Thioredoxin and glutaredoxin regulate metabolism through different multiplex thiol switches

The aim of the present study was to define the role of Trx and Grx on metabolic thiol redox regulation and identify their protein and metabolite targets. The hepatocarcinoma-derived HepG2 cell line under both normal and oxidative/nitrosative conditions by overexpression of NO synthase (NOS3) was used as experimental model. Grx1 or Trx1 silencing caused conspicuous changes in the redox proteome reflected by significant changes in the reduced/oxidized ratios of specific Cys's including several glycolytic enzymes. Cys⁹¹ of peroxiredoxin-6 (PRDX6) and Cys¹⁵³ of phosphoglycerate mutase-1 (PGAM1), that are known to be involved in progression of tumor growth, are reported here for the first time as specific targets of Grx1. A group of proteins increased their Cys_RED/Cys_OX ratio upon Trx1 and/or Grx1 silencing, including caspase-3 Cys¹⁶³, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) Cys²⁴⁷ and triose-phosphate isomerase (TPI) Cys²⁵⁵ likely by enhancement of NOS3 auto-oxidation. The activities of several glycolytic enzymes were also significantly affected. Glycolysis metabolic flux increased upon Trx1 silencing, whereas silencing of Grx1 had the opposite effect. Diversion of metabolic fluxes toward synthesis of fatty acids and phospholipids was observed in siRNA-Grx1 treated cells, while siRNA-Trx1 treated cells showed elevated levels of various sphingomyelins and ceramides and signs of increased protein degradation. Glutathione synthesis was stimulated by both treatments. These data indicate that Trx and Grx have both, common and specific protein Cys redox targets and that down regulation of either redoxin has markedly different metabolic outcomes. They reflect the delicate sensitivity of redox equilibrium to changes in any of the elements involved and the difficulty of forecasting metabolic responses to redox environmental changes.

•

Trx1 and Grx1 Cys redox targets are abundant among Glycolytic enzymes.

•

PRDX6-Cys⁹¹ and PGAM-Cys¹⁵³ are specific targets of Grx1.

•

Down regulation of thioredoxin and glutaredoxin have different metabolic outcomes.

•

Glutathione synthesis and membrane lipid composition are sensitive to Trx1 and Grx1 down regulation.

•

Redoxins down regulation also induce target Cys reductive changes under NOS3 overexpression.

Restless legs syndrome in patients with chronic venous disorders: an untold story

Objectives: To prospectively study the profile of restless leg syndrome (RLS) in patients presenting to a phlebology practice.

Methods: The study uses prospective questionnaire and clinical observation study. In all, 174 consecutive patients and 174 matched controls were evaluated in detail. The diagnosis of restless legs syndrome (RLS) was established by the International RLS study group (IRLSSG) criteria. Detailed clinical, systemic and Duplex ultrasound evaluations were done to establish the presence of chronic venous disorders (CVD) (reflux > 0.5s on augmentation manoeuvers and revised clinical, aetiological, anatomical and pathological [CEAP] criteria).

Results: Of the 174 consecutive subjects studied (22M: 152F), 63 (36%) had evidence of RLS compared with only 34 of 174 of the controls (19%, P <0.05). Sixty-two (98%) of these RLS-positive study subjects were subsequently diagnosed with CVD. In comparison, 31 (91%) of the RLS-positive control subjects ( n = 34) were found to have CVD. This prevalence of CVD was comparable with RLS-positive study subjects, but was significantly higher than the prevalence in CVD in RLS-negative controls ( P <0.01). Only three (9%) of the controls had RLS without CVD. RLS-positive subjects were typically women above the age of 40 years ( P <0.01 vs. men, P <0.01 vs. below 40 years). A significant difference in clinical presentation in the study subjects was the high prevalence of leg cramps in the RLS-positive subjects ( P <0.01). None of the patients with RLS in this series gave history of anaemia, chronic renal failure or an established psychiatric or neurological disease as found pathognomic for RLS by others.

Conclusions: RLS appears to be a common overlapping clinical syndrome in patients with CVD. Prospective blinded therapeutic trials are planned to study the influence of definitive treatments for CVD on sequential RLS scores.

Clinical spectrum of recurrent postoperative varicose veins and efficacy of sclerotherapy management using the compass technique

Objectives: Tostudy the clinical spectrum of recurrent varices after surgery (REVAS) and the efficacy of sclerotherapy under the comprehensive objective mapping, precise image-guided injection, antireflux positioning and sequential sclerotherapy (COMPASS) technique in their management.

Methods: Design: prospective open study with 1.5-5.7-year follow up. Patients: 253 legs of 168 consecutive patients who had received previous surgery for primary varicosity.

Main outcome measures: obliteration, recanalization, residual reflux, neovascularization, venous dysfunction score and cumulative obliteration.

Results: REVAS presents as a symptomatic chronic venous disease of women in their fifties, a decade later than primary varicosities are reported. Almost 75% of REVAS occurred at the groin, mostly with features of chronic venous disease. The COMPASS technique achieved sustained obliteration in 97% of the groin varices and in 100% of the thigh and isolated refluxes around the popliteal fossa. The cumulative obliteration rate was sustained at >90% and obliteration of perforator reflux was sustained. There was a significant decrease in the venous dysfunction score. In the mean 3.1±1.7 years of follow up, only 3% possible neovascularization was seen. There were no serious adverse experiences reported.

Conclusions: REVAS is a symptomatic chronic venous disease requiring skilled medical attention. The COMPASS technique appears to be more efficacious than the presently available surgical approaches to its long-term management.

Management of venous malformations in Klippel–Trenaunay syndrome with ultrasound-guided foam sclerotherapy

Objective: To study the clinical profile of Klippel–Trenaunay syndrome (KTS) and the management of venous malformations (VMs) with ultrasound-guided foam sclerotherapy using the compass technique.

Methods: In this open prospective series, 11 consecutive patients with KTS seeking therapy at a phlebology group practice were included. Seven (64%) of them were post-surgical recurrences.

Results: Pain was the commonest presenting complaint (100%), accompanied with VMs/ varicose veins in all except one (91%). Chronic venous insufficiency (CVI) was seen in seven (64%). Soft tissue and bone deformity was present in all (100%). Limb lengthening was frequent and detected in eight (73%), thickening in six (54%); unusually, one patient (9%) presented with severe thinning and shortening of the leg. Venous malformation was the primary vascular problem in nine patients (82%), with capillary malformation (CM)/port wine stain in seven (64%) and isolated lymphatic malformation (LM) in two (18%). The lateral embryonic/Klippel–Trenaunay (KT) vein was detected in 10 patients (91%). Deep vein deformity was not detected in any of them. All the deformities were of the lower limb (100%), while two (18%) had deformities of the thorax and one (9%) had gastrointestinal (GI) malformation. None of the patients gave family history of KTS, while five (45%) had history of varicosities in the family. Eight patients (73%) completed the therapeutic plan with a mean follow-up of 5±3.9 years. An excellent to good type result could be documented in six of the eight cases (75%). These patients had an event-free, good quality of life. Follow-up duplex studies revealed the evolving refluxing tracts requiring sequential therapies.

Conclusions: The results in this series demonstrate the utility of foam sclerotherapy using the compass technique in the management of KTS. Chronicity of the VMs in KTS necessitates strict clinical monitoring and sequential therapies.

Efficacy of the Comprehensive Objective Mapping, Precise Image Guided Injection, Anti-Reflux Positioning and Sequential Sclerotherapy (COMPASS) Technique in the Management of Greater Saphenous Varicosities with Saphenofemoral Incompetence

Objective:

To evaluate the efficacy of the COMPASS technique in the management of greater saphenous varicosities with saphenofemoral incompetence.

Design:

Prospective open trial (2-6 year follow-up).

Patients:

One hundred and eighty-six limbs with refluxing greater saphenous vein (5.4–25.4 mm) and incompetent saphenofemoral junction (6.1–31.3 mm).

Main outcome measure:

Obliteration, recanalisation, residual veins, neovascularisation, venous dysfunction score.

Results:

Greater saphenous varicosity is commonly a disease of individuals in their forties, with morbid clinical presentations. Three stages of the COMPASS technique achieved 100% and 98% obliteration of the saphenofemoral junction and greater saphenous vein respectively. There was significant improvement in the venous dysfunction score. Residual refluxing veins were easily managed by sequential treatment. The results are sustained in the 3.4 SD 1.7 year follow up. There was no serious adverse experience reported.

Conclusion:

The COMPASS technique is safe and highly efficacious in the management of extensive large vein varicose disease.

Effects of oxidative stress on protein thiols and disulphides in Mytilus edulis revealed by proteomics: actin and protein disulphide isomerase are redox targets

Many proteins contain cysteines which are sensitive to oxidation. This is sometimes reversible through interaction with glutathione, glutaredoxin or thioredoxin systems making these proteins potential sensors of oxidative stress. In this study we analysed whether there was an increase in mixed disulphide bond (-S-S-) formation in the blue mussel Mytilus edulis in response to menadione. This was achieved by initially blocking reduced thiols with N-ethylmaleimide, -S-S- were then reduced with dithiothreitol (DTT) and labelled with 5-iodoacetamidofluorescein (5-IAF). Free -SHs were also labelled directly with 5-IAF. Separations were performed on 1D or 2D SDS PAGE and images analysed. There was an increase in -S-S- in response to menadione and detection of changes in oxidised proteins was easier than that of changes in the amount of reduced proteins. Protein disulphide isomerase (PDI) was labelled both as -SH and -S-S-, underlining its involvement in the redox status of the animal. A glutathione transferase (GST P1-1) forms an inter-chain disulphide bridge in response to menadione.

Redox proteomics in the mussel, Mytilus edulis

Pollutants (e.g. PAHs, metals) cause oxidative stress (OS) by forming reactive oxygen species. Redox proteomics provides a means for identifying protein-specific OS effects in Mytilus edulis. Groups of mussels were sampled from a clean site in Cork Harbour, Ireland and exposed to 1 mM H2O2 in holding tanks. Protein extracts of gill and digestive gland were separated by two dimensional electrophoresis and similar protein expression profiles were found. Effects of OS on disulphide bridge patterns were investigated in diagonal gels by separating proteins in non-reducing conditions followed by a second reducing dimension. Immunoprecipitation selected carbonylated and glutathionylated proteins. These methodologies can contribute to redox proteomic studies of pollutant responses in marine organisms.

Binge eating disorder in extreme obesity

OBJECTIVE

To determine whether extremely obese binge eating disorder (BED) subjects (BED defined by the Eating Disorder Examination) differ from their extremely obese non-BED counterparts in terms of their eating disturbances, psychiatric morbidity and health status.

DESIGN

Prospective clinical comparison of BED and non-BED subjects undergoing gastric bypass surgery (GBP).

SUBJECTS

Thirty seven extremely obese (defined as BMI > or = 40 kg/m(2)) subjects (31 women, six men), aged 22-58 y.

MEASUREMENTS

Eating Disorder Examination 12th Edition (EDE), Three Factor Eating Questionnaire (TFEQ), Structured Clinical Interview for the Diagnostic and Statistical Manual-IV (SCID-IV), Short-Form Health Status Survey (SF-36), and 24 h Feeding Paradigm.

RESULTS

Twenty-five percent of subjects were classified as BED (11% met full and 14% partial BED criteria) and 75% of subjects were classified as non-BED. BED (full and partial) subjects had higher eating disturbance in terms of eating concern and shape concern (as found by the EDE), higher disinhibition (as found by the TFEQ), and they consumed more liquid meal during the 24 h feeding paradigm. No difference was found in psychiatric morbidity between BED and non-BED in terms of DSM-IV Axis I diagnosis. The health status scores of both BED and non-BED subjects were significantly lower than US norms on all subscales of the SF-36, particularly the BED group.

CONCLUSION

Our findings support the validity of the category of BED within a population of extremely obese individuals before undergoing GBP. BED subjects differed from their non-BED counterparts in that they had a greater disturbance in eating attitudes and behavior, a poorer physical and mental health status, and a suggestion of impaired hunger/satiety control. However, in this population of extremely obese subjects, the stability of BED warrants further study.

Cognitive therapy, nutritional therapy and their combination in the treatment of bulimia nervosa

BACKGROUND

This study compared the effectiveness of cognitive therapy (CT), nutritional therapy (NT), the combination of cognitive and nutritional therapy (CNT), against a control condition of support group (SG) in the treatment of bulimia nervosa.

METHODS

One hundred female out-patients who fulfilled DSM-III-R criteria for bulimia nervosa were randomized to the four treatment groups. NT and CT were designed to cover different areas with minimal overlap, and CNT provided all of the features of both of these treatments. The control condition was conducted in a group self-help format. Each of the treatments lasted 14 weeks.

RESULTS

All three active treatments as well as SG produced significant decreases in binge/vomit episodes. Intent-to-treat analysis found CNT and CT to be significantly more effective than SG in retaining subjects in treatment and completion of study, as well as in producing greater improvements in dysfunctional attitudes and self-control. CNT was superior to SG in achieving abstinence from bulimic behaviour. NT was superior to SG only in increase of self-control. Logistic regression found that the cognitive component, whether given alone or in conjunction with NT, and higher pre-treatment self-control scores were significant predictors for both completion of study and abstinence.

CONCLUSION

CT (either alone, or in combination with nutritional therapy) remains the treatment of choice for bulimia nervosa. A treatment escalation approach should be tested for the treatment of bulimia with the more intensive and less widely available CT (with or without nutritional counselling) offered after patients have failed the less intensive and more widely available support group treatment.