β-structure-rich assemblies and to accelerate amyloid fibrillization. Dry, steric β-zippers, formed by the two β-sheets of different amyloid peptides, provide generally interactive and structural motifs to facilitate amyloid cross-seeding. The presence of different steric β-zippers in a variety of GNNQQNY-Aβ and GNNQQNY-hIAPP assemblies also explains amyloid polymorphism. In addition, alteration of steric zipper formation by single-point mutations of GNNQQNY and interactions of GNNQQNY with different Aβ and hIAPP seeds leads to different amyloid cross-seeding efficiencies, further confirming the existence of cross-seeding barriers. This work offers a better structural-based understanding of amyloid cross-seeding mechanisms linked to different PMDs.
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Affiliation(s)
- Yanxian Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering The University of Akron, Ohio, USA.
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Jones E, Mead S. Genetic risk factors for Creutzfeldt-Jakob disease. Neurobiol Dis 2020; 142:104973. [PMID: 32565065 DOI: 10.1016/j.nbd.2020.104973] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/18/2020] [Accepted: 06/13/2020] [Indexed: 10/24/2022] Open
Abstract
Prion diseases are a group of fatal neurodegenerative disorders of mammals that share a central role for prion protein (PrP, gene PRNP) in their pathogenesis. Prions are infectious agents that account for the observed transmission of prion diseases between humans and animals in certain circumstances. The prion mechanism invokes a misfolded and multimeric assembly of PrP (a prion) that grows by templating of the normal protein and propagates by fission. Aside from the medical and public health notoriety of acquired prion diseases, the conditions have attracted interest as it has been realized that common neurodegenerative disorders share so-called prion-like mechanisms. In this article we will expand on recent evidence for new genetic loci that alter the risk of human prion disease. The most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD), is characterized by the seemingly spontaneous appearance of prions in the brain. Genetic variation within PRNP is associated with all types of prion diseases, in particular, heterozygous genotypes at codons 129 and 219 have long been known to be strong protective factors against sCJD. A large number of rare mutations have been described in PRNP that cause autosomal dominant inherited prion diseases. Two loci recently identified by genome-wide association study increase sCJD risk, including variants in or near to STX6 and GAL3ST1. STX6 encodes syntaxin-6, a component of SNARE complexes with cellular roles that include the fusion of intracellular vesicles with target membranes. GAL3ST1 encodes cerebroside sulfotransferase, the only enzyme that sulfates sphingolipids to make sulfatides, a major lipid component of myelin. We discuss how these roles may modify the pathogenesis of prion diseases and their relevance for other neurodegenerative disorders.
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Affiliation(s)
- Emma Jones
- MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, 33 Cleveland Street, W1W 7FF, United Kingdom
| | - Simon Mead
- MRC Prion Unit at University College London (UCL), UCL Institute of Prion Diseases, 33 Cleveland Street, W1W 7FF, United Kingdom.
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Tian Y, Jennings J, Gong Y, Sang Y. Viral Infections and Interferons in the Development of Obesity. Biomolecules 2019; 9:biom9110726. [PMID: 31726661 PMCID: PMC6920831 DOI: 10.3390/biom9110726] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/08/2019] [Accepted: 11/09/2019] [Indexed: 12/14/2022] Open
Abstract
Obesity is now a prevalent disease worldwide and has a multi-factorial etiology. Several viruses or virus-like agents including members of adenoviridae, herpesviridae, slow virus (prion), and hepatitides, have been associated with obesity; meanwhile obese patients are shown to be more susceptible to viral infections such as during influenza and dengue epidemics. We examined the co-factorial role of viral infections, particularly of the persistent cases, in synergy with high-fat diet in induction of obesity. Antiviral interferons (IFNs), as key immune regulators against viral infections and in autoimmunity, emerge to be a pivotal player in the regulation of adipogenesis. In this review, we examine the recent evidence indicating that gut microbiota uphold intrinsic IFN signaling, which is extensively involved in the regulation of lipid metabolism. However, the prolonged IFN responses during persistent viral infections and obesogenesis comprise reciprocal causality between virus susceptibility and obesity. Furthermore, some IFN subtypes have shown therapeutic potency in their anti-inflammation and anti-obesity activity.
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Prion protein modulates glucose homeostasis by altering intracellular iron. Sci Rep 2018; 8:6556. [PMID: 29700330 PMCID: PMC5919926 DOI: 10.1038/s41598-018-24786-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 03/20/2018] [Indexed: 11/08/2022] Open
Abstract
The prion protein (PrPC), a mainly neuronal protein, is known to modulate glucose homeostasis in mouse models. We explored the underlying mechanism in mouse models and the human pancreatic β-cell line 1.1B4. We report expression of PrPC on mouse pancreatic β-cells, where it promoted uptake of iron through divalent-metal-transporters. Accordingly, pancreatic iron stores in PrP knockout mice (PrP-/-) were significantly lower than wild type (PrP+/+) controls. Silencing of PrPC in 1.1B4 cells resulted in significant depletion of intracellular (IC) iron, and remarkably, upregulation of glucose transporter GLUT2 and insulin. Iron overloading, on the other hand, resulted in downregulation of GLUT2 and insulin in a PrPC-dependent manner. Similar observations were noted in the brain, liver, and neuroretina of iron overloaded PrP+/+ but not PrP-/- mice, indicating PrPC-mediated modulation of insulin and glucose homeostasis through iron. Peripheral challenge with glucose and insulin revealed blunting of the response in iron-overloaded PrP+/+ relative to PrP-/- mice, suggesting that PrPC-mediated modulation of IC iron influences both secretion and sensitivity of peripheral organs to insulin. These observations have implications for Alzheimer's disease and diabetic retinopathy, known complications of type-2-diabetes associated with brain and ocular iron-dyshomeostasis.
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Cheng J, Xue F, Zhang M, Cheng C, Qiao L, Ma J, Sui W, Xu X, Gao C, Hao P, Zhang M, Zhang Y. TRIM31 Deficiency Is Associated with Impaired Glucose Metabolism and Disrupted Gut Microbiota in Mice. Front Physiol 2018; 9:24. [PMID: 29497383 PMCID: PMC5818424 DOI: 10.3389/fphys.2018.00024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 01/09/2018] [Indexed: 12/29/2022] Open
Abstract
Tripartite motif-containing protein 31 (TRIM31), an E3 ubiquitin ligase of the tripartite motif family, plays an important role in the innate immune response. It can reduce the activity of the nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome. However, little information is about glucose metabolic health of TRIM31-deficient mice, and investigations about gut microbiota in TRIM31-deficient mice is limited. Thus, we aimed to compare glucose metabolic parameters, gut microbiota composition and inflammatory cytokine levels between TRIM31-/- and wild-type (WT) mice, and further investigate whether or not certain gut microbiota taxon correlates with specific metabolic parameters and inflammation cytokines in TRIM31-deficient mice. TRIM31-/- mice showed glucose intolerance and insulin resistance, with a significant difference in gut microbiota composition, characterized by increased abundance of Prevotellaceae and Veillonellaceae. TRIM31-/- mice with impaired glucose metabolism was accompanied by elevated serum tumor necrosis factor-α (TNF-α) and interleukin 1β (IL-1β) concentrations, as well as upregulated caecal TNF-α, IL-1β, caspase-1, and NLRP3 expressions. Furthermore, elevated p-IRS-1/IRS-1 protein expression, and decreased Akt Thr308 phosphorylation were observed in TRIM31-/- mice. Prevotellaceae abundance was positively associated with caecal IL-1β mRNA expression, and Veillonellaceae was associated with higher TNF-α mRNA expression and serum insulin concentration. In conclusion, our study is novel in showing that TRIM31 deficiency is associated with impaired glucose metabolism and disrupted gut microbiota in mice. This study contributes to the theoretical foundation on the potential relationship between TRIM31 deficiency and the development of abnormal glucose metabolism.
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Affiliation(s)
- Jing Cheng
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Fei Xue
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Meng Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Cheng Cheng
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Lei Qiao
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Jing Ma
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Wenhai Sui
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Xingli Xu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Chengjiang Gao
- Department of Immunology, Shandong University School of Medicine, Jinan, China
| | - Panpan Hao
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Meng Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
| | - Yun Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Shandong University Qilu Hospital, Jinan, China
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