166 research outputs found

    Regulation of Nuclear PLCĪ²1 by a Novel Binding Partner called TRAX

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    Comorbidity, Pain, Utilization, and Psychosocial Outcomes in Older versus Younger Sickle Cell Adults: The PiSCES Project

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    Background. Patients with SCD now usually live well into adulthood. Whereas transitions into adulthood are now often studied, little is published about aging beyond the transition period. We therefore studied age-associated SCD differences in utilization, pain, and psychosocial variables. Methods. Subjects were 232 adults in the Pain in Sickle Cell Epidemiology Study (PiSCES). Data included demographics, comorbidity, and psychosocial measures. SCD-related pain and health care utilization were recorded in diaries. We compared 3 age groups: 16ā€“25 (transition), 26ā€“36 (younger adults), and 37ā€“64 (older adults) years. Results. Compared to the 2 adult groups, the transition group reported fewer physical challenges via comorbidities, somatic complaints, and pain frequency, though pain intensity did not differ on crisis or noncrisis pain days. The transition group utilized opioids less often, made fewer ambulatory visits, and had better quality of life, but these differences disappeared after adjusting for pain and comorbidities. However, the transition group reported more use of behavioral coping strategies. Conclusion. We found fewer biological challenges, visits, and better quality of life, in transition-aged versus older adults with SCD, but more behavioral coping. Further study is required to determine whether age-appropriate health care, behavioral, or other interventions could improve age-specific life challenges of patients with SCD

    PAR1 Agonists Stimulate APC-Like Endothelial Cytoprotection and Confer Resistance to Thromboinflammatory Injury

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    Stimulation of protease-activated receptor 1 (PAR1) on endothelium by activated protein C (APC) is protective in several animal models of disease, and APC has been used clinically in severe sepsis and wound healing. Clinical use of APC, however, is limited by its immunogenicity and its anticoagulant activity. We show that a class of small molecules termed ā€œparmodulinsā€ that act at the cytosolic face of PAR1 stimulates APC-like cytoprotective signaling in endothelium. Parmodulins block thrombin generation in response to inflammatory mediators and inhibit platelet accumulation on endothelium cultured under flow. Evaluation of the antithrombotic mechanism showed that parmodulins induce cytoprotective signaling through GĪ²Ī³, activating a PI3K/Akt pathway and eliciting a genetic program that includes suppression of NF-ĪŗBā€“mediated transcriptional activation and up-regulation of select cytoprotective transcripts. STC1 is among the up-regulated transcripts, and knockdown of stanniocalin-1 blocks the protective effects of both parmodulins and APC. Induction of this signaling pathway in vivo protects against thromboinflammatory injury in blood vessels. Small-molecule activation of endothelial cytoprotection through PAR1 represents an approach for treatment of thromboinflammatory disease and provides proof-of-principle for the strategy of targeting the cytoplasmic surface of GPCRs to achieve pathway selective signaling

    Parmodulins Inhibit Thrombus Formation Without Inducing Endothelial Injury Caused by Vorapaxar

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    Protease-activated receptor-1 (PAR1) couples the coagulation cascade to platelet activation during myocardial infarction and to endothelial inflammation during sepsis. This receptor demonstrates marked signaling bias. Its activation by thrombin stimulates prothrombotic and proinflammatory signaling, whereas its activation by activated protein C (APC) stimulates cytoprotective and antiinflammatory signaling. A challenge in developing PAR1-targeted therapies is to inhibit detrimental signaling while sparing beneficial pathways. We now characterize a novel class of structurally unrelated small-molecule PAR1 antagonists, termed parmodulins, and compare the activity of these compounds to previously characterized compounds that act at the PAR1 ligandā€“binding site. We find that parmodulins target the cytoplasmic face of PAR1 without modifying the ligand-binding site, blocking signaling through GĪ±q but not GĪ±13 in vitro and thrombus formation in vivo. In endothelium, parmodulins inhibit prothrombotic and proinflammatory signaling without blocking APC-mediated pathways or inducing endothelial injury. In contrast, orthosteric PAR1 antagonists such as vorapaxar inhibit all signaling downstream of PAR1. Furthermore, exposure of endothelial cells to nanomolar concentrations of vorapaxar induces endothelial cell barrier dysfunction and apoptosis. These studies demonstrate how functionally selective antagonism can be achieved by targeting the cytoplasmic face of a G-proteinā€“coupled receptor to selectively block pathologic signaling while preserving cytoprotective pathways

    Health related quality of life in sickle cell patients: The PiSCES project

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    BACKGROUND: Sickle cell disease (SCD) is a chronic disease associated with high degrees of morbidity and increased mortality. Health-related quality of life (HRQOL) among adults with sickle cell disease has not been widely reported. METHODS: We administered the Medical Outcomes Study 36-item Short-Form to 308 patients in the Pain in Sickle Cell Epidemiology Study (PiSCES) to assess HRQOL. Scales included physical function, physical and emotional role function, bodily pain, vitality, social function, mental health, and general health. We compared scores with national norms using t-tests, and with three chronic disease cohorts: asthma, cystic fibrosis and hemodialysis patients using analysis of variance and Dunnett's test for comparison with a control. We also assessed whether SCD specific variables (genotype, pain, crisis and utilization) were independently predictive of SF-36 subscales, controlling for socio-demographic variables using regression. RESULTS: Patients with SCD scored significantly worse than national norms on all subscales except mental health. Patients with SCD had lower HRQOL than cystic fibrosis patients except for mental health. Scores were similar for physical function, role function and mental health as compared to asthma patients, but worse for bodily pain, vitality, social function and general health subscales. Compared to dialysis patients, sickle cell disease patients scored similarly on physical role and emotional role function, social functioning and mental health, worse on bodily pain, general health and vitality and better on physical functioning. Surprisingly, genotype did not influence HRQOL except for vitality. However, scores significantly decreased as pain levels increased. CONCLUSION: SCD patients experience health related quality of life worse than the general population, and in general, their scores were most similar to patients undergoing hemodialysis. Practitioners should regard their HRQOL as severely compromised. Interventions in SCD should consider improvements in health related quality of life as important outcomes

    Pain site frequency and location in sickle cell disease: The PiSCES project

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    Treatment options for sickle cell disease (SCD) pain could be tailored to pain locations. But few epidemiologic descriptions of SCD pain location exist; these are based on few subjects over short time periods. We examined whether SCD pain locations vary by disease genotype, gender, age, frequency of pain, depression, pain crisis or healthcare utilization

    Development and validation of the satisfaction with treatment for pain questionnaire (STPQ) among patients with sickle cell disease

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    A brief measure of patient satisfaction with treatment for pain is needed to help improve the treatment of painful episodes caused by sickle cell disease (SCD), especially during and after the transition from paediatric to adult care. Focus groups of 28 adolescent and adult patients were consulted about the content, clarity and relevance of 30 potential items, resulting in an 18-item version. This was validated by analysing questionnaire responses from 120 patients aged 12-53 years. Confirmatory factor analysis and item analysis indicated five subscales with high internal reliability: ā€˜Communication and Involvementā€™ (6 items, Ī±=0.87); ā€˜Respect and Dignityā€™ (3 items, Ī±=0.82); ā€˜Pain Controlā€™ (3 items, Ī±=0.91); ā€˜Staff Attitudes and Behaviourā€™ (4 items, Ī±=0.88); and ā€˜Overall Satisfactionā€™ (2 items, Ī±=0.85); plus a Total Satisfaction score (18 items, Ī±=0.96). High negative correlations with the Picker Patient Experience Questionnaire, a measure of problem experiences, indicated good convergent validity. Lower satisfaction scores among patients aged over 18 years, those admitted via the emergency department, those treated by non-specialist hospital staff, and those reporting more breakthrough pain indicated good concurrent validity. The questionnaire provides a convenient brief measure that can be used to inform and evaluate improvements in healthcare for adolescent and adult patients with SCD, and could potentially be adapted for other painful conditions.Bartā€™s Charity Strategic Research Grant (Reference Number 1704); non-restricted financial grants from Kyowa Kirin and Mundipharma; University of Derby Undergraduate Research Scholarship awards; University of Derby REF reinvestment programme

    Identification of a Novel Binding Partner of Phospholipase CĪ²1: Translin-Associated Factor X

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    Mammalian phospholipase CĪ²1 (PLCĪ²1) is activated by the ubiquitous GĪ±q family of G proteins on the surface of the inner leaflet of plasma membrane where it catalyzes the hydrolysis of phosphatidylinositol 4,5 bisphosphate. In general, PLCĪ²1 is mainly localized on the cytosolic plasma membrane surface, although a substantial fraction is also found in the cytosol and, under some conditions, in the nucleus. The factors that localize PLCĪ²1in these other compartments are unknown. Here, we identified a novel binding partner, translin-associated factor X (TRAX). TRAX is a cytosolic protein that can transit into the nucleus. In purified form, PLCĪ²1 binds strongly to TRAX with an affinity that is only ten-fold weaker than its affinity for its functional partner, GĪ±q. In solution, TRAX has little effect on the membrane association or the catalytic activity of PLCĪ²1. However, TRAX directly competes with GĪ±q for PLCĪ²1 binding, and excess TRAX reverses GĪ±q activation of PLCĪ²1. In C6 glia cells, endogenous PLCĪ²1 and TRAX colocalize in the cytosol and the nucleus, but not on the plasma membrane where TRAX is absent. In Neuro2A cells expressing enhanced yellow and cyano fluorescent proteins (i.e., eYFP- PLCĪ²1 and eCFP-TRAX), Fƶrster resonance energy transfer (FRET) is observed mostly in the cytosol and a small amount is seen in the nucleus. FRET does not occur at the plasma membrane where TRAX is not found. Our studies show that TRAX, localized in the cytosol and nucleus, competes with plasma-membrane bound GĪ±q for PLCĪ²1 binding thus stabilizing PLCĪ²1 in other cellular compartments

    Identification of Nucleic Acid Binding Sites on Translin-Associated Factor X (TRAX) Protein

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    Translin and TRAX proteins play roles in very important cellular processes such as DNA recombination, spatial and temporal expression of mRNA, and in siRNA processing. Translin forms a homomeric nucleic acid binding complex and binds to ssDNA and RNA. However, a mutant translin construct that forms homomeric complex lacking nucleic acid binding activity is able to form fully active heteromeric translin-TRAX complex when co-expressed with TRAX. A substantial progress has been made in identifying translin sites that mediate its binding activity, while TRAX was thought not to bind DNA or RNA on its own. We here for the first time demonstrate nucleic acid binding to TRAX by crosslinking radiolabeled ssDNA to heteromeric translin-TRAX complex using UV-laser. The TRAX and translin, photochemically crosslinked with ssDNA, were individually detected on SDS-PAGE. We mutated two motifs in TRAX and translin, designated B2 and B3, to help define the nucleic acid binding sites in the TRAX sequence. The most pronounced effect was observed in the mutants of B3 motif that impaired nucleic acid binding activity of the heteromeric complexes. We suggest that both translin and TRAX are binding competent and contribute to the nucleic acid binding activity

    Does anxiety predict the use of urgent care by people with long term conditions? A systematic review with meta-analysis.

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    Objective: The role of anxiety in the use of urgent care in people with long term conditions is not fully understood. A systematic review was conducted with meta-analysis to examine the relationship between anxiety and future use of urgent healthcare among individuals with one of four long term conditions: diabetes; coronary heart disease, chronic obstructive pulmonary disease and asthma. Methods: Electronic searches of MEDLINE, EMBASE, PSYCINFO, CINAHL, the British Nursing Library and the Cochrane Library were conducted These searches were supplemented by hand-searching bibliographies, citation tracing eligible studies and asking experts within the field about relevant studies. Studies were eligible for inclusion if they: a) used a standardised measure of anxiety, b) used prospective cohort design, c) included adult patients diagnosed with coronary heart disease (CHD), asthma, diabetes or chronic obstructive pulmonary disease (COPD), d) assessed urgent healthcare use prospectively. Data regarding participants, methodology, and association between anxiety and urgent care use was extracted from studies eligible for inclusion. Odds ratios were calculated for each study and pooled using random effects models. Results: 8 independent studies were identified for inclusion in the meta-analysis, with a total of 28,823 individual patients. Pooled effects indicate that anxiety is not associated with an increase in the use of urgent care (OR. =. 1.078, p. =. 0.476), regardless of the type of service, or type of medical condition. Conclusions: Anxiety is not associated with increased use of urgent care. This finding is in contrast to similar studies which have investigated the role of depression as a risk factor for use of urgent care
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