Characterization of the Relationship between the Chaperone and Lipid-Binding Functions of the 70-kDa Heat-Shock Protein, HspA1A.

HspA1A, a molecular chaperone, translocates to the plasma membrane (PM) of stressed and cancer cells. This translocation results in HspA1A's cell-surface presentation, which renders tumors radiation insensitive. To specifically inhibit the lipid-driven HspA1A's PM translocation and devise new therapeutics it is imperative to characterize the unknown HspA1A's lipid-binding regions and determine the relationship between the chaperone and lipid-binding functions. To elucidate this relationship, we determined the effect of phosphatidylserine (PS)-binding on the secondary structure and chaperone functions of HspA1A. Circular dichroism revealed that binding to PS resulted in minimal modification on HspA1A's secondary structure. Measuring the release of inorganic phosphate revealed that PS-binding had no effect on HspA1A's ATPase activity. In contrast, PS-binding showed subtle but consistent increases in HspA1A's refolding activities. Furthermore, using a Lysine-71-Alanine mutation (K71A; a null-ATPase mutant) of HspA1A we show that although K71A binds to PS with affinities similar to the wild-type (WT), the mutated protein associates with lipids three times faster and dissociates 300 times faster than the WT HspA1A. These observations suggest a two-step binding model including an initial interaction of HspA1A with lipids followed by a conformational change of the HspA1A-lipid complex, which accelerates the binding reaction. Together these findings strongly support the notion that the chaperone and lipid-binding activities of HspA1A are dependent but the regions mediating these functions do not overlap and provide the basis for future interventions to inhibit HspA1A's PM-translocation in tumor cells, making them sensitive to radiation therapy.

Functional characterization of natural variants found on the major stress inducible 70-kDa heat shock gene, HSPA1A, in humans.

In this report, we investigated the effects of natural single nucleotide polymorphisms on the function of HSPA1A, the major stress-inducible Hsp70 gene in humans. We first established that all mutant proteins retain their ability to hydrolyze ATP, but three of them had a significantly lower rate of ATP hydrolysis as compared to the wild-type (WT) protein. We also used Isothermal Titration Calorimetry and found that although all mutants bind to protein substrate with dissociation constants similar to the WT protein, four of them had increased reaction entropies. We also tested whether these mutations affect the ability of HSPA1A to refold heat-denatured luciferase. These assays revealed that one mutation resulted in significantly lower levels while a second one resulted in higher levels of the refolded enzyme. We then determined whether the mutations affected the ability of HSPA1A to prevent apoptosis caused by poly-glutamine carrying huntingtin proteins. This assay determined that three of the mutations caused increased cell apoptosis as compared to the WT. Our results reveal that although none of these naturally occurring mutations exists on positions of known function, some alter the molecular chaperone activities of HSPA1A most probably by affecting the allosteric communication between its two major domains.

Parents' preparedness for their infants' discharge following first-stage cardiac surgery: development of a parental early warning tool.

UNLABELLED: Aim The aim of this study was to explore parental preparedness for discharge and their experiences of going home with their infant after the first-stage surgery for a functionally univentricular heart. BACKGROUND: Technological advances worldwide have improved outcomes for infants with a functionally univentricular heart over the last 3 decades; however, concern remains regarding mortality in the period between the first and second stages of surgery. The implementation of home monitoring programmes for this group of infants has improved this initial inter-stage survival; however, little is known about parents' experiences of going home, their preparedness for discharge, and parents' recognition of deterioration in their fragile infant. METHOD: This study was conducted in 2011-2013; eight sets of parents were consulted in the research planning stage in September, 2011, and 22 parents with children aged 0-2 years responded to an online survey during November, 2012-March, 2013. Description of categorical data and deductive thematic analysis of the open-ended questions were undertaken. RESULTS: Not all parents were taught signs of deterioration or given written information specific to their baby. The following three themes emerged from the qualitative data: mixed emotions about going home, knowledge and preparedness, and support systems. CONCLUSIONS: Parents are not adequately prepared for discharge and are not well equipped to recognise deterioration in their child. There is a role for greater parental education through development of an early warning tool to address the gap in parents' understanding of signs of deterioration, enabling appropriate contact and earlier management by clinicians.

Muscle uncoupling protein 3 overexpression mimics endurance training and reduces circulating biomarkers of incomplete ß-oxidation.

Exercise substantially improves metabolic health, making the elicited mechanisms important targets for novel therapeutic strategies. Uncoupling protein 3 (UCP3) is a mitochondrial inner membrane protein highly selectively expressed in skeletal muscle. Here we report that moderate UCP3 overexpression (roughly 3-fold) in muscles of UCP3 transgenic (UCP3 Tg) mice acts as an exercise mimetic in many ways. UCP3 overexpression increased spontaneous activity (∼40%) and energy expenditure (∼5-10%) and decreased oxidative stress (∼15-20%), similar to exercise training in wild-type (WT) mice. The increase in complete fatty acid oxidation (FAO; ∼30% for WT and ∼70% for UCP3 Tg) and energy expenditure (∼8% for WT and 15% for UCP3 Tg) in response to endurance training was higher in UCP3 Tg than in WT mice, showing an additive effect of UCP3 and endurance training on these two parameters. Moreover, increases in circulating short-chain acylcarnitines in response to acute exercise in untrained WT mice were absent with training or in UCP3 Tg mice. UCP3 overexpression had the same effect as training in decreasing long-chain acylcarnitines. Outcomes coincided with a reduction in muscle carnitine acetyltransferase activity that catalyzes the formation of acylcarnitines. Overall, results are consistent with the conclusions that circulating acylcarnitines could be used as a marker of incomplete muscle FAO and that UCP3 is a potential target for the treatment of prevalent metabolic diseases in which muscle FAO is affected.

Enhancing discharge preparation for parents after complex cardiac surgery: evaluation of an e-learning resource for nurses.

Parents need to be appropriately prepared by knowledgeable healthcare professionals before going home with their infant following cardiac surgery for complex congenital heart disease (CHD). A quality improvement project was undertaken between 2018 and 2021 to equip healthcare professionals including children's cardiac nurses with the knowledge required to use the Congenital Heart Assessment Tool (CHAT) to teach parents how to monitor their infant at home. The project involved developing, implementing and evaluating an e-learning resource that included simulated scenarios captured on video. An online survey showed that users perceived the e-learning resource as having a positive effect on their understanding of complex CHD and their practice of preparing parents for discharge and home monitoring.

Exploring the implementation of key nursing roles in children's cardiac services.

BACKGROUND: Children's cardiac nursing roles have changed over the past decade. Royal College of Nursing (RCN) guidance and NHS England standards have been published with the aim of standardising and enhancing nursing care for children and young people with congenital heart disease (CHD) and their families. AIM: To explore the breath of implementation of key nursing roles in children's cardiac services across the UK and Ireland and to determine whether the roles met the RCN guidance and the NHS England standards. METHOD: A cross-sectional survey design was used. The 150 members of the Congenital Cardiac Nurses Association (CCNA) were invited via email to participate and were sent a link to an online survey. FINDINGS: Of the 150 potential respondents, 31 completed the survey. Overall, respondents believed that the RCN guidance had been implemented effectively and that children's cardiac nursing roles matched the RCN's example job descriptions. Respondents' comments suggested that implementation of the NHS England standards had been challenging and that progress in setting up key roles such as lead nurse, cardiac nurse educator and children's cardiac nurse specialist had been slow. Respondents felt that political and financial factors adversely affected recruitment. CONCLUSION: Since publication of the NHS England standards there has been some progress in the implementation, in children's cardiac services, of key nursing roles such as lead nurse and innovative nursing roles such as advanced nurse practitioner and research nurse. The findings of this study have informed the latest edition of the RCN guidance, which now includes the role of senior research nurse.

Real-World Adherence to Toxicity Management Guidelines for Immune-Related Adverse Events.

Immune checkpoint inhibitors (ICIs) affect immunologic homeostasis, leading to immune-related adverse events (irAEs). Early irAE detection and management can prevent significant morbidity and mortality. A retrospective chart review was performed to characterize irAEs associated with nivolumab, ipilimumab, and nivolumab plus ipilimumab in adult medical oncology patients in Nova Scotia Health-Central Zone from 2013-2020, and to describe adherence to toxicity management guidelines. Diarrhea/colitis, hepatitis, pneumonitis, nephrotoxicity, and cardiotoxicity were studied. Of 129 charts reviewed, 67 patients (51.9%) experienced at least one irAE for a total of 98 irAEs and a 1.5% fatality rate. Of these irAEs, 33.7% led to an emergency room visit. Patients were admitted to hospital and steroids were used in 24.5% and 35.7% of cases, respectively. In 17.3% of irAEs, ICIs were permanently discontinued. In 20.4% of irAEs, ICIs were held, and patients were monitored; while in 18.4%, ICIs were held until the irAE was Grade 0-1 (and until steroids were tapered). Almost 47% of irAEs were managed according to guidelines (14.3% were not), and 38.8% had no documented management. Patients receiving immunotherapy frequently experience irAEs with half of irAEs having documented management adhering to guidelines. As immunotherapy indications expand, it is important to ensure irAEs are documented and managed appropriately.

Interstitial Cystitis: An Update on the Disease Process and Treatment.

Interstitial cystitis (IC) is a chronic pain disorder of the bladder that is often underdiagnosed and mistreated. The difficulties in diagnosis stem from numerous theories regarding pathophysiology and etiology, including the breakdown of the glycosaminoglycan (GAG) layer, altered permeability of the urothelium, uroinflammation, and neural up-regulation. Dysfunction of the bladder increases the struggle for proper treatment and continues to prove difficult for health care providers to correctly diagnose and manage IC. If diagnosed and/or managed inappropriately, IC may contribute to increased symptom burden and decreased quality of life with respect to activities of daily living. When evaluating a patient's clinical presentation in combination with predefined risk factors, a health care provider can better establish a true diagnosis of IC, which, in turn, leads to better management of IC-associated symptoms. This review will help health care providers better understand the disease process by discussing pathophysiology, pain pathways, and common symptoms of IC, with the goal of better aiding them in the proper diagnosis and treatment of patients with IC.

Elevated Transaminases with Topical Diclofenac: A Case Report.

Drug-induced liver injury (DILI) has been described with numerous nonsteroidal anti-inflammatory drugs (NSAIDs). Oral diclofenac has been associated with DILI more frequently than other NSAIDs and requires periodic monitoring of liver transaminases and judicious consideration of clinical signs and symptoms of hepatotoxicity. Here we describe a case in which elevated liver transaminases in a 79-year-old female returned to normal following discontinuation of topical diclofenac 1% gel. Using a widely accepted drug reaction causality instrument, a rating of "definite" was assigned given the temporal sequence of drug exposure and transaminase changes. Further study is warranted to better guide prescribing of topical NSAIDs.

Paediatric cardiac nursing education: a national collaboration.

Educational courses for staff working in paediatric specialties may not be financially viable because of the small numbers involved and the difficulties that potential students have in getting released from their units. The UK Paediatric Cardiac Nurses Association worked with other groups to explore the feasibility of a national multi-professional paediatric cardiac education pathway. Three options were identified, including the continuation of local in-house provision with its associated variation in standards. The relative benefits and resource implications of each option were explored and approaches made to educational institutions for support in developing the pathway. A university with an established reputation for e-learning undertook this development and a post graduate certificate in Paediatric Cardiothoracic Practice will soon be available.