Impact of Hyper- and Hypo-Uricemia on Kidney Function

Colorimetric array sensor based on bimetallic nitrogen-doped carbon-based nanozyme material to detect multiple antioxidants

Copper-cobalt bimetallic nitrogen-doped carbon-based nanoenzymatic materials (CuCo@NC) were synthesized using a one-step pyrolysis process. A three-channel colorimetric sensor array was constructed for the detection of seven antioxidants, including cysteine (Cys), uric acid (UA), tea polyphenols (TP), lysine (Lys), ascorbic acid (AA), glutathione (GSH), and dopamine (DA). CuCo@NC with peroxidase activity was used to catalyze the oxidation of TMB by H2O2 at three different ratios of metal sites. The ability of various antioxidants to reduce the oxidation products of TMB (ox TMB) varied, leading to distinct absorbance changes. Linear discriminant analysis (LDA) results showed that the sensor array was capable of detecting seven antioxidants in buffer and serum samples. It could successfully discriminate antioxidants with a minimum concentration of 10 nM. Thus, multifunctional sensor arrays based on CuCo@NC bimetallic nanoenzymes not only offer a promising strategy for identifying various antioxidants but also expand their applications in medical diagnostics and environmental analysis of food.

Recent Advances in Dysuricemia: Toward Optimal Serum Urate Level

We are pleased to present the Special Issue "Dysuricemia: Recent Advances in Urate Research from Hypouricemia to Hyperuricemia/Gout" [...].

Design, synthesis, and biological evaluation of 3-phenyl substituted pyridine derivatives as potential dual inhibitors of XOR and URAT1

Xanthine oxidoreductase (XOR) and uric acid transporter 1 (URAT1) are two most widely studied targets involved in production and reabsorption of uric acid, respectively. Marketed drugs almost target XOR or URAT1, but sometimes, single agents might not achieve aim of lowering uric acid to ideal value in clinic. Thus, therapeutic strategies of combining XOR inhibitors with uricosuric drugs were proposed and implemented. Based on our initial work of virtual screening, A and B were potential hits for dual-targeted inhibitors on XOR/URAT1. By docking A/B with XOR/URAT1 respectively, compounds I1-7 were designed to get different degree of inhibition effect on XOR and URAT1, and I7 showed the best inhibitory effect on XOR (IC50 = 0.037 ± 0.001 μM) and URAT1 (IC50 = 546.70 ± 32.60 μM). Further docking research on I7 with XOR/URAT1 led to the design of compounds II with the significantly improved inhibitory activity on XOR and URAT1, such as II11 and II15. Especially, for II15, the IC50 of XOR is 0.006 ± 0.000 μM, superior to that of febuxostat (IC50 = 0.008 ± 0.000 μM), IC50 of URAT1 is 12.90 ± 2.30 μM, superior to that of benzbromarone (IC50 = 27.04 ± 2.55 μM). In acute hyperuricemia mouse model, II15 showed significant uric acid lowering effect. The results suggest that II15 had good inhibitory effect on XOR/URAT1, with the possibility for further investigation in in-vivo models of hyperuricemia.

Hyperuricemia and gout enhanced the risk of long-term mortality in hypertension: insights from the National Health and Nutrition Examination Survey 2007-2018

BACKGROUND

Asymptomatic hyperuricemia (HUA) and normouricemic gout are common in clinic but recommendations for them in hypertension management are absent. The present study aims to simultaneously evaluate the effect of HUA and gout on long-term mortality in hypertension.

METHODS

Individuals from 2007-2018 National Health and Nutrition Examination Survey were enrolled. Hazard ratios and 95% confidence intervals (CIs) were calculated with the aid of the Cox proportional-hazards model. The restricted cubic spline (RCS) analysis was made to show the dose-response relationship between uric acid and mortality. All-cause mortality and cardiovascular mortality were compared using the Kaplan-Meier curve with a log-rank test.

RESULTS

Thirty thousand eight hundred and nineteen eligible individuals were included, of which 5841 suffered from HUA and 1476 suffered from gout. During a median follow-up of 7.25 (95% CI 7.18-7.32) years, 2924 (6.8%) patients died, including 722 (1.6%) cases of cardiovascular death. Hypertensive patients with HUA and gout showed 1.34 and 1.29 times higher all-cause mortality compared with those without HUA or gout. For hypertensive patients without gout, HUA was significantly associated with higher risk of all-cause [1.27 (1.13, 1.43)] and cardiovascular [1.80 (1.44, 2.24)] mortality compared with normouricemia. However, for hypertensive patients without HUA, gout was associated with a higher mortality but not statistically significant. A J-shaped relationship was found between serum uric acid and mortality.

CONCLUSION

HUA and gout are additive risk factors for all-cause and cardiovascular mortality in hypertension. Furthermore, asymptomatic HUA is significantly associated with poor long-term prognosis but normouricemic gout is not.

Changes in Urinary Uric Acid Concentration after Dotinurad Administration to Patients with Hyperuricemia: A Post Hoc Analysis of Two Clinical Trials in Japan

Dotinurad has been approved in Japan as a selective urate reabsorption inhibitor for the treatment of gout and hyperuricemia. The relationship between uric acid crystallization and the use of uricosuric drugs is widely acknowledged; however, the relationship between changes in urinary uric acid concentration and urine pH or volume has not been sufficiently analyzed. Therefore, we investigated the changes in urinary uric acid concentration following dotinurad administration as well as the relationship between urine pH or volume and urinary uric acid concentration. This post hoc analysis used data from 2 clinical trials that included 12 and 26 patients with hyperuricemia who received dotinurad treatment (for 7 days on an inpatient basis and 14 weeks on an outpatient basis, respectively). The urinary uric acid concentration transiently increased in the early stages of dotinurad use and when its dose was increased, but decreased over time. No uric acid concentrations exceeded the soluble limit at any urine pH. An inverse correlation was observed between urine volume and urinary uric acid concentration. This study highlights the significance of adequately managing urinary uric acid concentrations by increasing urine volume and alkalinizing urine to prevent uric acid crystallization during dotinurad administration.

Asterias forbesi-Inspired SERS Substrates for Wide-Range Detection of Uric Acid

Uric acid (UA), the final metabolite of purine, is primarily excreted through urine to maintain an appropriate concentration in the bloodstream. However, any malfunction in this process can lead to complications due to either deficiency or excess amount of UA. Hence, the development of a sensor platform with a wide-range detection is crucial. To realize this, we fabricated a surface-enhanced Raman spectroscopy (SERS) substrate inspired by a type of starfish with numerous protrusions, Asterias forbesi. The Asterias forbesi-inspired SERS (AF-SERS) substrate utilized an Au@Ag nanostructure and gold nanoparticles to mimic the leg and protrusion morphology of the starfish. This substrate exhibited excellent Raman performance due to numerous hotspots, demonstrating outstanding stability, reproducibility, and repeatability. In laboratory settings, we successfully detected UA down to a concentration of 1.16 nM (limit of detection) and demonstrated selectivity against various metabolites. In the experiments designed for real-world application, the AF-SERS substrate detected a broad range of UA concentrations, covering deficiencies and excesses, in both serum and urine samples. These results underscore the potential of the developed AF-SERS substrate as a practical detection platform for UA in real-world applications.