SNARE chaperone Sly1 directly mediates close-range vesicle tethering

The essential Golgi protein Sly1 is a member of the Sec1/mammalian Unc-18 (SM) family of SNARE chaperones. Sly1 was originally identified through remarkable gain-of-function alleles that bypass requirements for diverse vesicle tethering factors. Employing genetic analyses and chemically defined reconstitutions of ER-Golgi fusion, we discovered that a loop conserved among Sly1 family members is not only autoinhibitory but also acts as a positive effector. An amphipathic lipid packing sensor (ALPS)-like helix within the loop directly binds high-curvature membranes. Membrane binding is required for relief of Sly1 autoinhibition and also allows Sly1 to directly tether incoming vesicles to the Qa-SNARE on the target organelle. The SLY1-20 mutation bypasses requirements for diverse tethering factors but loses this ability if the tethering activity is impaired. We propose that long-range tethers, including Golgins and multisubunit tethering complexes, hand off vesicles to Sly1, which then tethers at close range to initiate trans-SNARE complex assembly and fusion in the early secretory pathway.

Patophysiologic and gender differences regarding exercise responses in decompensated heart failure patients

Funding Acknowledgements

Type of funding sources: None.

Introduction

Heart Failure patients often present impairment on their functional capacity. Exercise training is the key component of cardiac rehabilitation and must be early implemented. Knowing the characteristics that lead a patient to be a good responder to an exercise intervention would be useful to identify the ones that could benefit from this same intervention.

Purpose

Identify the characteristics of good responses to an aerobic exercise training in decompensated heart failure (HF) patients and understand if there are gender differences. 

Methods

Cross sectional study with 76 inpatients who performed an aerobic exercise training program (AET). Functional capacity was evaluated at admission and discharge using three different tools: the London Chest of Activity of Daily Living (LCADL) scale, the Barthel Index (BI) and the 6-minute walking test (6MWT). Multivariate linear regression was performed by gender to understand which variables lead a patient to have better performance. Since it is known that men and women have different responses to exercise training, the results and analysis of the data collected were performed by gender.

Results

Seventy-six patients (52 men) were included. The mean age was 67 ± 10 years, 15.8% were New York Heart Association (NYHA) class IV and 76.3% had reduced ejection fraction. The major etiology of HF was ischemic disease (35.5%). Six predictive equations were obtained, one for each functional capacity (FC) tool divided by gender. NYHA class III patients do not differ from class IV in terms of FC at discharge. However, HFreduced ejection fraction patients presented higher 6MWT distance (309,6m vs 231m) and lower LCADL score (11 vs 15) compared to non-reduced. Gender analysis showed that women had an average of 4 days longer in-hospital stay and a considerable difference in the 6MWT. At admission women walked 15 meters less than man and at discharge 69 meters less, presenting also lower score at BI and higher at LCADL. However, only the discharge 6MWT distance presents a statistical significant difference (69 meters; p = 0.01). Traditionally women are more sedentary and present less fitness level than men. The linear regression model shows that gender is a independent variable that contributes to the change in the 6MWT - favouring men. 

Conclusions

The AET program appears to be more effective in younger patients, with low FC at admission and who are less impaired. Those with left systolic ventricular function apparently interfered with progression during the program. Gender influences the performance of patients undergoing exercise training. Men present higher FC at discharge but the predictive models are stronger for women. These results are consistent with the idea that gender plays an important role in determine the performance of patients in exercise training programs.

Heart failure inpatient"s self-care behaviour: mulricenter approach focousing on gender differences

Funding Acknowledgements

Type of funding sources: None.

Introduction

Heart failure is often characterized by low exercise capacity and great impairment on performance in activities of daily living. The correct management of the disease can prevent the worsening of symptoms and promote a better quality of life. Self-care behaviour plays an important role on patient"s quality of life.

Aim

The aims of this study are to evaluate the self-care behaviour in a sample of heart failure inpatients, using the Self-Care Heart Failure Index (SCHFI) and to understand whether gender and patophisiologic characteristics does interfere on it.

Methods

Cross-sectional multicenter study enrolling 225 heart failure inpatients from eight hospitals. At admission, patient’s functional capacity was evaluated as well as their self-care behaviour, using the SCHFI Portuguese v6.2. Comparison between self-care behaviour with gender was performed. Also some correaltions were perfomed with the total sample of patients, aiming to understand which were the variables that may interfere with the socre of each sub-scale of the self-care HF index. 

Results

Patients’ mean age was 68.4 ± 10.7 years old, 68% were male and 82.3% have reduced ejection fraction. A mean value of 47.9, 35.6 and 38.8 points was found in the SCHFI score of the sections self-care maintenance (SCMt), self-care management (SCMg) and self-care confidence (SCC), respectively. Heart failure inpatients present inadequate levels of self-care behaviour. No difference was found between genders on any section of the SCHFI. Among all variables, only the number of CVRFs and the left ventricular ejection fraction had significant differences. Males had better results, but not with a statistically significant difference. Association tests (ANOVA) between different variables and the score of each section of the SCHFI were perfomred. Only in the NYHA there are variables associated with a better self-care, namely in the SCMg (p = 0.011) and in SCC (p = 0.010). Correlations were made using the numeric variables age, CVRF, BI, LCADL, SCMt, SCMg and SCC, in order to understand the influence of the variables with each other. All the three dimesnions present a positive correlation, at 99% confidence interval between them (SCMt with SCMg: r = 0.365, p < 0.000; SCMt with SCC: r = 0.272, p < 0.000 and SCMg with SCC: r = 0.670, p < 0.000). In addition, SCMt presents a positive correlation with age at a 95% confidence interval (r = 0.158, p = 0.018). Negative correlations were found between 1) BI and age (r=-0.151, p = 0.023), at a 95% confidence interval and 2) BI with LCALD (r=-0.407, p < 0.000), at a 99% confidence interval. Regarding NYHA functional class and left ventricular systolic function, only NYHA class II patients present a statistically significant difference in SCMg and SCC comparing to Class III and IV patients (who do not present differences between them). 

Conclusion

The results do not suggest a relationship between gender and pathophysiological characteristics with self-care behaviour.