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Metabolites May 2024Purines are the building blocks of DNA/RNA, energy substrates, and cofactors. Purine metabolites, including ATP, GTP, NADH, and coenzyme A, are essential molecules in...
Purines are the building blocks of DNA/RNA, energy substrates, and cofactors. Purine metabolites, including ATP, GTP, NADH, and coenzyme A, are essential molecules in diverse biological processes such as energy metabolism, signal transduction, and enzyme activity. When purine levels increase, excess purines are either recycled to synthesize purine metabolites or catabolized to the end product uric acid. Purine catabolism increases during states of low oxygen tension (hypoxia and ischemia), but this metabolic pathway is incompletely understood in the context of histotoxic hypoxia (i.e., inhibition of oxygen utilization despite normal oxygen tension). In rabbits exposed to cyanide-a classical histotoxic hypoxia agent-we demonstrated significant increases in several concordant metabolites in the purine catabolic pathway (including plasma levels of uric acid, xanthosine, xanthine, hypoxanthine, and inosine) via mass spectrometry-based metabolite profiling. Pharmacological inhibition of the purine catabolic pathway with oxypurinol mitigated the deleterious effects of cyanide on skeletal muscle cytochrome c oxidase redox state, measured by non-invasive diffuse optical spectroscopy. Finally, plasma uric acid levels correlated strongly with those of lactic acid, an established clinical biomarker of cyanide exposure, in addition to a tissue biomarker of cyanide exposure (skeletal muscle cytochrome c oxidase redox state). Cumulatively, these findings not only shed light on the in vivo role(s) of cyanide but also have implications in the field of medical countermeasure (MCM) development.
PubMed: 38786756
DOI: 10.3390/metabo14050279 -
Cardiology Journal 2024Xanthine oxidase inhibitors, including allopurinol and febuxostat, are the first-line treatment of hyperuricemia. This meta-analysis investigated the association between... (Meta-Analysis)
Meta-Analysis
Xanthine oxidase inhibitors, including allopurinol and febuxostat, are the first-line treatment of hyperuricemia. This meta-analysis investigated the association between urate-lowering therapy and all-cause mortality in different chronic diseases to match its users and non-users in a real-world setting. Overall, 11 studies were included, which reported adjusted hazard ratios for all-cause mortality over at least 12 months. Meta-analysis of all included studies showed no effect of the therapy on all-cause mortality. However, subgroup analyses showed its beneficial effect in patients with chronic kidney disease (14% risk reduction) and hyperuricemia (14% risk reduction), but not in patients with heart failure (28% risk increase). Urate-lowering therapy reduces all-cause mortality among patients with hyperuricemia and chronic kidney disease, but it seems to increase mortality in patients with heart failure and should be avoided in this subgroup.
Topics: Humans; Xanthine Oxidase; Hyperuricemia; Cause of Death; Enzyme Inhibitors; Risk Factors; Allopurinol; Gout Suppressants; Febuxostat; Heart Failure; Uric Acid; Renal Insufficiency, Chronic; Adult
PubMed: 38771265
DOI: 10.5603/cj.97807 -
Research Square May 2024Urate-lowering treatment (ULT) to target with xanthine oxidase inhibitors (XOIs) paradoxically causes early increase in gouty arthritis flares. Because delayed reduction...
Effective xanthine oxidase inhibitor urate lowering therapy in gout is linked to an emergent serum protein interactome of complement activation and inflammation modulators.
BACKGROUND
Urate-lowering treatment (ULT) to target with xanthine oxidase inhibitors (XOIs) paradoxically causes early increase in gouty arthritis flares. Because delayed reduction in flare burden is mechanistically unclear, we tested for ULT inflammation responsiveness markers.
METHODS
Unbiased proteomics analyzed blood samples (baseline, 48 weeks ULT) in two, independent ULT out trial cohorts (n = 19, n = 30). STRING-db and multivariate analyses supplemented determinations of altered proteins via Wilcoxon matched pairs signed rank testing in XOI ULT responders. Mechanistic studies characterized proteomes of cultured XOI-treated murine bone marrow macrophages (BMDMs).
RESULTS
At 48 weeks ULT, serum urate normalized in all gout patients, and flares declined, with significantly altered proteins (p < 0.05) in clustering and proteome networks in sera and peripheral blood mononuclear cells. Serum proteome changes included decreased complement C8 heterotrimer C8A and C8G chains and chemokine PPBP/CXCL7, and increased urate crystal phagocytosis inhibitor sCD44. In both cohorts, a treatment-emergent serum interactome included key gouty inflammation mediators (C5, IL-1B, CXCL8, IL6). Last, febuxostat inhibited complement activation pathway proteins in cultured BMDMs.
CONCLUSIONS
Reduced gout flares are kinked with a XOI-treatment emergent complement- and inflammation-regulatory serum protein interactome. Serum and leukocyte proteomes could help identify onset of anti-inflammatory responsiveness to ULT in gout.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT02579096, posted October 19, 2015.
PubMed: 38766125
DOI: 10.21203/rs.3.rs-4278877/v1 -
Annals of Medicine Dec 2024Uric acid (UA) levels in blood serum have been associated with hypertension, indicating a potential causal relationship between high serum UA levels and the progression... (Review)
Review
Uric acid (UA) levels in blood serum have been associated with hypertension, indicating a potential causal relationship between high serum UA levels and the progression of hypertension. Therefore, the reduction of serum UA level is considered a potential strategy for lowering and mitigating blood pressure. If an individual is at risk of developing or already manifesting elevated blood pressure, this intervention could be an integral part of a comprehensive treatment plan. By addressing hyperuricaemia, practitioners may subsidize the optimization of blood pressure regulation, which illustrates the importance of addressing UA levels as a valuable strategy within the broader context of hypertension management. In this analysis, we outlined the operational principles of effective xanthine oxidase inhibitors for the treatment of hyperuricaemia and hypertension, along with an exploration of the contribution of nanotechnology to this field.
Topics: Humans; Hyperuricemia; Hypertension; Uric Acid; Xanthine Oxidase; Blood Pressure; Nanotechnology; Antihypertensive Agents
PubMed: 38753584
DOI: 10.1080/07853890.2024.2352022 -
Health Expectations : An International... Jun 2024Gout management remains suboptimal despite safe and effective urate-lowering therapy. Self-monitoring of urate may improve gout management, however, the acceptability of...
INTRODUCTION
Gout management remains suboptimal despite safe and effective urate-lowering therapy. Self-monitoring of urate may improve gout management, however, the acceptability of urate self-monitoring by people with gout is unknown. The aim of this study was to explore the experiences of urate self-monitoring in people with gout.
METHODS
Semistructured interviews were conducted with people taking urate-lowering therapy (N = 30) in a 12-month trial of urate self-monitoring in rural and urban Australia. Interviews covered the experience of monitoring and its effect on gout self-management. Deidentified transcripts were analysed thematically.
RESULTS
Participants valued the ability to self-monitor and gain more understanding of urate control compared with the annual monitoring ordered by their doctors. Participants indicated that self-monitoring at home was easy, convenient and informed gout self-management behaviours such as dietary modifications, hydration, exercise and medication routines. Many participants self-monitored to understand urate concentration changes in response to feeling a gout flare was imminent or whether their behaviours, for example, alcohol intake, increased the risk of a gout flare. Urate concentrations were shared with doctors mainly when they were above target to seek management support, and this led to allopurinol dose increases in some cases.
CONCLUSION
Urate self-monitoring was viewed by people with gout as convenient and useful for independent management of gout. They believed self-monitoring achieved better gout control with a less restricted lifestyle. Urate data was shared with doctors at the patient's discretion and helped inform clinical decisions, such as allopurinol dose changes. Further research on implementing urate self-monitoring in routine care would enable an evaluation of its impact on medication adherence and clinical outcomes, as well as inform gout management guidelines.
PATIENT OR PUBLIC CONTRIBUTION
One person with gout, who was not a participant, was involved in the study design by providing feedback and pilot testing the semistructured interview guide. In response to their feedback, subsequent modifications to the interview guide were made to improve the understandability of the questions from a patient perspective. No additional questions were suggested.
Topics: Humans; Gout; Male; Female; Middle Aged; Uric Acid; Interviews as Topic; Aged; Australia; Gout Suppressants; Self-Management; Self Care; Adult; Qualitative Research
PubMed: 38742836
DOI: 10.1111/hex.14071 -
Brain Research Bulletin Jul 2024Epilepsy is a common neurological disease characterized by the recurrent, paroxysmal, and unprovoked seizures. It has been shown that hyperuricemia enhances and... (Review)
Review
Epilepsy is a common neurological disease characterized by the recurrent, paroxysmal, and unprovoked seizures. It has been shown that hyperuricemia enhances and associated with the development and progression of epilepsy through induction of inflammation and oxidative stress. In addition, uric acid is released within the brain and contributes in the development of neuronal hyperexcitability and epileptic seizure. Brain uric acid acts as damage associated molecular pattern (DAMP) activates the immune response and induce the development of neuroinflammation. Therefore, inhibition of xanthine oxidase by allopurinol may reduce hyperuricemia-induced epileptic seizure and associated oxidative stress and inflammation. However, the underlying mechanism of allopurinol in the epilepsy was not fully elucidated. Therefore, this review aims to revise from published articles the link between hyperuricemia and epilepsy, and how allopurinol inhibits the development of epileptic seizure.
Topics: Hyperuricemia; Allopurinol; Humans; Epilepsy; Animals; Oxidative Stress; Uric Acid; Xanthine Oxidase; Brain
PubMed: 38723694
DOI: 10.1016/j.brainresbull.2024.110973 -
Haematologica May 2024Not available.
Not available.
PubMed: 38721742
DOI: 10.3324/haematol.2024.285080 -
ELife May 2024Adenine phosphoribosyltransferase (APRT) and hypoxanthine-guanine phosphoribosyltransferase (HGPRT) are two structurally related enzymes involved in purine recycling in...
Adenine phosphoribosyltransferase (APRT) and hypoxanthine-guanine phosphoribosyltransferase (HGPRT) are two structurally related enzymes involved in purine recycling in humans. Inherited mutations that suppress HGPRT activity are associated with Lesch-Nyhan disease (LND), a rare X-linked metabolic and neurological disorder in children, characterized by hyperuricemia, dystonia, and compulsive self-injury. To date, no treatment is available for these neurological defects and no animal model recapitulates all symptoms of LND patients. Here, we studied LND-related mechanisms in the fruit fly. By combining enzymatic assays and phylogenetic analysis, we confirm that no HGPRT activity is expressed in , making the APRT homolog (Aprt) the only purine-recycling enzyme in this organism. Whereas APRT deficiency does not trigger neurological defects in humans, we observed that mutants show both metabolic and neurobehavioral disturbances, including increased uric acid levels, locomotor impairments, sleep alterations, seizure-like behavior, reduced lifespan, and reduction of adenosine signaling and content. Locomotor defects could be rescued by Aprt re-expression in neurons and reproduced by knocking down selectively in the protocerebral anterior medial (PAM) dopaminergic neurons, the mushroom bodies, or glia subsets. Ingestion of allopurinol rescued uric acid levels in -deficient mutants but not neurological defects, as is the case in LND patients, while feeding adenosine or -methyladenosine (mA) during development fully rescued the epileptic behavior. Intriguingly, pan-neuronal expression of an LND-associated mutant form of human HGPRT (I42T), but not the wild-type enzyme, resulted in early locomotor defects and seizure in flies, similar to deficiency. Overall, our results suggest that could be used in different ways to better understand LND and seek a cure for this dramatic disease.
Topics: Animals; Drosophila melanogaster; Lesch-Nyhan Syndrome; Purines; Disease Models, Animal; Behavior, Animal; Hypoxanthine Phosphoribosyltransferase; Drosophila Proteins; Locomotion
PubMed: 38700995
DOI: 10.7554/eLife.88510 -
RMD Open Apr 2024Currently, gout management, particularly urate-lowering therapy (ULT), is often suboptimal. Nurses successfully manage various diseases including gout. As gout...
OBJECTIVES
Currently, gout management, particularly urate-lowering therapy (ULT), is often suboptimal. Nurses successfully manage various diseases including gout. As gout prevalence is rising, and rheumatologists and general practitioners face shortages, a new approach is imperative. This real-life prospective cohort study evaluated the effectiveness of nurse-led care employing a treat-to-target strategy for gout management over a 2-year period.
METHODS
All consecutively confirmed gout patients were included. The nurse-led clinic provided a structured treatment plan with consultations, patient leaflets, telephone contacts and laboratory monitoring. After a year of nurse-led care, patients transitioned to continued care in general practice. Follow-up data were complete through registries. The primary outcome was achieving target p-urate levels (<0.36 mmol/L) at 2 years after diagnosis. Secondary outcomes included treatment continuation and achievement of target p-urate levels in specific subgroups. The results were compared with patients diagnosed in the same clinic but followed up in 'usual care'.
RESULTS
In the nurse-led group (n=114), 83% achieved target p-urate levels and ULT was continued by 98%. This trend persisted across various patient subgroups. Only 44% of patients in usual care achieved target p-urate and with insufficient doses of allopurinol . Nurse-led care involved an average of two visits and three telephone contacts over 336 days. The 2-year mortality rate was 15%.
CONCLUSIONS
Nurse-led gout care, employing a targeted approach, was associated with a very high uptake of and adherence to ULT. The encouraging results were not achieved in usual care although a direct comparison might be influenced by selection bias.
Topics: Humans; Gout; Male; Female; Middle Aged; Aged; Uric Acid; Prospective Studies; Gout Suppressants; Treatment Outcome; Practice Patterns, Nurses'; Allopurinol; Disease Management
PubMed: 38663881
DOI: 10.1136/rmdopen-2024-004179