Provocation of delayed-onset muscle soreness in the human jaw-closing muscles

Kemal S. Türker, Michail Koutris, N. Ceren Sümer, E. Sibel Atış, Ian R. Linke, Frank Lobbezoo and Machiel Naeijehttp://www.elsevier.com/wps/find/journaldescription.cws_home/203/description#descriptio

Crystal structure of Schistosoma mansoni Peroxiredoxin I: insights into a general mechanism of assembly of stress-regulated chaperones

2-Cys peroxiredoxins (Prx) are thought to play two alternative roles in cell's physiology: under low oxidative stress they are thioredoxin-dependent peroxidases, whereas upon exposure to high concentrations of H2O2, they change their oligomerization state from low molecular weight form (LMW) to high molecular weight (HMW) ATP-independent chaperones. Neither the precise structure of HMW complexes nor the binding site for unfolded proteins has been yet identified. In this poster we present the 3D crystal structures of decameric, LMW form, of PrxI from Schistosoma mansoni, obtained under reducing conditions and neutral pH, and of its HMW form, obtained under non-reducing conditions and acidic pH. The HMW is constituted by two stacked decamers. Size exclusion chromatography and functional experiments confirmed that the former has peroxidase activity whereas the latter is the putative holdase. Analysing the structures and using computational methods, we were able to explain the stacking of decamers (and thereby the switch between LMW and HMW) in terms of a quaternary change induced by tertiary structural variations occurring at the dimer-dimer interface. We suggest that environmental redox information is transmitted by hierarchical structural transitions that change the function of Prx through overoxidation of the sulphur atom of Cysp and unwinding of the first turn of the a5 helix. This event induces C-terminal arm unfolding and the concomitant protrusion of a loop towards the nearby dimer, triggering the quaternary structural change at the basis of the formation of the HMW form. Our structures provide also a model by which members of the Prx protein family form long filaments of stacked rings in vivo and enables us to propose how the HMW forms acquire the capability to bind non-native proteins

Moonlighting by Different Stressors Crystal Structure of the Chaperone Species of a 2 Cys Peroxiredoxin

2-Cys peroxiredoxins (Prxs) play two different roles depending on the physiological status of the cell. They are thioredoxin-dependent peroxidases under low oxidative stress and ATP-independent chaperones upon exposure to high peroxide concentrations. These alternative functions have been associated with changes in the oligomerization state from low-(LMW) to high-molecular-weight (HMW) species. Here we present the structures of Schistosoma mansoni Prx1 in both states: the LMW decamer and the HMW 20-mer formed by two stacked decamers. The latter is the structure of a 2-Cys Prx chaperonic form. Comparison of the structures sheds light on the mechanism by which chemical stressors, such as high H2O2 concentration and acidic pH, are sensed and translated into a functional switch in this protein family.. We also propose a model to account for the in vivo formation of long filaments of stacked Prx rings

Diagnostic criteria for temporomandibular disorders in children and adolescents: An international Delphi study-Part 2-Development of Axis II

Background: Unlike the psychosocial assessment established for adults in the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), a standardised psychosocial assessment for children and adolescents with TMD complaints has not yet been established. Objectives: To develop a new standardised instrument set to assess the psychosocial functioning in children and adolescents by adapting the psychosocial status and pain-related disability (Axis II) of the adult DC/TMD and by including new instruments. Methods: A modified Delphi method was used to survey 23 international TMD experts and four international experts in pain-related psychological factors for consensus regarding assessment tools for psychosocial functioning and pain-related disability in children and adolescents. The TMD experts reviewed 29 Axis II statements at round 1, 13 at round 2 and 2 at round 3. Agreement was set at 80% for first-round consensus level and 70% for each of the second and third rounds. The psychological experts completed a complementary Delphi survey to reach a consensus on tools to use to assess more complex psychological domains in children and adolescents. For the psychological experts, the first round included 10 open-ended questions on preferred screening tools for depression, anxiety, catastrophising, sleep problems and stress in children (ages 6–9 years old) and adolescents (ages 10–19 years old) as well as on other domains suggested for investigation. In the second round, the psychological experts received a 9-item questionnaire to prioritise the suggested instruments from most to least recommended. Results: The TMD experts, after three Delphi rounds, reached consensus on the changes of DC/TMD to create a form to evaluate Axis II in children and adolescents with TMD complaints. The psychological experts added tools to assess depression and anxiety, sleep disorders, catastrophising, stress and resilience. Conclusion: Through international expert consensus, this study adapted Axis II of the adult DC/TMD to assess psychosocial functioning and pain-related disability in children and adolescents. The adapted Axis II protocols will be validated in the target populations

“Distinct cellular responses induced by saporin and a transferrin-saporin conjugate in two different human glioblastoma cell lines”

"Glioblastoma multiforme (GBM) is the most common primary brain tumour in adults, with a. median survival of ~12-18 months post-diagnosis. GBM usually recurs within 12 months postresection,. with poor prognosis. Thus, novel therapeutic strategies to target and kill GBM cells are. urgently needed. The marked difference of tumour cells with respect to normal brain cells, renders. glioblastoma a good candidate for selective targeted therapies. Recent experimental strategies focus. on over expressed cell surface receptors. Targeted toxins represent a new class of selective. molecules composed by a potent protein toxin and a carrier ligand. Targeted toxins approaches. against glioblastoma were under investigation in phase I and II clinical trials with several. immunotoxins (IT)\/ligand toxins such as IL4-Pseudomonas aeruginosa exotoxin A(IL4-PE, NBI-. 3001), tumour growth factor fused to PE38, a shorter PE variant, (TGF)alpha-TP-38, IL13-PE38,. and a transferrin-C diphtheriae toxin mutant (Tf-CRM107). In this work, we studied the effects of. the plant ribosome–inactivating saporin and of its chimera transferrin-saporin against two different. GBM cell lines. The data obtained here indicate that cell proliferation is affected by the toxin. treatments but that different mechanisms are used, directly linked to the presence of an active or. inactive p53. A model is proposed for these alternate intracellular pathways..

Distinct cellular responses induced by saporin and a trasferrin-saporin conjugate in two different human glioblastoma cell lines

"Glioblastoma multiforme (GBM) is the most common primary brain tumour in adults, with a median survival of ∼12-18 months post-diagnosis. GBM usually recurs within 12 months post-resection, with poor prognosis. Thus, novel therapeutic strategies to target and kill GBM cells are urgently needed. The marked difference of tumour cells with respect to normal brain cells, renders glioblastoma a good candidate for selective targeted therapies. Recent experimental strategies focus on over expressed cell surface receptors. Targeted toxins represent a new class of selective molecules composed by a potent protein toxin and a carrier ligand. Targeted toxins approaches against glioblastoma were under investigation in phase I and II clinical trials with several immunotoxins (IT)\/ligand toxins such as IL4-Pseudomonas aeruginosa exotoxin A(IL4-PE, NBI-3001), tumour growth factor fused to PE38, a shorter PE variant, (TGF)alpha-TP-38, IL13-PE38, and a transferrin-C diphtheriae toxin mutant (Tf-CRM107). In this work, we studied the effects of the plant ribosome-inactivating saporin and of its chimera transferrin-saporin against two different GBM cell lines. The data obtained here indicate that cell proliferation is affected by the toxin treatments but that different mechanisms are used, directly linked to the presence of an active or inactive p53. A model is proposed for these alternate intracellular pathways.

The development of the Standardised Tool for the Assessment of Bruxism (STAB): An international road map

This paper summarises the background reasoning and work that led to the selection of the items included in the Standardised Tool for the Assessment of Bruxism (STAB), also introducing the list of items. The instrument is currently being tested for face validity and on-field comprehension. The underlying premise is that the different motor activities included in the bruxism spectrum (e.g. clenching vs. grinding, with or without teeth contact) potentially need to be discriminated from each other, based on their purportedly different aetiology, comorbidities and potential consequences. Focus should be on a valid impression of the activities' frequency, intensity and duration. The methods that can be used for the above purposes can be grouped into strategies that collect information from the patient's history (subject-based), from the clinical assessment performed by an examiner (clinically based) or from the use of instruments to measure certain outcomes (instrumentally based). The three strategies can apply to all aspects of bruxism (i.e. status, comorbid conditions, aetiology and consequences). The STAB will help gathering information on many aspects, factors and conditions that are currently poorly investigated in the field of bruxism. To this purpose, it is divided into two axes. Axis A includes the self-reported information on bruxism status and potential consequences (subject-based report) together with the clinical (examiner report) and instrumental assessment (technology report). Axis B includes the self-reported information (subject-based report) on factors and conditions that may have an etiological or comorbid role for bruxism. This comprehensive multidimensional assessment system will allow building predictive model for clinical and research purposes

Systematic comparison of single-chain Fv antibody-fusion toxin constructs containing Pseudomonas Exotoxin A or saporin produced in different microbial expression systems.

BACKGROUND: Antibodies raised against selected antigens over-expressed at the cell surface of malignant cells have been chemically conjugated to protein toxin domains to obtain immunotoxins (ITs) able to selectively kill cancer cells. Since latest generation immunotoxins are composed of a toxic domain genetically fused to antibody fragment(s) which confer on the IT target selective specificity, we rescued from the hydridoma 4KB128, a recombinant single-chain variable fragment (scFv) targeting CD22, a marker antigen expressed by B-lineage leukaemias and lymphomas. We constructed several ITs using two enzymatic toxins both able to block protein translation, one of bacterial origin (a truncated version of Pseudomonas exotoxin A, PE40) endowed with EF-2 ADP-ribosylation activity, the other being the plant ribosome-inactivating protein saporin, able to specifically depurinate 23/26/28S ribosomal RNA. PE40 was selected because it has been widely used for the construction of recombinant ITs that have already undergone evaluation in clinical trials. Saporin has also been evaluated clinically and has recently been expressed successfully at high levels in a Pichia pastoris expression system. The aim of the present study was to evaluate optimal microbial expression of various IT formats. RESULTS: An anti-CD22 scFv termed 4KB was obtained which showed the expected binding activity which was also internalized by CD22(+) target cells and was also competed for by the parental monoclonal CD22 antibody. Several fusion constructs were designed and expressed either in E. coli or in Pichia pastoris and the resulting fusion proteins affinity-purified. Protein synthesis inhibition assays were performed on CD22(+) human Daudi cells and showed that the selected ITs were active, having IC50 values (concentration inhibiting protein synthesis by 50% relative to controls) in the nanomolar range. CONCLUSIONS: We undertook a systematic comparison between the performance of the different fusion constructs, with respect to yields in E. coli or P. pastoris expression systems and also with regard to each constructs specific killing efficacy. Our results confirm that E. coli is the system of choice for the expression of recombinant fusion toxins of bacterial origin whereas we further demonstrate that saporin-based ITs are best expressed and recovered from P. pastoris cultures after yeast codon-usage optimization