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Maier J, Kandulski A, Donlon NE, Werner JM, Mehrl A, Müller M, Doenecke A, Schlitt HJ, Hornung M, Weiss ARR. Endoscopic vacuum therapy significantly improves clinical outcomes of anastomotic leakages after 2-stage, 3-stage, and transhiatal esophagectomies. Langenbecks Arch Surg 2023; 408:90. [PMID: 36790506 PMCID: PMC9931828 DOI: 10.1007/s00423-023-02826-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 01/29/2023] [Indexed: 02/16/2023]
Abstract
BACKGROUND Anastomotic leakages after esophagectomies continue to constitute significant morbidity and mortality. Intrathoracic anastomoses pose a high risk for mediastinitis, sepsis, and death, if a leak is not addressed timely and appropriately. However, there are no standardized treatment recommendations or algorithms as for how to treat these leakages. METHODS The study included all patients at the University Hospital Regensburg, who developed an anastomotic leakage after esophagectomy with gastric pull-up reconstruction from 2007 to 2022. Patients receiving conventional treatment options for an anastomotic leakage (stents, drainage tubes, clips, etc.) were compared to patients receiving endoscopic vacuum-assisted closure (eVAC) therapy as their mainstay of treatment. Treatment failure was defined as cervical esophagostomy formation or death. RESULTS In total, 37 patients developed an anastomotic leakage after esophagectomy with a gastric pull-up reconstruction. Twenty patients were included into the non-eVAC cohort, whereas 17 patients were treated with eVAC. Treatment failure was observed in 50% of patients (n = 10) in the non-eVAC cohort and in 6% of patients (n = 1) in the eVAC cohort (p < 0.05). The 90-day mortality in the non-eVAC cohort was 15% (n = 3) compared to 6% (n = 1) in the eVAC cohort. Cervical esophagostomy formation was required in 40% of cases (n = 8) in the non-eVAC cohort, whereas no patient in the eVAC cohort underwent cervical esophagostomy formation. CONCLUSION eVAC therapy for leaking esophagogastric anastomoses appears to be superior to other treatment strategies as it significantly reduces morbidity and mortality. Therefore, we suggest eVAC as an essential component in the treatment algorithm for anastomotic leakages following esophagectomies, especially in patients with intrathoracic anastomoses.
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Affiliation(s)
- Jonas Maier
- Department of Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - A Kandulski
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology, and Infectious Diseases, University Hospital Regensburg, Regensburg, Germany
| | - N E Donlon
- Department of Surgery, Mater Misericordiae University Hospital, Dublin 7, Ireland
| | - J M Werner
- Department of Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - A Mehrl
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology, and Infectious Diseases, University Hospital Regensburg, Regensburg, Germany
| | - M Müller
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology, Rheumatology, and Infectious Diseases, University Hospital Regensburg, Regensburg, Germany
| | - A Doenecke
- Department of Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - H J Schlitt
- Department of Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - M Hornung
- Department of Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - A R R Weiss
- Department of Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
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Rosen J, Ceccon G, Bauer EK, Werner JM, Kabbasch C, Fink GR, Langen KJ, Galldiks N. P14.41 Cost-effectiveness of FET PET for early treatment response assessment in glioma patients following adjuvant temozolomide chemotherapy. Neuro Oncol 2021. [DOI: 10.1093/neuonc/noab180.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
BACKGROUND
In light of increasing healthcare costs, higher medical expenses should be justified socio-economically. Therefore, we calculated the effectiveness and cost-effectiveness of PET using the radiolabeled amino acid O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) compared to conventional MRI for early identification of responders to adjuvant temozolomide chemotherapy. A recent study in IDH-wildtype glioma patients suggested that after two cycles, FET-PET parameter changes predicted a significantly longer survival while MRI changes were not significant.
MATERIALS AND METHODS
To determine the effectiveness and cost-effectiveness of serial FET-PET imaging, we analyzed published clinical data and calculated the associated costs in the context of the German healthcare system.Based on a decision-tree model, FET-PET and MRI’s effectiveness was calculated, i.e., the probability to correctly identify a responder as defined by an overall survival ≥15 months. To determine the cost-effectiveness, the incremental cost-effectiveness ratio (ICER) was calculated, i.e., the cost for each additionally identified responder by FET-PET who would have remained undetected by MRI. The robustness of the results was tested by deterministic and probabilistic (Monte Carlo simulation) sensitivity analyses.
RESULTS
Compared to MRI, FET-PET increases the rate of correctly identified responders to chemotherapy by 26%; thus, four patients need to be examined by FET-PET to identify one additional responder. Considering the respective cost for serial FET-PET and MRI, the ICER resulted in €4,396.83 for each additional correctly identified responder by FET-PET. The sensitivity analyses confirmed the robustness of the results.
CONCLUSION
In contrast to conventional MRI, the model suggests that FET PET is cost-effective in terms of ICER values. Concerning the high cost of temozolomide, the integration of FET-PET has the potential to avoid premature chemotherapy discontinuation at a reasonable cost.
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Affiliation(s)
- J Rosen
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - G Ceccon
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - E K Bauer
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - J M Werner
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - C Kabbasch
- Department of Neuroradiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - G R Fink
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
| | - K J Langen
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
- Dept. of Nuclear Medicine, University Hospital Aachen, Aachen, Germany
| | - N Galldiks
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
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Bauer EK, Stoffels G, Blau T, Reifenberger G, Werner JM, Lohmann P, Rapp M, Fink GR, Langen K, Galldiks N. P14.29 Prediction of overall survival in patients with malignant glioma using dynamic O-(2-[18F]-fluoroethyl)-L-tyrosine PET. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Characterization of gliomas according to the revised World Health Organization (WHO) classification of 2016 has gained major importance regarding prognostication. The present study aimed at exploring the prognostic value of dynamic O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET in newly diagnosed and molecularly defined astrocytic high-grade glioma (HGG) of the WHO grades III or IV.
MATERIAL AND METHODS
Before initiation of treatment, dynamic FET PET imaging was performed in patients with newly diagnosed glioblastoma (GBM) and anaplastic astrocytoma (AA). Static FET PET parameters such as maximum and mean tumor/brain ratios (TBRmax/mean), as well as the dynamic FET PET parameters time-to-peak (TTP) and slope, were obtained. The predictive ability of FET PET parameters was evaluated with regard to the overall survival (OS). Using ROC analyses, threshold values for FET PET parameters were obtained. Subsequently, univariate Kaplan-Meier and multivariate Cox regression survival analyses were performed to assess their predictive power for OS.
RESULTS
Sixty patients (45 GBM, 15 AA) of two university centers were retrospectively identified. Patients with a methylated MGMT promoter as well as with an IDH mutation had a significantly longer OS (both P<0.001). Furthermore, ROC analysis revealed in IDH-wildtype HGG (n=45) that a TTP>25 minutes (AUC, 0.90; sensitivity, 90%; specificity, 87%; P<0.001) was highly prognostic for a longer OS (29 vs. 12 months; P<0.001). Besides a complete resection and a methylated MGMT promoter, TTP remained significant in the multivariate survival analysis (P=0.002, P=0.016, and P=0.003, respectively), indicating an independent predictor for OS. In contrast, both TBRmax and TBRmean were not prognostic (AUC, 0.37 and 0.32, respectively).
CONCLUSION
Data suggest that within the subgroup of patients with newly diagnosed and untreated IDH-wildtype GBM and AA, dynamic FET PET additionally allows the identification of patients with an improved OS.
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Affiliation(s)
- E K Bauer
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - G Stoffels
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
| | - T Blau
- Dept. of Neuropathology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - G Reifenberger
- Dept. of Neuropathology, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
- Center of Integrated Oncology (CIO), Universities of Aachen, Bonn, Cologne and Duesseldorf, Aachen, Bonn, Cologne and Duesseldorf, Germany
| | - J M Werner
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - P Lohmann
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
| | - M Rapp
- Dept. of Neurosurgery, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - G R Fink
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
| | - K Langen
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
- Dept. of Nuclear Medicine, University of Aachen, Aachen, Germany
| | - N Galldiks
- Dept. of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany
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Verloh N, Probst U, Utpatel K, Zeman F, Brennfleck F, Werner JM, Fellner C, Stroszczynski C, Evert M, Wiggermann P, Haimerl M. Influence of hepatic fibrosis and inflammation: Correlation between histopathological changes and Gd-EOB-DTPA-enhanced MR imaging. PLoS One 2019; 14:e0215752. [PMID: 31083680 PMCID: PMC6513096 DOI: 10.1371/journal.pone.0215752] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/08/2019] [Indexed: 02/07/2023] Open
Abstract
Objective To evaluate the influence of an active inflammatory process in the liver on Gd-EOB-DTPA-enhanced MR imaging in patients with different degrees of fibrosis/cirrhosis. Material and methods Overall, a number of 91 patients (61 men and 30 women; mean age 58 years) were included in this retrospective study. The inclusion criteria for this study were Gd-EOB-DTPA-enhanced MRI of the liver and histopathological evaluation of fibrotic and inflammatory changes. T1-weighted VIBE sequences of the liver with fat suppression were evaluated to determine the relative signal change (RE) between native and hepatobiliary phase (20min). In simple and multiple linear regression analyses, the influence of liver fibrosis/cirrhosis (Ishak score) and the histopathological degree of hepatitis (Modified Hepatic Activity Index, mHAI) on RE were evaluated. Results RE decreased significantly with increasing liver fibrosis/cirrhosis (p < 0.001) and inflammation (mHAI, p = 0.004). In particular, a correlation between RE and periportal or periseptal boundary zone hepatitis (moth feeding necrosis, mHAI A, p = 0.001) and portal inflammation (mHAI D, p < 0.001) was observed. In multiple linear regression analysis, both the degree of inflammation and the degree of fibrosis were significant predictors for RE (p < 0.01). Conclusion The results of this study suggest that the MR-based hepatic enhancement index RE is not only influenced by the degree of fibrosis, but also by the degree of inflammation.
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Affiliation(s)
- N. Verloh
- Department of Radiology, University Hospital Regensburg, Regensburg, Germany
- * E-mail:
| | - U. Probst
- Department of Radiology, University Hospital Regensburg, Regensburg, Germany
| | - K. Utpatel
- Department of Pathology, University Regensburg, Regensburg, Germany
| | - F Zeman
- Center for Clinical Trials, University Hospital Regensburg, Regensburg, Germany
| | - F. Brennfleck
- Department of Surgery, University Hospital Regensburg, Regensburg, Germany
| | - J. M. Werner
- Department of Surgery, University Hospital Regensburg, Regensburg, Germany
| | - C. Fellner
- Department of Radiology, University Hospital Regensburg, Regensburg, Germany
| | - C. Stroszczynski
- Department of Radiology, University Hospital Regensburg, Regensburg, Germany
| | - M. Evert
- Department of Pathology, University Regensburg, Regensburg, Germany
| | - P. Wiggermann
- Department of Radiology and Nuclear Medicine, Hospital Braunschweig, Braunschweig, Germany
| | - M. Haimerl
- Department of Radiology, University Hospital Regensburg, Regensburg, Germany
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Erskine PT, Fokas A, Muriithi C, Rehman H, Yates LA, Bowyer A, Findlow IS, Hagan R, Werner JM, Miles AJ, Wallace BA, Wells SA, Wood SP, Cooper JB. X-ray, spectroscopic and normal-mode dynamics of calexcitin: structure-function studies of a neuronal calcium-signalling protein. ACTA ACUST UNITED AC 2015; 71:615-31. [PMID: 25760610 DOI: 10.1107/s1399004714026704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 12/04/2014] [Indexed: 01/28/2023]
Abstract
The protein calexcitin was originally identified in molluscan photoreceptor neurons as a 20 kDa molecule which was up-regulated and phosphorylated following a Pavlovian conditioning protocol. Subsequent studies showed that calexcitin regulates the voltage-dependent potassium channel and the calcium-dependent potassium channel as well as causing the release of calcium ions from the endoplasmic reticulum (ER) by binding to the ryanodine receptor. A crystal structure of calexcitin from the squid Loligo pealei showed that the fold is similar to that of another signalling protein, calmodulin, the N- and C-terminal domains of which are known to separate upon calcium binding, allowing interactions with the target protein. Phosphorylation of calexcitin causes it to translocate to the cell membrane, where its effects on membrane excitability are exerted and, accordingly, L. pealei calexcitin contains two protein kinase C phosphorylation sites (Thr61 and Thr188). Thr-to-Asp mutations which mimic phosphorylation of the protein were introduced and crystal structures of the corresponding single and double mutants were determined, which suggest that the C-terminal phosphorylation site (Thr188) exerts the greatest effects on the protein structure. Extensive NMR studies were also conducted, which demonstrate that the wild-type protein predominantly adopts a more open conformation in solution than the crystallographic studies have indicated and, accordingly, normal-mode dynamic simulations suggest that it has considerably greater capacity for flexible motion than the X-ray studies had suggested. Like calmodulin, calexcitin consists of four EF-hand motifs, although only the first three EF-hands of calexcitin are involved in binding calcium ions; the C-terminal EF-hand lacks the appropriate amino acids. Hence, calexcitin possesses two functional EF-hands in close proximity in its N-terminal domain and one functional calcium site in its C-terminal domain. There is evidence that the protein has two markedly different affinities for calcium ions, the weaker of which is most likely to be associated with binding of calcium ions to the protein during neuronal excitation. In the current study, site-directed mutagenesis has been used to abolish each of the three calcium-binding sites of calexcitin, and these experiments suggest that it is the single calcium-binding site in the C-terminal domain of the protein which is likely to have a sensory role in the neuron.
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Affiliation(s)
- P T Erskine
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - A Fokas
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - C Muriithi
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - H Rehman
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - L A Yates
- Centre of Biological Sciences, University of Southampton, Southampton SO17 1BJ, England
| | - A Bowyer
- Centre of Biological Sciences, University of Southampton, Southampton SO17 1BJ, England
| | - I S Findlow
- Centre of Biological Sciences, University of Southampton, Southampton SO17 1BJ, England
| | - R Hagan
- Centre of Biological Sciences, University of Southampton, Southampton SO17 1BJ, England
| | - J M Werner
- Centre of Biological Sciences, University of Southampton, Southampton SO17 1BJ, England
| | - A J Miles
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, England
| | - B A Wallace
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, England
| | - S A Wells
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
| | - S P Wood
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - J B Cooper
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
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Erskine PT, Beaven GDE, Hagan R, Findlow IS, Werner JM, Wood SP, Vernon J, Giese KP, Fox G, Cooper JB. Structure of the Neuronal Protein Calexcitin Suggests a Mode of Interaction in Signalling Pathways of Learning and Memory. J Mol Biol 2006; 357:1536-47. [PMID: 16497326 DOI: 10.1016/j.jmb.2006.01.083] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 01/22/2006] [Accepted: 01/23/2006] [Indexed: 10/25/2022]
Abstract
The three-dimensional structure of the neuronal calcium-sensor protein calexcitin from Loligo pealei has been determined by X-ray analysis at a resolution of 1.8A. Calexcitin is up-regulated following Pavlovian conditioning and has been shown to regulate potassium channels and the ryanodine receptor. Thus, calexcitin is implicated in neuronal excitation and plasticity. The overall structure is predominantly helical and compact with a pronounced hydrophobic core between the N and C-terminal domains of the molecule. The structure consists of four EF-hand motifs although only the first three EF hands are involved in binding calcium ions; the C-terminal EF-hand lacks the amino acids required for calcium binding. The overall structure is quite similar to that of the sarcoplasmic calcium-binding protein from Amphioxus although the sequence identity is very low at 31%. The structure shows that the two amino acids of calexcitin phosphorylated by protein kinase C are close to the domain interface in three dimensions and thus phosphorylation is likely to regulate the opening of the domains that is probably required for binding to target proteins. There is evidence that calexcitin is a GTPase and the residues, which have been implicated by mutagenesis in its GTPase activity, are in a short but highly conserved region of 3(10) helix close to the C terminus. This helix resides in a large loop that is partly sandwiched between the N and C-terminal domains suggesting that GTP binding may also require or may cause domain opening. The structure possesses a pronounced electropositive crevice in the vicinity of the 3(10) helix, that might provide an initial docking site for the triphosphate group of GTP. These findings elucidate a number of the reported functions of calexcitin with implications for neuronal signalling.
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Affiliation(s)
- P T Erskine
- School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK
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Saha S, Boyd J, Werner JM, Knott V, Handford PA, Campbell ID, Downing AK. Solution structure of the LDL receptor EGF-AB pair: a paradigm for the assembly of tandem calcium binding EGF domains. Structure 2001; 9:451-6. [PMID: 11435110 DOI: 10.1016/s0969-2126(01)00606-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND From the observed structure and sequence of a pair of calcium binding (cb) epidermal growth factor-like (EGF) domains from human fibrillin-1, we proposed that many tandem cbEGF domains adopt a conserved relative conformation. The low-density lipoprotein receptor (LDLR), which is functionally unrelated to fibrillin-1, contains a single pair of EGF domains that was chosen for study in the validation of this hypothesis. The LDLR is the protein that is defective in familial hypercholesterolaemia, a common genetic disorder that predisposes individuals to cardiovascular complications and premature death. RESULTS Here, we present the solution structure of the first two EGF domains from the LDL receptor, determined using conventional NMR restraints and residual dipolar couplings. The cbEGF domains have an elongated, rod-like arrangement, as predicted. The new structure allows a detailed assessment of the consequences of mutations associated with familial hypercholesterolaemia to be made. CONCLUSIONS The validation of the conserved arrangement of EGF domains in functionally distinct proteins has important implications for structural genomics, since multiple tandem cbEGF pairs have been identified in many essential proteins that are implicated in human disease. Our results provide the means to use homology modeling to probe structure-function relationships in this diverse family of proteins and may hold the potential for the design of novel diagnostics and therapies in the future.
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Affiliation(s)
- S Saha
- Division of Structural Biology, Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, United Kingdom
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Arold ST, Ulmer TS, Mulhern TD, Werner JM, Ladbury JE, Campbell ID, Noble ME. The role of the Src homology 3-Src homology 2 interface in the regulation of Src kinases. J Biol Chem 2001; 276:17199-205. [PMID: 11278857 DOI: 10.1074/jbc.m011185200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The regulatory fragment of Src kinases, comprising Src homology (SH) 3 and SH2 domains, is responsible for controlled repression of kinase activity. We have used a multidisciplinary approach involving crystallography, NMR, and isothermal titration calorimetry to study the regulatory fragment of Fyn (FynSH32) and its interaction with a physiological activator: a fragment of focal adhesion kinase that contains both phosphotyrosine and polyproline motifs. Although flexible, the preferred disposition of SH3 and SH2 domains in FynSH32 resembles the inactive forms of Hck and Src, differing significantly from LckSH32. This difference, which results from variation in the SH3-SH2 linker sequences, will affect the potential of the regulatory fragments to repress kinase activity. This surprising result implies that the mechanism of repression of Src family members may vary, explaining functional distinctions between Fyn and Lck. The interaction between FynSH32 and focal adhesion kinase is restricted to the canonical SH3 and SH2 binding sites and does not affect the dynamic independence of the two domains. Consequently, the interaction shows no enhancement by an avidity effect. Such an interaction may have evolved to gain specificity through an extended recognition site while maintaining rapid dissociation after signaling.
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Affiliation(s)
- S T Arold
- Laboratory of Molecular Biophysics and Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
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Abstract
The lone (1)F2(2)F2 modular pair of fibronectin is found in the collagen-binding region. This exclusive localization suggests the (1)F2(2)F2 pair plays an important role in the recognition of collagen. However, no information is currently available about the interaction between the two F2 modules and, thus, the orientation of their putative collagen-binding sites with respect to one another. Comparison of a variety of high-resolution NMR parameters from the F2 modules in isolation and the (1)F2(2)F2 pair was used to establish the extent of interaction between the F2 modules in the pair. Chemical shifts of the F2 modules and the (1)F2(2)F2 pair indicate that the structures of the modules are preserved in the pair and that, with the exception of the covalent linkage, they do not interact. (15)N NMR relaxation data identify significant motion occurring in the linker region of the (1)F2(2)F2 pair, and analyses of the anisotropic diffusion properties of the (1)F2(2)F2 pair are consistent with the modules in the F2 pair tumbling independent of one another.
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Affiliation(s)
- S P Smith
- Department of Biochemistry, University of Oxford, UK
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Kahmann JD, O'Brien R, Werner JM, Heinegârd D, Ladbury JE, Campbell ID, Day AJ. Localization and characterization of the hyaluronan-binding site on the link module from human TSG-6. Structure 2000; 8:763-74. [PMID: 10903951 DOI: 10.1016/s0969-2126(00)00163-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND The interactions of hyaluronan (HA) with proteins are important in extracellular matrix integrity and leukocyte migration and are usually mediated by a domain termed a Link module. Although the tertiary structure of a Link module has been determined, the molecular basis of HA-protein interactions remains poorly understood. RESULTS Isothermal titration calorimetry was used to characterize the interaction of the Link module from human TSG-6 (Link_TSG6) with HA oligosaccharides of defined length (HA(4)-HA(16)). All oligomers bound (except HA(4)) with K(d) values ranging from 0.2-0.5 microM at 25 degrees C. The reaction is exothermic with a favourable entropy and the thermodynamic profile is similar to those of other glycosaminoglycan-protein interactions. The HA(8) recognition site on Link_TSG6 was localized by comparing nuclear magnetic resonance (NMR) spectra from a 1:1 complex with free protein. Residues perturbed on HA binding include both amino acids that are likely to be directly involved in the interaction (i.e., Lys11, Tyr59, Asn67, Phe70, Lys72 and Tyr78) and those affected by a ligand-induced conformational change in the beta4/beta5 loop. The sidechain of Asn67 becomes more rigid in the complex suggesting that it is in close proximity to the binding site. CONCLUSIONS In TSG-6 a single Link module is sufficient for a high-affinity interaction with HA. The HA-binding surface on Link_TSG6 is found in a similar position to that suggested previously for CD44, indicating that its location might be conserved across the Link module superfamily. Here we find no evidence for the involvement of linear sequence motifs in HA binding.
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Affiliation(s)
- J D Kahmann
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
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Hashimoto Y, Smith SP, Pickford AR, Bocquier AA, Campbell ID, Werner JM. The relative orientation of the fibronectin 6F1(1)F2 module pair: a 15N NMR relaxation study. J Biomol NMR 2000; 17:203-214. [PMID: 10959628 DOI: 10.1023/a:1008341609461] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The structure of a pair of modules (6F1(1)F2), that forms part of the collagen-binding region of fibronectin, is refined using heteronuclear relaxation data. A structure of the pair was previously derived from 1H-1H NOE and 3J(HalphaHN) data [Bocquier et al. (1999) Structure, 7, 1451-1460] and a weak module-module interface, comprising Leu19 and Leu28, in 6F1, and Tyr68 in 2F1, was identified. In this study, the definition of the average relative orientation of the two modules is improved using the dependence of 15N relaxation on rotational diffusion anisotropy. This structure refinement is based on the selection of a subset of structures from sets calculated with NOE and 3J(HalphaHN) data alone, using the quality of the fits to the relaxation data as the selection criterion. This simple approach is compared to a refinement strategy where 15N relaxation data are included in the force field as additional restraints [Tjandra et al. (1997) Nat. Struct. Biol., 4, 443-449].
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Affiliation(s)
- Y Hashimoto
- Department of Biochemistry, University of Oxford, UK
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Abstract
Calcium binding (cb) epidermal growth factor-like (EGF) domains are found in a wide variety of extracellular proteins with diverse functions. In several proteins, including the fibrillins (1 and 2), the low-density lipoprotein receptor, the Notch receptor and related molecules, these domains are organised as multiple tandem repeats. The functional importance of calcium-binding by EGF domains has been underscored by the identification of missense mutations associated with defective calcium-binding, which have been linked to human diseases. Here, we present (15)N backbone relaxation data for a pair of cbEGF domains from fibrillin-1, the defective protein in the Marfan syndrome. The data were best fit using a symmetric top model, confirming the extended conformation of the cbEGF domain pair. Our data demonstrate that calcium plays a key role in stabilising the rigidity of the domain pair on the pico- to millisecond time-scale. Strikingly, the most dynamically stable region of the construct is centred about the domain interface. These results provide important insight into the properties of intact fibrillin-1, the consequences of Marfan syndrome causing mutations, and the ultrastructure of fibrillins and other extracellular matrix proteins.
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Affiliation(s)
- J M Werner
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
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13
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Abstract
The transforming growth factor beta (TGF-beta) binding protein-like (TB) domain is found principally in proteins localized to extracellular matrix fibrils, including human fibrillin-1, the defective protein in the Marfan syndrome. Analysis of the nuclear magnetic resonance (NMR) data for the sixth TB module from human fibrillin-1 has revealed the existence of two stable conformers that differ in the isomerization states of two proline residues. Unusually, the two isoforms do not readily interconvert and are stable on the time scale of milliseconds. We have computed independent structures of the major and minor conformers of TB6 to assess how the domain fold adjusts to incorporate alternatively cis- or trans-prolines. Based on previous observations, it has been suggested that multiple conformers can only be accommodated in flexible regions of protein structure. In contrast, P22, which exists in trans in the major form and cis in the minor form of TB6, is in a rigid region of the domain, which is confirmed by backbone dynamics measurements. Overall, the structures of the major and minor conformers are similar. However, the secondary structure topologies of the two forms differ as a direct consequence of the changes in proline conformation.
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Affiliation(s)
- X Yuan
- Department of Biochemistry, University of Oxford, United Kingdom
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Downing AK, Knott V, Werner JM, Cardy CM, Campbell ID, Handford PA. Solution structure of a pair of calcium-binding epidermal growth factor-like domains: implications for the Marfan syndrome and other genetic disorders. Cell 1996; 85:597-605. [PMID: 8653794 DOI: 10.1016/s0092-8674(00)81259-3] [Citation(s) in RCA: 314] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The nuclear magnetic resonance structure of a covalently linked pair of calcium-binding (cb) epidermal growth factor-like (EGF) domains from human fibrillin-1, the protein defective in the Marfan syndrome, is described. The two domains are in a rigid, rod-like arrangement, stabilized by interdomain calcium binding and hydrophobic interactions. We propose a model for the arrangement of fibrillin monomers in microfibrils that reconciles structural and antibody binding data, and we describe a set of disease-causing mutations that provide the first clues to the specificity of cbEFG interactions. The residues involved in stabilizing the domain linkage are highly conserved in fibrillin, fibulin, thrombomodulin, and the low density lipoprotein receptor. We propose that the relative orientation of tandem cbEGF domains in these proteins is similar, but that in others, including Notch, pairs adopt a completely different conformation.
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Affiliation(s)
- A K Downing
- Department of Biochemistry University of Oxford, United Kingdom
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Werner JM, Breeze AL, Kara B, Rosenbrock G, Boyd J, Soffe N, Campbell ID. Secondary structure and backbone dynamics of human granulocyte colony-stimulating factor in solution. Biochemistry 1994; 33:7184-92. [PMID: 7516182 DOI: 10.1021/bi00189a022] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The secondary structure and backbone dynamics of the cytokine, human granulocyte colony-stimulating factor (hG-CSF) have been determined by heteronuclear nuclear magnetic resonance (NMR) techniques. Virtually complete NH, C alpha H, C beta H 15N, 13C alpha, and 13C beta assignment of the 175-residue recombinant protein, methionyl-[Cys-17-Ser]-hG-CSF, was achieved by use of three-dimensional (3D) heteronuclear 1H-15N and triple-resonance 1H-15N-13C experiments. Spectra recorded at 750 MHz aided the assignment of severely overlapped regions. The structures of G-CSF from several species have recently been determined by X-ray diffraction [Hill, C. P., Osslund, T. D., & Eisenberg, D. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 5167-5171; Lovejoy, B., Cascio, D., & Eisenberg, D. (1993) J. Mol. Biol. 234, 640-653]. Like several cytokines, hG-CSF has a four-helix topology (A-D) with overhand loop connections, but with an additional helical segment (A') identified in the connection between helix A and helix B. The solution-state determination of the secondary structure is based on short- and medium-range NOEs, backbone J-couplings, and NH exchange data and is corroborated by 13C alpha secondary shifts. The helices are defined as follows: A, 10-38; A',44-53; B, 71-91; C, 102-123; D, 143-172. The dynamics of the amide backbone resonances, investigated using 1H-15N heteronuclear NMR, indicate a rigid protein core with some increased mobility in the AB loop and more pronounced mobility in the CD loop.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J M Werner
- Department of Biochemistry, University of Oxford, U.K
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Abstract
A quasi-experimental non-equivalent control group design was used to assess the influence of a two-day experiential alcohol education package for non-specialist health care and social workers. Four pairs of teams took part in the study: general practice; accident and emergency; medicine for the elderly; and social work. The dual foci of the evaluation were agents' knowledge and attitudes, and these were assessed using a modified version of the Alcohol and Alcohol Problems Perception Questionnaire (AAPPQ). For both variables, the one-month follow-up scores of the education teams were significantly higher than those of the comparisons, although the effect was stronger in the case of therapeutic attitudes than knowledge. There were also significant differences in improvement in attitude scores, with significant effects being observed in the general practice, medicine for the elderly and social work teams but not the accident and emergency. At 6 months, the level of fall-off in improvement varied and this, along with the pattern of change evident in the five components which comprise the AAPPQ attitude scale, was examined and discussed in relation to previous research in this field of inquiry.
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Affiliation(s)
- D M Gorman
- Drinking Problem Service, Brookfields Hospital, Cambridge, United Kingdom
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Werner JM, Morris A. A recommendation for prevention of alcohol related disorders. J Public Health (Oxf) 1981. [DOI: 10.1093/oxfordjournals.pubmed.a043399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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