Characterization of the 1st and 2nd EF-hands of NADPH oxidase 5 by fluorescence, isothermal titration calorimetry, and circular dichroism

<p>Abstract</p> <p>Background</p> <p>Superoxide generated by non-phagocytic NADPH oxidases (NOXs) is of growing importance for physiology and pathobiology. The calcium binding domain (CaBD) of NOX5 contains four EF-hands, each binding one calcium ion. To better understand the metal binding properties of the 1^stand 2^ndEF-hands, we characterized the N-terminal half of CaBD (NCaBD) and its calcium-binding knockout mutants.</p> <p>Results</p> <p>The isothermal titration calorimetry measurement for NCaBD reveals that the calcium binding of two EF-hands are loosely associated with each other and can be treated as independent binding events. However, the Ca²⁺binding studies on NCaBD(E31Q) and NCaBD(E63Q) showed their binding constants to be 6.5 × 10⁵and 5.0 × 10²M^-1with ΔHs of -14 and -4 kJ/mol, respectively, suggesting that intrinsic calcium binding for the 1^stnon-canonical EF-hand is largely enhanced by the binding of Ca²⁺to the 2^ndcanonical EF-hand. The fluorescence quenching and CD spectra support a conformational change upon Ca²⁺binding, which changes Trp residues toward a more non-polar and exposed environment and also increases its α-helix secondary structure content. All measurements exclude Mg²⁺-binding in NCaBD.</p> <p>Conclusions</p> <p>We demonstrated that the 1^stnon-canonical EF-hand of NOX5 has very weak Ca²⁺binding affinity compared with the 2^ndcanonical EF-hand. Both EF-hands interact with each other in a cooperative manner to enhance their Ca²⁺binding affinity. Our characterization reveals that the two EF-hands in the N-terminal NOX5 are Ca²⁺specific.</p> <p>Graphical abstract</p> <p><display-formula><graphic file="1752-153X-6-29-i1.gif"/></display-formula></p

Integrated Exposure Therapy and Exercise Reduces Fear of Falling and Avoidance in Older Adults: A Randomized Pilot Study.

OBJECTIVES:To evaluate the safety and acceptability of a novel 8-week intervention integrating exercise, exposure therapy, cognitive restructuring, and a home safety evaluation, conducted by a physical therapist, in reducing fear of falling and activity avoidance. To collect preliminary evidence of efficacy. DESIGN:Randomized pilot study comparing the intervention to time- and attention-equivalent fall prevention education. SETTING:Participants' homes. PARTICIPANTS:42 older adults with disproportionate fear of falling (high fear, low to moderate objective fall risk). MEASUREMENTS:Falls Efficacy Scale-International, modified Activity Card Sort, satisfaction, falls. RESULTS:Relative to education, the intervention reduced fear of falling (d = 1.23) and activity avoidance (d = 1.02) at 8 weeks, but effects eroded over a 6-month follow-up period. The intervention did not increase falls, and participants rated the exercise, exposure therapy, and non-specific elements as most helpful. CONCLUSIONS:An integration of exercise and exposure therapy may help older adults with disproportionate fear of falling, but modifications to the intervention or its duration may be needed to maintain participants' gains

Integrated Exposure Therapy and Exercise Reduces Fear of Falling and Avoidance in Older Adults: A Randomized Pilot Study

OBJECTIVES: To evaluate the safety and acceptability of a novel 8-week intervention integrating exercise, exposure therapy, cognitive restructuring, and a home safety evaluation, conducted by a physical therapist, in reducing fear of falling and activity avoidance. To collect preliminary evidence of efficacy. DESIGN: Randomized pilot study comparing the intervention to time- and attention-equivalent fall prevention education. SETTING: Participants\u27 homes. PARTICIPANTS: 42 older adults with disproportionate fear of falling (high fear, low to moderate objective fall risk). MEASUREMENTS: Falls Efficacy Scale-International, modified Activity Card Sort, satisfaction, falls. RESULTS: Relative to education, the intervention reduced fear of falling (d = 1.23) and activity avoidance (d = 1.02) at 8 weeks, but effects eroded over a 6-month follow-up period. The intervention did not increase falls, and participants rated the exercise, exposure therapy, and non-specific elements as most helpful. CONCLUSIONS: An integration of exercise and exposure therapy may help older adults with disproportionate fear of falling, but modifications to the intervention or its duration may be needed to maintain participants\u27 gains

Activity, balance, learning, and exposure (ABLE): a new intervention for fear of falling.

ObjectiveFear of falling is an important problem among older adults, even those with relatively low rates of objective fall risk, who are often overlooked as targets for intervention.MethodWe developed and pilot tested a new intervention, Activity, Balance, Learning, and Exposure (ABLE), in a sample of 10 older adults with excessive fear of falling. The ABLE intervention integrates exposure therapy and cognitive restructuring with a home safety evaluation and an exercise program and is conducted in the home. In this pilot project, ABLE was jointly conducted by a physical therapist and a psychologist with expertise in geriatric anxiety disorders.ResultsThe intervention was feasible and acceptable and resulted in decreases in fear and activity avoidance for most participants. One participant experienced an injurious fall.DiscussionWe learned a number of important lessons resulting in modifications to the inclusion criteria, assessments, and intervention over the course of this pilot study. Results suggest that ABLE has promise for treating excessive fear of falling in the elderly and support testing the intervention in a larger randomized trial. Copyright © 2016 John Wiley &amp; Sons, Ltd