Phospholipid dependency of membrane protein insertion by the Sec translocon

Membrane protein insertion into and translocation across the bacterial cytoplasmic membrane are essential processes facilitated by the Sec translocon. Membrane insertion occurs co-translationally whereby the ribosome nascent chain is targeted to the translocon via signal recognition particle and its receptor FtsY. The phospholipid dependence of membrane protein insertion has remained mostly unknown. Here we assessed in vitro the dependence of the SecA independent insertion of the mannitol permease MtlA into the membrane on the main phospholipid species present in Escherichia coli. We observed that insertion depends on the presence of phosphatidylglycerol and is due to the anionic nature of the polar headgroup, while insertion is stimulated by the zwitterionic phosphatidylethanolamine. We found an optimal insertion efficiency at about 30 mol% DOPG and 50 mol% DOPE which approaches the bulk membrane phospholipid composition of E. coli.</p

Phospholipid dependency of membrane protein insertion by the Sec translocon

Membrane protein insertion into and translocation across the bacterial cytoplasmic membrane are essential processes facilitated by the Sec translocon. Membrane insertion occurs co-translationally whereby the ribosome nascent chain is targeted to the translocon via signal recognition particle and its receptor FtsY. The phospholipid dependence of membrane protein insertion has remained mostly unknown. Here we assessed in vitro the dependence of the SecA independent insertion of the mannitol permease MtlA into the membrane on the main phospholipid species present in Escherichia coli. We observed that insertion depends on the presence of phosphatidylglycerol and is due to the anionic nature of the polar headgroup, while insertion is stimulated by the zwitterionic phosphatidylethanolamine. We found an optimal insertion efficiency at about 30 mol% DOPG and 50 mol% DOPE which approaches the bulk membrane phospholipid composition of E. coli.</p

Cardiac rehabilitation for patients with obesity:lessons learned from the OPTICARE XL trial

Obesity is a known and commonly encountered risk factor for the development of cardiac diseases. Patients with cardiac diseases who also have obesity do not benefit optimally from standard cardiac rehabilitation (CR) programs. Exercises performed during CR are not the best fit for patients with obesity and counselling sessions often do not address their specific needs. OPTICARE XL is the first large multicentre randomised controlled trial to investigate the added value of a dedicated one-year CR program specifically designed for patients with obesity and integrated in daily practice. The short-term effects on body weight and physical activity were promising and patients with obesity experienced the program as highly desirable. However, the OPTICARE XL CR program did not show long-term added value compared with standard CR on health-related quality of life, psychosocial well-being, body weight, physical activity and physical fitness, nor on costs. The current article offers an overview of the background of this trial and discusses the most important results of the OPTICARE XL trial and the reasons behind the unanticipated long-term outcomes. Furthermore, it offers recommendations for future research and how to redesign the OPTICARE XL CR program to expand the short-term results.</p

Cardiac rehabilitation for patients with obesity:lessons learned from the OPTICARE XL trial

Obesity is a known and commonly encountered risk factor for the development of cardiac diseases. Patients with cardiac diseases who also have obesity do not benefit optimally from standard cardiac rehabilitation (CR) programs. Exercises performed during CR are not the best fit for patients with obesity and counselling sessions often do not address their specific needs. OPTICARE XL is the first large multicentre randomised controlled trial to investigate the added value of a dedicated one-year CR program specifically designed for patients with obesity and integrated in daily practice. The short-term effects on body weight and physical activity were promising and patients with obesity experienced the program as highly desirable. However, the OPTICARE XL CR program did not show long-term added value compared with standard CR on health-related quality of life, psychosocial well-being, body weight, physical activity and physical fitness, nor on costs. The current article offers an overview of the background of this trial and discusses the most important results of the OPTICARE XL trial and the reasons behind the unanticipated long-term outcomes. Furthermore, it offers recommendations for future research and how to redesign the OPTICARE XL CR program to expand the short-term results.</p

Health-related quality of life and cardiac rehabilitation: Does body mass index matter?

OBJECTIVE: To investigate the relation between body mass index class and changes in health-related quality of life in patients participating in cardiac rehabilitation. DESIGN: Prospective cohort study. PATIENTS: A total of 503 patients with acute coronary syndrome. METHODS: Data from the OPTICARE trial were used, in which health-related quality of life was measured with the MacNew Heart Disease HRQOL Instrument at the start, directly after, and 9 months after completion of cardiac rehabilitation. Patients were classed as normal weight, overweight, or obese. RESULTS: During cardiac rehabilitation, global health-related quality of life improved in patients in all classes of body mass index. Patients classed as overweight had a significantly greater improvement in social participation than those classed as normal weight (5.51-6.02 compared with 5.73-5.93, respectively; difference in change 0.30, p = 0.025). After completion of cardiac rehabilitation, health-related quality of life continued to improve similarly in patients in all classes of body mass index. CONCLUSION: Health-related quality of life improved during cardiac rehabilitation in patients of all classes of body mass index. Patients classed as overweight showed the greatest improvement. The beneficial effects were maintained during extended follow-up after completion of cardiac rehabilitation

Effects of a Dedicated Cardiac Rehabilitation Program for Patients With Obesity on Body Weight, Physical Activity, Sedentary Behavior, and Physical Fitness:The OPTICARE XL Randomized Controlled Trial

OBJECTIVE: Previously published results of the OPTICARE XL open label randomized controlled trial showed no added value of OPTICARE XL CR, a dedicated cardiac rehabilitation (CR) program for patients with obesity, with respect to health-related quality of life (primary outcome). This clinical trial studied the effects of OPTICARE XL CR on several secondary outcomes, which included body weight, physical activity, sedentary behavior, and physical fitness. METHODS: Patients with coronary artery disease or atrial fibrillation and body mass index ≥ 30 were randomized to OPTICARE XL CR (n = 102) or standard CR (n = 99). OPTICARE XL CR was a 1-year group intervention, specifically designed for patients with obesity that included aerobic and strength exercise, behavioral coaching, and an aftercare program. Standard CR consisted of a 6- to 12-week group aerobic exercise program, supplemented with cardiovascular lifestyle education. Study end points included body weight, physical activity, sedentary behavior (accelerometer), and physical fitness (6-Minute Walk Test and handgrip strength), which were evaluated 6 months after the end of CR (primary endpoint) and 3 months after the start of CR. RESULTS: Six months after completion of either program, improvements in body weight, physical activity, sedentary behavior, and physical fitness were similar between the groups. Three months after CR start, patients randomized to OPTICARE XL CR showed greater weight loss (mean change = -3.6 vs -1.8 kg) and a larger improvement in physical activity (+880 vs +481 steps per day) than patients randomized to standard CR. CONCLUSION: Patients allocated to OPTICARE XL CR lost significantly more body weight and showed promising results with respect to physical activity 3 months after the start of CR; however, these short-term results were not expanded or sustained in the longer term. IMPACT: Patients with obesity do not benefit from standard CR programs. The new OPTICARE XL CR program showed its effects in the short term on weight loss and physical activity, and, therefore, redesign of the aftercare phase is recommended.</p

Heart failure and promotion of physical activity before and after cardiac rehabilitation (HF-aPProACH):a study protocol

Abstract Aims Lifestyle changes, such as increasing physical activity (PA), are a cornerstone of treatment of patients with chronic heart failure (HF). However, improving PA in HF patients is challenging, and low participation rates for cardiac rehabilitation (CR) as well as relapse to low PA levels after CR are major issues. We designed a randomized controlled trial to investigate if PA monitoring with motivational feedback before and after centre‐based CR in HF patients with reduced ejection fraction (HFrEF) will lead to a clinically meaningful increase in physical fitness. Methods and results A randomized controlled trial will be conducted in a sample of 180 HFrEF patients (New York Heart Association Class II/III) who are referred to 12‐week standard CR. Patients will be randomized (2:1) to (1) standard of care (SoC) plus wearing a PA monitoring device (Fitbit Charge 3) with personalized step goals, feedback and motivation or (2) SoC only. The intervention lasts ±7 months: 4–5 weeks before CR, 12 weeks during CR and 12 weeks after CR. Measurements will take place at three time points. The primary endpoint is the change in the distance in 6‐min walking test (6MWT) over the entire study period. Other endpoints include step count, grip strength, quality of life and all‐cause mortality or hospitalization. Conclusions HF‐aPProACH will provide novel information on the effectiveness of remote PA stimulation and feedback before, during and after standard CR using a commercially available device to improve physical fitness in HFrEF patients

Pull-out and push-in tests of bonded steel strands

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