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Proteolytic cleavage of the TGFβ co-receptor CD109 changes its conformation, resulting in protease inhibition via activation of its thiol ester, and dissociation from the cell membrane. FEBS J 2024. [PMID: 38587194 DOI: 10.1111/febs.17128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/14/2024] [Accepted: 03/18/2024] [Indexed: 04/09/2024]
Abstract
The glycosylphosphatidylinositol (GPI)-anchored protein cluster of differentiation 109 (CD109) is expressed on many human cell types and modulates the transforming growth factor β (TGF-β) signaling network. CD109 belongs to the alpha-macroglobulin family of proteins, known for their protease-triggered conformational changes. However, the effect of proteolysis on CD109 and its conformation are unknown. Here, we investigated the interactions of CD109 with proteases. We found that a diverse selection of proteases cleaved peptide bonds within the predicted bait region of CD109, inducing a conformational change that activated the thiol ester of CD109. We show CD109 was able to conjugate proteases with this thiol ester and decrease their activity toward protein substrates, demonstrating that CD109 is a protease inhibitor. We additionally found that CD109 has a unique mechanism whereby its GPI-anchored macroglobulin 8 (MG8) domain dissociates during its conformational change, allowing proteases to release CD109 from the cell surface by a precise mechanism and not unspecific shedding. We conclude that proteolysis of the CD109 bait region affects both its structure and location, and that interactions between CD109 and proteases may be important to understanding its functions, for example, as a TGF-β co-receptor.
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Periostin C-Terminal Is Intrinsically Disordered and Interacts with 143 Proteins in an In Vitro Epidermal Model of Atopic Dermatitis. Biochemistry 2023; 62:2803-2815. [PMID: 37704583 PMCID: PMC10552548 DOI: 10.1021/acs.biochem.3c00176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 07/18/2023] [Indexed: 09/15/2023]
Abstract
Human periostin is a 78-91 kDa matricellular protein implicated in extracellular matrix remodeling, tumor development, metastasis, and inflammatory diseases like atopic dermatitis, psoriasis, and asthma. The protein consists of six domains, including an N-terminal Cys-rich CROPT domain, four fasciclin-1 domains, and a C-terminal domain. The exons encoding the C-terminal domain may be alternatively spliced by shuffling four exons, generating ten variants of unknown function. Here, we investigate the structure and interactome of the full-length variant of the C-terminal domain with no exons spliced out. The structural analysis showed that the C-terminal domain lacked a tertiary structure and was intrinsically disordered. In addition, we show that the motif responsible for heparin-binding is in the conserved very C-terminal part of periostin. Pull-down confirmed three known interaction partners and identified an additional 140 proteins, among which nine previously have been implicated in atopic dermatitis. Based on our findings, we suggest that the C-terminal domain of periostin facilitates interactions between connective tissue components in concert with the four fasciclin domains.
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The conformational change of the protease inhibitor α 2-macroglobulin is triggered by the retraction of the cleaved bait region from a central channel. J Biol Chem 2022; 298:102230. [PMID: 35787371 PMCID: PMC9352918 DOI: 10.1016/j.jbc.2022.102230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/24/2022] [Accepted: 06/26/2022] [Indexed: 11/04/2022] Open
Abstract
The protease inhibitor α2-macroglobulin (A2M) is a member of the ancient α2-macroglobulin superfamily (A2MF), which also includes structurally related proteins, such as complement factor C3. A2M and other A2MF proteins undergo an extensive conformational change upon cleavage of their bait region by proteases. However, the mechanism whereby cleavage triggers the change has not yet been determined. We have previously shown that A2M remains functional after completely replacing its bait region with glycine and serine residues. Here, we use this tabula rasa bait region to investigate several hypotheses for the triggering mechanism. When tabula rasa bait regions containing disulfide loops were elongated by reducing the disulfides, we found that A2M remained in its native conformation. In addition, cleavage within a disulfide loop did not trigger the conformational change until after the disulfide was reduced, indicating that the introduction of discontinuity into the bait region is essential to the trigger. Previously, A2MF structures have shown that the C-terminal end of the bait region (a.k.a. the N-terminal region of the truncated α chain) threads through a central channel in native A2MF proteins. Bait region cleavage abolishes this plug-in-channel arrangement, as the bait region retracts from the channel and the channel itself collapses. We found that mutagenesis of conserved plug-in-channel residues disrupted the formation of native A2M. These results provide experimental evidence for a structural hypothesis in which retraction of the bait region from this channel following cleavage and the channel’s subsequent collapse triggers the conformational change of A2M and other A2MF proteins.
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Cryo-EM structures of human A2ML1 elucidate the protease-inhibitory mechanism of the A2M family. Nat Commun 2022; 13:3033. [PMID: 35641520 PMCID: PMC9156758 DOI: 10.1038/s41467-022-30758-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 05/12/2022] [Indexed: 12/26/2022] Open
Abstract
A2ML1 is a monomeric protease inhibitor belonging to the A2M superfamily of protease inhibitors and complement factors. Here, we investigate the protease-inhibitory mechanism of human A2ML1 and determine the structures of its native and protease-cleaved conformations. The functional inhibitory unit of A2ML1 is a monomer that depends on covalent binding of the protease (mediated by A2ML1’s thioester) to achieve inhibition. In contrast to the A2M tetramer which traps proteases in two internal chambers formed by four subunits, in protease-cleaved monomeric A2ML1 disordered regions surround the trapped protease and may prevent substrate access. In native A2ML1, the bait region is threaded through a hydrophobic channel, suggesting that disruption of this arrangement by bait region cleavage triggers the extensive conformational changes that result in protease inhibition. Structural comparisons with complement C3/C4 suggest that the A2M superfamily of proteins share this mechanism for the triggering of conformational change occurring upon proteolytic activation. A2ML1 is a human protease inhibitor belonging to the A2M protein family. In this study, the authors determine structures of A2ML1 before and after protease inhibition and investigate its mechanism of action.
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Development of selective protease inhibitors via engineering of the bait region of human α 2-macroglobulin. J Biol Chem 2021; 297:100879. [PMID: 34139236 PMCID: PMC8267569 DOI: 10.1016/j.jbc.2021.100879] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/02/2021] [Accepted: 06/13/2021] [Indexed: 01/15/2023] Open
Abstract
Human α2-macroglobulin (A2M) is an abundant protease inhibitor in plasma, which regulates many proteolytic processes and is involved in innate immunity. A2M’s unique protease-trapping mechanism of inhibition is initiated when a protease cleaves within the exposed and highly susceptible “bait region.” As the wild-type bait region is permissive to cleavage by most human proteases, A2M is accordingly a broad-spectrum protease inhibitor. In this study, we extensively modified the bait region in order to identify any potential functionally important elements in the bait region sequence and to engineer A2M proteins with restrictive bait regions, which more selectively inhibit a target protease. A2M in which the bait region was entirely replaced by glycine-serine repeats remained fully functional and was not cleaved by any tested protease. Therefore, this bait region was designated as the “tabula rasa” bait region and used as the starting point for further bait region engineering. Cleavage of the tabula rasa bait region by specific proteases was conveyed by the insertion of appropriate substrate sequences, e.g., basic residues for trypsin. Screening and optimization of tabula rasa bait regions incorporating matrix metalloprotease 2 (MMP2) substrate sequences produced an A2M that was specifically cleaved by MMPs and inhibited MMP2 cleavage activity as efficiently as wild-type A2M. We propose that this approach can be used to develop A2M-based protease inhibitors, which selectively inhibit target proteases, which might be applied toward the clinical inhibition of dysregulated proteolysis as occurs in arthritis and many types of cancer.
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Correction: α2-Macroglobulin-like protein 1 can conjugate and inhibit proteases through their hydroxyl groups, because of an enhanced reactivity of its thiol ester. J Biol Chem 2021; 296:100208. [PMID: 33837737 PMCID: PMC7948756 DOI: 10.1016/j.jbc.2020.100208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Substituting the Thiol Ester of Human A2M or C3 with a Disulfide Produces Native Proteins with Altered Proteolysis-Induced Conformational Changes. Biochemistry 2020; 59:4799-4809. [DOI: 10.1021/acs.biochem.0c00803] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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8
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α 2-Macroglobulin-like protein 1 can conjugate and inhibit proteases through their hydroxyl groups, because of an enhanced reactivity of its thiol ester. J Biol Chem 2020; 295:16732-16742. [PMID: 32978260 PMCID: PMC7864068 DOI: 10.1074/jbc.ra120.015694] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/18/2020] [Indexed: 11/08/2022] Open
Abstract
Proteins in the α-macroglobulin (αM) superfamily use thiol esters to form covalent conjugation products upon their proteolytic activation. αM protease inhibitors use theirs to conjugate proteases and preferentially react with primary amines (e.g. on lysine side chains), whereas those of αM complement components C3 and C4B have an increased hydroxyl reactivity that is conveyed by a conserved histidine residue and allows conjugation to cell surface glycans. Human α2-macroglobulin-like protein 1 (A2ML1) is a monomeric protease inhibitor but has the hydroxyl reactivity-conveying histidine residue. Here, we have investigated the role of hydroxyl reactivity in a protease inhibitor by comparing recombinant WT A2ML1 and the A2ML1 H1084N mutant in which this histidine is removed. Both of A2ML1s' thiol esters were reactive toward the amine substrate glycine, but only WT A2ML1 reacted with the hydroxyl substrate glycerol, demonstrating that His-1084 increases the hydroxyl reactivity of A2ML1's thiol ester. Although both A2ML1s conjugated and inhibited thermolysin, His-1084 was required for the conjugation and inhibition of acetylated thermolysin, which lacks primary amines. Using MS, we identified an ester bond formed between a thermolysin serine residue and the A2ML1 thiol ester. These results demonstrate that a histidine-enhanced hydroxyl reactivity can contribute to protease inhibition by an αM protein. His-1084 did not improve A2ML1's protease inhibition at pH 5, indicating that A2ML1's hydroxyl reactivity is not an adaption to its acidic epidermal environment.
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Biochemical mechanisms of aggregation in TGFBI-linked corneal dystrophies. Prog Retin Eye Res 2020; 77:100843. [DOI: 10.1016/j.preteyeres.2020.100843] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 12/22/2022]
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The serine protease HtrA1 cleaves misfolded transforming growth factor β-induced protein (TGFBIp) and induces amyloid formation. J Biol Chem 2019; 294:11817-11828. [PMID: 31197037 PMCID: PMC6682723 DOI: 10.1074/jbc.ra119.009050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/07/2019] [Indexed: 12/14/2022] Open
Abstract
The serine protease high-temperature requirement protein A1 (HtrA1) is associated with protein-misfolding disorders such as Alzheimer's disease and transforming growth factor β-induced protein (TGFBIp)-linked corneal dystrophy. In this study, using several biochemical and biophysical approaches, including recombinant protein expression, LC-MS/MS and 2DE analyses, and thioflavin T (ThT) fluorescence assays for amyloid fibril detection, and FTIR assays, we investigated the role of HtrA1 both in normal TGFBIp turnover and in corneal amyloid formation. We show that HtrA1 can cleave WT TGFBIp but prefers amyloidogenic variants. Corneal TGFBIp is extensively processed in healthy people, resulting in C-terminal degradation products spanning the FAS1-4 domain of TGFBIp. We show here that HtrA1 cleaves the WT FAS1-4 domain only inefficiently, whereas the amyloidogenic FAS1-4 mutations transform this domain into a considerably better HTRA1 substrate. Moreover, HtrA1 cleavage of the mutant FAS1-4 domains generated peptides capable of forming in vitro amyloid aggregates. Significantly, these peptides have been previously identified in amyloid deposits in vivo, supporting the idea that HtrA1 is a causative agent for TGFBIp-associated amyloidosis in corneal dystrophy. In summary, our results indicate that TGFBIp is an HtrA1 substrate and that some mutations in the gene encoding TGFBIp cause aberrant HtrA1-mediated processing that results in amyloidogenesis in corneal dystrophies.
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Mutation-Induced Deamidation of Corneal Dystrophy-Related Transforming Growth Factor β-Induced Protein. Biochemistry 2017; 56:6470-6480. [PMID: 29140698 DOI: 10.1021/acs.biochem.7b00668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mutations in the transforming growth factor β-induced protein (TGFBIp) cause phenotypically diverse corneal dystrophies, where protein aggregation in the cornea leads to severe visual impairment. Previous studies have shown a relationship between mutant-specific corneal dystrophy phenotypes and the thermodynamic stability of TGFBIp. Using liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance (NMR), we investigated correlations between the structural integrity of disease-related mutants of the fourth FAS1 domain (FAS1-4) and deamidation of TGFBIp residue Asn622. We observed a high rate of Asn622 deamidation in the A546D and A546D/P551Q FAS1-4 mutants that were both largely unstructured as determined by NMR. Conversely, the more structurally organized A546T and V624M FAS1-4 mutants had reduced deamidation rates, suggesting that a folded and stable FAS1-4 domain precludes Asn622 deamidation. Wild-type, R555Q, and R555W FAS1-4 mutants displayed very slow deamidation, which agrees with their similar and ordered NMR structures, where Asn622 is in a locked conformation. We confirmed the FAS1-4 mutational effect on deamidation rates in full-length TGFBIp mutants and found a similar ranking compared to that of the FAS1-4 domain alone. Consequently, the deamidation rate of Asn622 can be used to predict the structural effect of the many destabilizing and/or stabilizing mutations reported for TGFBIp. In addition, the deamidation of Asn622 may influence the pathophysiology of TGFBIp-induced corneal dystrophies.
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Proteomic profiling of TGFBI-null mouse corneas reveals only minor changes in matrix composition supportive of TGFBI knockdown as therapy against TGFBI-linked corneal dystrophies. FEBS J 2017; 285:101-114. [PMID: 29117645 DOI: 10.1111/febs.14321] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 09/25/2017] [Accepted: 11/03/2017] [Indexed: 12/27/2022]
Abstract
TGFBIp is a constituent of the extracellular matrix in many human tissues including the cornea, where it is one of the most abundant proteins expressed. TGFBIp interacts with Type I, II, IV, VI, and XII collagens as well as several members of the integrin family, suggesting it plays an important role in maintaining structural integrity and possibly corneal transparency as well. Significantly, more than 60 point mutations within the TGFBI gene have been reported to result in aberrant TGFBIp folding and aggregation in the cornea, resulting in severe visual impairment and blindness. Several studies have focused on targeting TGFBIp in the cornea as a therapeutic approach to treat TGFBI-linked corneal dystrophies, but the effect of this approach on corneal homeostasis and matrix integrity remained unknown. In the current study, we evaluated the histological and proteomic profiles of corneas from TGFBI-deficient mice as well as potential redundant functions of the paralogous protein POSTN. The absence of TGFBIp in mouse corneas did not grossly affect the collagen scaffold, and POSTN is unable to compensate for loss of TGFBIp. Proteomic comparison of wild-type and TGFBI-/- mice revealed 11 proteins were differentially regulated, including Type VI and XII collagens. However, as these alterations did not manifest at the macroscopic and behavioral levels, these data support partial or complete TGFBI knockdown as a potential therapy against TGFBI-linked corneal dystrophies. Lastly, in situ hybridization verified TGFBI mRNA in the epithelial cells but not in other cell types, supportive of a therapy directed specifically at this lineage.
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Structural and Functional Implications of Human Transforming Growth Factor β-Induced Protein, TGFBIp, in Corneal Dystrophies. Structure 2017; 25:1740-1750.e2. [PMID: 28988748 DOI: 10.1016/j.str.2017.09.001] [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: 06/12/2017] [Revised: 08/02/2017] [Accepted: 09/01/2017] [Indexed: 12/31/2022]
Abstract
A major cause of visual impairment, corneal dystrophies result from accumulation of protein deposits in the cornea. One of the proteins involved is transforming growth factor β-induced protein (TGFBIp), an extracellular matrix component that interacts with integrins but also produces corneal deposits when mutated. Human TGFBIp is a multi-domain 683-residue protein, which contains one CROPT domain and four FAS1 domains. Its structure spans ∼120 Å and reveals that vicinal domains FAS1-1/FAS1-2 and FAS1-3/FAS1-4 tightly interact in an equivalent manner. The FAS1 domains are sandwiches of two orthogonal four-stranded β sheets decorated with two three-helix insertions. The N-terminal FAS1 dimer forms a compact moiety with the structurally novel CROPT domain, which is a five-stranded all-β cysteine-knot solely found in TGFBIp and periostin. The overall TGFBIp architecture discloses regions for integrin binding and that most dystrophic mutations cluster at both molecule ends, within domains FAS1-1 and FAS1-4.
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LASIK surgery of granular corneal dystrophy type 2 patients leads to accumulation and differential proteolytic processing of transforming growth factor beta-induced protein (TGFBIp). Proteomics 2016; 16:539-43. [DOI: 10.1002/pmic.201500287] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/29/2015] [Accepted: 11/09/2015] [Indexed: 11/11/2022]
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Insight into the Protein Composition of Immunoglobulin Light Chain Deposits of Eyelid, Orbital and Conjunctival Amyloidosis. ACTA ACUST UNITED AC 2014; Suppl 8. [PMID: 26500418 DOI: 10.4172/jpb.s8-002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Amyloidosis is a disease characterized by the formation of extracellular amyloid deposits. Immunoglobulin light-chain amyloidosis can appear as a local disorder presenting with mild symptoms or as a life threatening systemic disease. The systemic form of immunoglobulin light-chain amyloidosis is the most common type of amyloidosis in western countries although it is a rare disease. Identification of the proteins forming amyloid fibrils is essential for the diagnosis of the disease and knowledge about the overall protein composition of the deposits may lead to a larger understanding of the deposition events thereby facilitating a more detailed picture of the molecular pathology. In this pilot study, we investigated the protein composition of amyloid deposits isolated from human specimens of the eyelid, conjunctiva, and orbit. Deposits and internal control tissue (patient tissue without apparent deposits) were procured by laser capture microdissection. Proteins in the captured amyloid and control samples were quantified by liquid chromatography tandem mass spectrometry using the label-free exponential modified Protein Abundance Index (emPAI) method. Immunoglobulin light chain kappa or lambda was found to be the most predominant protein in the amyloid deposits from the eyelid, conjunctiva, and orbit. Five proteins, apolipoprotein A-I, carboxypeptidase B2 (TAFI), complement component C9, fibulin-1 and plasminogen were found solely across all amyloid but not in the control tissue. In addition, the protein profiles identified apolipoprotein E and serum amyloid P component to be associated with the immunoglobulin light chain deposits across all three tissues analyzed. The method used in this study provided high sensitivity and specificity for the type of amyloid and may provide additional information on the pathology of the amyloid deposits in the ocular tissues studied.
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Proteomic investigation of cultivated fibroblasts from patients with mitochondrial short-chain acyl-CoA dehydrogenase deficiency. Mol Genet Metab 2014; 111:360-368. [PMID: 24485985 DOI: 10.1016/j.ymgme.2014.01.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/15/2014] [Accepted: 01/15/2014] [Indexed: 12/23/2022]
Abstract
Short-chain acyl-CoA dehydrogenase (SCAD) deficiency is a rare inherited autosomal recessive disorder with not yet well established mechanisms of disease. In the present study, the mitochondrial proteome of five symptomatic patients homozygous for missense variations in the SCAD gene ACADS was investigated in an extensive large-scale proteomic study to map protein perturbations linked to the disease. Fibroblast cultures of patient cells homozygous for either c.319C>T/p.Arg107Cys (n=2) or c.1138C>T/p.Arg380Trp (n=3) in ACADS, and healthy controls (normal human dermal fibroblasts), were studied. The mitochondrial proteome derived from these cultures was analyzed by label free proteomics using high mass accuracy nanoliquid chromatography tandem mass spectrometry (nanoLC-MS/MS). More than 300 mitochondrial proteins were identified and quantified. Thirteen proteins had significant alteration in protein levels in patients carrying variation c.319C>T in ACADS compared to controls and they belonged to various pathways, such as the antioxidant system and amino acid metabolism. Twenty-two proteins were found significantly altered in patients carrying variation c.1138C>T which included proteins associated with fatty acid β-oxidation, amino acid metabolism and protein quality control system. Three proteins were found significantly regulated in both patient groups: adenylate kinase 4 (AK4), nucleoside diphosphate kinase A (NME1) and aldehyde dehydrogenase family 4 member A1 (ALDH4A1). Proteins AK4 and NME1 deserve further investigation because of their involvement in energy reprogramming, cell survival and proliferation with relevance for SCAD deficiency and related metabolic disorders.
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Oxidative stability of marine phospholipids in the liposomal form and their applications. Lipids 2010; 46:3-23. [PMID: 21088919 DOI: 10.1007/s11745-010-3496-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 10/26/2010] [Indexed: 12/15/2022]
Abstract
Marine phospholipids (MPL) have attracted a great deal of attention recently as they are considered to have a better bioavailability, a better resistance towards oxidation and a higher content of eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) than oily triglycerides (fish oil) from the same source. Due to their tight intermolecular packing conformation at the sn-2 position and their synergism with α-tocopherol present in MPL extracts, they can form stable liposomes which are attractive ingredients for food or feed applications. However, MPL are still susceptible to oxidation as they contain large amounts polyunsaturated fatty acids and application of MPL in food and aquaculture industries is therefore a great challenge for researchers. Hence, knowledge on the oxidative stability of MPL and the behavior of MPL in food and feed systems is an important issue. For this reason, this review was undertaken to provide the industry and academia with an overview of (1) the stability of MPL in different forms and their potential as liposomal material, and (2) the current applications and future prospects of MPL in both food and aquaculture industries with special emphasis on MPL in the liposomal form.
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A biomechanical evaluation of the relative load change in the joints of the wrist with ulnar shortening: a 'handbag' model. J Hand Surg Eur Vol 2009; 34:724-9. [PMID: 19687087 DOI: 10.1177/1753193409337965] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The wrist joint is loaded not only while applying a proximally directed load but also, less obviously, while carrying a handbag. Ulnar shortening reduces pressure and relieves pain in the ulnocarpal joint. The present study evaluated the pressure distribution in the wrist joints with ulnar shortening and lengthening when applying traction to the flexed fingers while the fingers were loaded and unloaded. The compressive forces in the loaded wrist were distributed with 67% across the radiocarpal joint and 33% across the ulnocarpal joint. Shortening the ulna by 3 mm increased load in the radius to 80%. Lengthening of the ulna by 1 mm increased its load to 55%. The load share of the distal radioulnar joint was constant even when the ulna was shortened 3-4 mm. It seems advisable to shorten the ulna by 3 mm, since the increased load in the related joints are constant within a range of -2 to -4 mm.
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Influence of fish oil supplementation on in vivo and in vitro oxidation resistance of low-density lipoprotein in type 2 diabetes. Eur J Clin Nutr 2003; 57:713-20. [PMID: 12771973 DOI: 10.1038/sj.ejcn.1601602] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2002] [Revised: 07/22/2002] [Accepted: 07/24/2002] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Fish oil supplement has been proposed as a non-pharmacological strategy to correct the atherogenic lipid profile associated with type 2 diabetes mellitus. However, fish oil may have deleterious effects on lipid peroxidation and glycemic control. DESIGN In this study, 44 type 2 diabetic patients were randomized to vitamin E standardized (53.6 mg/day) supplementation (capsules) with 4 g daily of either fish oil (n=23) or corn oil (n=21) for 8 weeks preceded by a 4 week run-in period of corn oil supplementation. LDL was isolated by density gradient ultracentrifugation and oxidized in vitro with Cu(2+). As a marker of in vivo oxidation malondialdehyde concentration in LDL (LDL-MDA) was measured. RESULTS Fish oil reduced both mean lag time (before, 57.8; after, 48.8 min, P<0.001) and mean propagation rate (before, 0.018 DeltaOD/min; after, 0.015 DeltaOD/min, P<0.001), whereas corn oil had no influence on lag time and propagation rate. The changes in lag time and propagation rate differed significantly between fish oil and corn oil treatment. LDL-MDA changes differed borderline significantly between groups (FO, 110.4 pmol/mg protein; CO, 6.7 pmol/mg protein; P=0.057). Fish oil supplementation had no influence on glycemic control as assessed from HbA(1c) and fasting blood glucose. CONCLUSION According to our findings, fish oil supplementation leads to increased in vivo oxidation and increased in vitro oxidation susceptibility of LDL particles. More studies are needed to clarify the clinical importance of this finding.
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Arthroscopy of the proximal interphalangeal joints of the finger. JOURNAL OF HAND SURGERY (EDINBURGH, SCOTLAND) 2002; 27:253-5. [PMID: 12074613 DOI: 10.1054/jhsb.2001.0725] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cadaveric studies were carried out to evaluate the technique, portals and possible indications for arthroscopy of the proximal interphalangeal joints of the finger. We suggest horizontal placement of the hand instead of using a traction tower, as it is important to be able to flex the joint freely. The recommended arthroscopic portals are either between the central slip and the lateral bands of the extensor mechanism or between the lateral band and the collateral ligament. A blunt technique of introduction is used to avoid iatrogenic cartilage damage and possible digital nerve injury.
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Abstract
Winchester syndrome was first described in 1969 and since then nine patients have been reported in the literature. The syndrome is characterized by short stature, coarse face, corneal opacities, generalized osteolysis and progressive painful arthropathy with joint stiffness and contractures of distal phalanges in combination with skin changes. The etiology is unknown. Parental consanguinity supports autosomal inheritance. The diagnosis is based on clinical and radiological manifestations. We describe a case in a 7-year-old Pakistani boy.
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Effect of meal fat quality on oxidation resistance of postprandial VLDL and LDL particles and plasma triacylglycerol level. Br J Nutr 2000; 84:855-63. [PMID: 11177202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
This study was performed to examine the postprandial effects of meals containing dietary fats, with their natural fatty acid composition and tocopherol content, on the plasma triacylglycerols (TG) and tocopherols and on the resistance of VLDL and LDL to oxidation. On six separate days eighteen healthy male subjects were given low-fat meals (LF) or the LF meals enriched with sunflower oil (SO), rapeseed oil (RO), olive oil (OO), palm oil (PO), or butter (B) in a crossover design. The fat-rich meals all resulted in similar postprandial TG responses while the LF test meal did not increase plasma TG level. The postprandial plasma fatty acid profile changed to resemble the fatty acid composition of the ingested test fat. The alpha-tocopherol:gamma-tocopherol ratios in postprandial plasma and VLDL samples were greater than in the test fats. We found that the resistance of VLDL particles to oxidation in the postprandial state as assessed from lag time was increased after the PO-rich meal as compared with the SO-rich meal (p = 0.018), and the propagation rate was greater after the SO- and RO-rich meals compared with the others (p < 0.001). The resistance of LDL particles to oxidation was unaffected by the meals. In postprandial VLDL samples, the content of alpha-tocopherol was greater after the OO- and SO-rich meals compared with the meal rich in PO (P = 0.034 and 0.042 respectively). The gamma-tocopherol content of VLDL was highest after RO-meal as compared with all other test meals (P = 0.0019), and higher after SO as compared with B (P = 0.0148). Large individual differences were noted. In conclusion, meals enriched with different fats lead to the formation of VLDL particles with varying resistance to oxidation.
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Repeated digital nerve block for pain control after tenolysis. SCANDINAVIAN JOURNAL OF PLASTIC AND RECONSTRUCTIVE SURGERY AND HAND SURGERY 2000; 34:257-8. [PMID: 11020924 DOI: 10.1080/02844310050159855] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We describe a way of achieving immediate painfree mobilisation after tenolysis or tenosynovectomy in Zone II. Bupivacaine is instilled along the flexor tendon sheath through a thin percutaneous catheter with an antibacterial filter.
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Hyperextension injury to the PIP joint or to the MP joint of the thumb--a clinical study. SCANDINAVIAN JOURNAL OF PLASTIC AND RECONSTRUCTIVE SURGERY AND HAND SURGERY 1998; 32:317-21. [PMID: 9785437 DOI: 10.1080/02844319850158679] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
We present a prospective study of the diagnosis and clinical course of 60 patients with 57 pure hyperextension injuries to the proximal interphalangeal (PIP) joint of the long fingers (fingers 2-5) and seven injuries to the metacarpophalangeal (MP) joint of the thumb. Thirty four of the injuries (57%) were related to ball sports, and the ulnar fingers of the non-dominant hand were usually affected. There were 24 avulsion fractures at the site of the insertion of the volar plate on to the middle phalanx. Twelve (20%) initially presented with hyperextension instability, and this was usually associated with an avulsion fracture. Thirty four of the patients (57%) had symptoms for less than one month, while 10 (17%) complained of symptoms six months after the injury. Severe complications such as daily pain and stiffness were encountered in three cases. The triad sign (pain on extreme flexion and extension) was of no use as a diagnostic or prognostic factor, nor did the radiographic stress-view help to identify acute instability of the joint.
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25
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[Ultrasonically guided gastroscopically assisted percutaneous internal drainage of pancreatic pseudocysts]. Ugeskr Laeger 1996; 158:1670-3. [PMID: 8644410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Non-surgical procedures are increasingly being used for drainage of pancreatic pseudocysts. We describe the results of placement of a double pigtail cystogastric stent under ultrasonographic and gastroscopic guidance. The stent was placed in 22 of 25 pseudocysts. There was no mortality associated with the procedure and the total complication rate was 20%. The cysts resolved in all patients and 87% reported reduction of abdominal pain. The median stent-time was 347 days and there were no cyst recurrences or complications during that time. After removal of the stent four out of 19 patients had recurrences. After placement of a second stent in these four patients there were no recurrences. Treatment with a cystogastric stent is comparable to surgical cystogastrostomy as regards to results and has fewer complications.
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Prediction of hormone responsiveness by mammographic parenchymal pattern in advanced primary breast cancer. Breast Cancer Res Treat 1992; 23:219-22. [PMID: 1463861 DOI: 10.1007/bf01833518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ninety-two women with advanced, unilateral breast cancer were classified according to the Wolfe and Nottingham classifications of mammographic parenchymal pattern (MPP). Both classifications of MPP were significantly correlated to the estrogen receptor (ER) status of the breast carcinoma, but could not be used for prediction of response to hormonal therapy. Age distribution was significantly different among Wolfe types as well as between ER groups, but a multiple regression analysis showed that both age and Wolfe pattern were significant and independent predictors of the ER status.
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Renal candida infections. Diagnosis by ultrasonography. ROFO-FORTSCHR RONTG 1988; 149:417-9. [PMID: 2845512 DOI: 10.1055/s-2008-1048371] [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: 01/02/2023]
Abstract
Sonographic features of renal candidiasis are nonspecific. Ultrasonically guided aspiration and culture is a quick and easy way to reach the exact diagnosis. We describe one case of parenchymal and one case of pelvic candidiasis diagnosed by percutaneous aspiration.
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Abstract
A re-examination study was made of 18 cases of histologically verified adenosis tumour from 12 different hospitals in Denmark. Four mammographic appearances could be identified. No pathognomonic sign or appearance could be identified. The median age of the patients was 42 years. The mean diameter of the 'tumour' was 2.1 cm. The diagnostic problem of malignant and benign breast disease is discussed.
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Abstract
Utah mortality rates for cerebrovascular disease (ICD numbers 430--438) are 13% below U.S. rates. About 70% of Utahns are members of the Church of Jesus Christ of Latter-day Saints, commonly called Mormons of LDS, which proscribes use of tobacco and alcohol. Other studies on this group have found significantly lower occurrence of many cancers and ischemic heart disease. We tested the hypothesis that Utah's lower cerebrovascular disease (CBVD) mortality was contributed by the LDS population. We classified by religion all CBVD deaths (2,521) (except subarachnoid hemorrhage and cerebral embolism) occurring in the state in 1968--1971. No significant difference was found between LDS and non-LDS, but both groups had mortality rates below U.S. expectation. Although recent studies have reported smoking to be a risk factor for CBVD, we found no consistent difference between the LDS and non-LDS, even in the younger age groups. The results do not support the hypothesis that tobacco is an important etiologic agent in CBVD mortality.
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[Ecthyma gangrenosum]. Ugeskr Laeger 1981; 143:936-7. [PMID: 7281292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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31
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[Non-palpable breast cancer]. Ugeskr Laeger 1981; 143:334-6. [PMID: 7210239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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32
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[Value of arthrography of the knee in the diagnosis meniscal lesions]. Ugeskr Laeger 1980; 142:2759-60. [PMID: 6893774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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33
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[Mondor's disease. Clinical and radiologic description of 12 cases]. Ugeskr Laeger 1979; 141:1141-2. [PMID: 442246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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