The Role of Oxidative Stress in Hyperuricemia and Xanthine Oxidoreductase (XOR) Inhibitors

Mechanism of Reactive Oxygen Species-Guided Immune Responses in Gouty Arthritis and Potential Therapeutic Targets

Gouty arthritis (GA) is an inflammatory disease caused by monosodium urate (MSU) crystals deposited in the joint tissues causing severe pain. The disease can recur frequently and tends to form tophus in the joints. Current therapeutic drugs for the acute phase of GA have many side effects and limitations, are unable to prevent recurrent GA attacks and tophus formation, and overall efficacy is unsatisfactory. Therefore, we need to advance research on the microscopic mechanism of GA and seek safer and more effective drugs through relevant targets to block the GA disease process. Current research shows that the pathogenesis of GA is closely related to NLRP3 inflammation, oxidative stress, MAPK, NET, autophagy, and Ferroptosis. However, after synthesizing and sorting out the above mechanisms, it is found that the presence of ROS is throughout almost the entire spectrum of micro-mechanisms of the gout disease process, which combines multiple immune responses to form a large network diagram of complex and tight connections involved in the GA disease process. Current studies have shown that inflammation, oxidative stress, cell necrosis, and pathological signs of GA in GA joint tissues can be effectively suppressed by modulating ROS network-related targets. In this article, on the one hand, we investigated the generative mechanism of ROS network generation and its association with GA. On the other hand, we explored the potential of related targets for the treatment of gout and the prevention of tophus formation, which can provide effective reference ideas for the development of highly effective drugs for the treatment of GA.

The predictive value of TyG and lipid ratios on the development of complications and hyperuricemia in patients with type 2 diabetes mellitus

Investigate the predictive value of TyG and lipid ratios on the development of complications and HUA in patients with T2DM. A retrospective cross-sectional study involving 9488 T2DM patients was conducted. They were divided into HUA and NUA group base on SUA level and divided into with and without complications groups according to the diagnosis of the endocrinologist. Necessary information and biochemical parameters were recorded during outpatient visit. TyG index and lipid ratios were calculated, and statistical analysis was carried out to correlate the calculated values and HUA using SPSS version 26.0 for Windows. TyG and lipid ratios were significantly higher in T2DM with HUA or with complications than those with NUA or without complications (p < 0.05). Regression analysis adjusting for confounding factors found TyG (adjusted OR = 1.54; 95% CI: 1.31-1.82; p < 0.05), TG/HDL-C (adjusted OR = 1.21; 95% CI: 1.04-1.40; p < 0.05) and TC/HDL (adjusted OR = 1.36; 95% CI: 1.17-1.57; p < 0.05) was risk factor of HUA in T2DM patients. TyG (adjusted OR = 1.21; 95% CI: 1.02-1.44; p < 0.05), TG/HDL (adjusted OR = 1.19; 95% CI: 1.03-1.38; p < 0.05) and Apo A/Apo B (adjusted OR = 1.41; 95% CI: 1.26-1.58; p < 0.05) was risk factor of complications in T2DM patients. TyG, TG/HDL-C, and TC/HDL can be used as early sensitive target in the occurrence of HUA in T2DM patients and TyG was the most influential risk factor. TyG, TG/HDL-C, and Apo A/Apo B can be used as early sensitive target in the occurrence of complications in T2DM patients and Apo A/Apo B was the most influential risk factor.

Omega-3 fatty acids abrogates oxido-inflammatory and mitochondrial dysfunction-associated apoptotic responses in testis of tamoxifen-treated rats

Background

Tamoxifen (TAM) is a widely used drug in patients with gynecomastia and breast cancer. TAM exerts its anticancer effects via its antiestrogenic activities. Unfortunately, TAM has been reported to exert gonadotoxic effects on male testes. Therefore, this study was designed to explore the possible associated mechanisms involved in TAM-induced testicular dysfunction and the possible ameliorative effects of omega-3 fatty acids (O3FA).

Methodology

Animals were randomly divided into control, O3FA, TAM, and TAM + O3FA. All treatment lasted for 28 days.

Results

TAM exposure impaired sperm qualities (count, motility, and normal morphology) and decreased testicular 3β-HSD and 17β-HSD. It was accompanied by a decline in serum testosterone and an increase in estradiol, luteinizing and follicle-stimulating hormones. These observed alterations were associated with an increase in testicular injury markers, oxido-inflammatory response, and mitochondria-mediated apoptosis. These observed alterations were ameliorated by O3FA treatments.

Conclusions

O3FA ameliorated TAM-induced testicular dysfunction in male Wistar rats by modulating XO/UA and Nrf2/NF-kb signaling and cytochrome c-mediated apoptosis in TAM-treated rats.

Urine metabolomics unravel the effects of short-term dietary interventions on oxidative stress and inflammation: a randomized controlled crossover trial

Dietary biomarkers in urine remain elusive when evaluating diet-induced oxidative stress and inflammation. In our previous study, we conducted a randomized controlled crossover trial to compare the short-term (4-weeks) effects of the balanced Korean diet (BKD) with Western diets, including the 2010 dietary guidelines for Americans (2010 DGA) and typical American diet (TAD), on various metabolic indices in obese Korean adults. Building on this work, the current research focuses on the impact of these dietary interventions on oxidative stress (d-ROMs and BAP) and inflammation (CRP, TNF-α, IL-6, IL-1β, MCP-1) biomarkers in serum, and the concurrent urine metabolomes. Each dietary regimen was in silico and experimentally examined for their antioxidant levels using ABTS, DPPH, and FRAP assays, as well as total flavonoid (TFC) and total phenolic (TPC) contents. We assessed post-intervention variations in oxidative stress and inflammation biomarkers in serum, as well as the urine metabolite profiles for the participants (n = 48, average age: 41 years). Antioxidant contents and associated total antioxidant capacity (TAC) were significantly higher for the recommended diets (BKD and 2010 DGA) compared to TAD (p < 0.05). Butanol extracts from recommended diets (BKD and 2010 DGA) showed significantly higher antioxidant activity compared to TAD in ABTS (p < 0.01), DPPH, and FRAP (p < 0.05) assays. Consistent results were observed in total phenolic and flavonoid contents, mirroring their respective antioxidant activities. Following the intervention period, oxidative stress & inflammation markers in serum varied marginally, however, the urine metabolite profiles were clearly demarcated for the BKD and Western dietary groups (PC1 = 5.41%). For BKD group, the pre- and post-intervention urine metabolite profiles were clearly segregated (PLS2 = 2.93%). Compared to TAD, urine extracts from the recommended dietary group showed higher abundance of benzoic acid & phenolic derivatives (VIP > 0.7, p < 0.05). Metabolites associated with oxidative stress were observed higher in the urine samples from Western dietary groups compared to BKD. Urine metabolomics data delineated the post-intervention effects of three dietary interventions which corroborates the respective findings for their effects on metabolic indices.

Transcriptomic Analysis Reveals the Effect of Urea on Metabolism of Nannochloropsis oceanica

The eukaryotic microalga Nannochloropsis oceanica represents a promising bioresource for the production of biofuels and pharmaceuticals. Urea, a crucial nutrient for the photosynthetic N. oceanica, stimulates the accumulation of substances such as lipids, which influence growth and physiology. However, the specific mechanisms by which N. oceanica responds and adapts to urea addition remain unknown. High-throughput mRNA sequencing and differential gene expression analysis under control and urea-added conditions revealed significant metabolic changes. This involved the differential expression of 2104 genes, with 1354 being upregulated and 750 downregulated, resulting in the reprogramming of crucial pathways such as carbon and nitrogen metabolism, photosynthesis, and lipid metabolism. The results specifically showed that genes associated with photosynthesis in N. oceanica were significantly downregulated, particularly those related to light-harvesting proteins. Interestingly, urea absorption and transport may depend not only on specialized transport channels such as urease but also on alternative transport channels such as the ABC transporter family and the CLC protein family. In addition, urea caused specific changes in carbon and lipid metabolism. Genes associated with the Calvin cycle and carbon concentration mechanisms were significantly upregulated. In lipid metabolism, the expression of genes associated with lipases and polyunsaturated fatty acid synthesis was highly activated. Furthermore, the expression of several genes involved in the tricarboxylic acid cycle and folate metabolism was enhanced, making important contributions to energy supply and the synthesis and modification of genes and macromolecules. Our observations indicate that N. oceanica actively and dynamically regulates the redistribution of carbon and nitrogen after urea addition, providing references for further research on the effects of urea on N. oceanica.

Association between oxidative balance score and serum uric acid and hyperuricemia: a population-based study from the NHANES (2011-2018)

Background

Oxidative Balance Score (OBS) is a novel indicator of the overall antioxidant/oxidant balance, providing a comprehensive reflection of the body's overall oxidative stress status, with higher OBS suggesting more substantial antioxidant exposures. We aimed to investigate the possible relationship between OBS with serum uric acid (SUA) and hyperuricemia.

Methods

Data utilized in this study were sourced from the 2011-2018 National Health and Nutrition Examination Survey (NHANES). Participants under 18 years old, those with ≤16 complete data out of 20 OBS components, incomplete serum uric acid data, and missing covariates were excluded from the analysis. OBS was computed by evaluating 16 nutrients and 4 lifestyle factors, encompassing 5 pro-oxidants and 15 antioxidants, guided by a priori knowledge of their relationship with oxidative stress.

Results

A total of 1,5096 individuals were included in our analysis with 49.7% being male, and an average age of 49.05 ± 17.56 years. The mean OBS was 19.76 ± 7.17. Hyperuricemia was present in 19.28% of participants. Due to the right-skewed distribution of the OBS, a natural log transformation was applied to address this issue, and Quartiles of lnOBS 1, 2, 3, and 4 were 1.10-2.56 (N=3526), 2.64-2.94 (N=3748), 3.00-3.22 (N=4026), and 3.26-3.61 (N=3796), respectively. Multivariable logistic regression showed that higher lnOBS quantiles were correlated with lower serum uric acid levels. Compared with the lowest lnOBS quantile, participants in the highest lnOBS quantile had a significant serum uric acid decrease of 16.94 μmol/L for each unit increase in lnOBS (β=-16.94, 95% CI: -20.44, -13.45). Similar negative associations were observed in the second-highest (β=-8.07, 95% CI: -11.45, -4.69) and third-highest (β=-11.69, 95% CI: -15.05, -8.34) lnOBS quantiles. The adjusted odds ratios (ORs) for hyperuricemia in Quartiles 1, 2, 3, and 4 were 1.00, 0.84 (95% CI: 0.75, 0.95), 0.78 (95% CI: 0.69, 0.88), and 0.62 (95% CI: 0.55, 0.71), respectively. Compared to Quartile 1, participants in Quartile 4 had a 38% lower prevalence of hyperuricemia. Subgroup analysis and interaction test showed that there was a significant dependence of sex between OBS and serum uric acid (p for interaction <0.05), but not hyperuricemia (p for interaction >0.05). Subgroup analysis stratified by age, BMI, hypertension, diabetes, and hyperlipidemia showed there is no significant dependence on these negative correlations (all p for interaction >0.05).

Conclusions

The serum uric acid levels and prevalence of hyperuricemia in US adults exhibited a negative association with OBS. By exploring this connection, our research aims to gain a better understanding of how oxidative balance affects the prevalence of hyperuricemia. This could provide valuable insights for developing preventive strategies and interventions for hyperuricemia. Additional large-scale prospective studies are required to explore the role of OBS in hyperuricemia further.

Synergistic Effects of Vitamin D and Exercise on Diabetes-induced Gonadotoxicity in Male Wistar Rats: Role of Xanthine Oxidase/Uric Acid and Nrf2/NfkB Signaling

Type 2 Diabetes mellitus (T2DM) is one of the oldest known chronic diseases, characterized by elevated fasting blood sugar (FBS). T2DM is a metabolic disorder that can distort the activities of multiple physiological systems, including the reproductive system. Although different drugs have been designed for managing this disorder, these drugs have been reported to have negative side effects. Hence, this study was designed to explore the possible synergistic effect of vitamin D and exercise on T2DM-induced testicular dysfunction. Thirty-six male Wistar rats were randomized into six (6) groups: control, diabetes untreated, diabetes treated with 1000 IU/kg of vitamin D, diabetes treated with 5 min/day of physical exercise, diabetes treated with vitamin D and exercise, diabetes treated with 180 mg/kg of metformin. T2DM induction led to a significant increase in FBS, lactate, and lactate dehydrogenase, and was reversed by vitamin D supplementation and exercise. Also, vitamin D and exercise synergistically blunted T2DM-induced oxido-inflammatory response evidenced by a significant decrease in testicular malondialdehyde, interleukin 1β, interleukin 6, and tumor necrosis factor alpha, and an increase in superoxide dismutase, catalase, glutathione peroxidase, and interleukin 10. These events were associated with a decrease in T2DM-induced increase in XO, UA, and Nf-κb and an increase in T2DM-induced decrease in Nrf2. Also, vitamin D and EX reversed the observed impairment in sperm quality and testicular histology following T2DM-induction. This study revealed the synergistic effect of vitamin D and exercise on T2DM-induced testicular dysfunction.

The Cellular Genesis of Metabolic Syndrome and the Role of Anti-urate Drugs in Hyperuricemia Patients: A Systematic Review

Hyperuricemia results due to the underexcretion of uric acid through kidneys or overproduction due to either intake of purine-rich foods, a high caloric diet, or a decreased activity of purine recycler hypoxanthine-guanine phosphoribosyl transferase (HGPRT). Increased xanthine oxidoreductase (XOR) enzyme activity may contribute to hyperuricemia. Literature provides growing evidence that an independent component that contributes to the development of metabolic syndrome (MetS) and associated comorbidities is hyperuricemia. Thus, precise cellular mechanisms involved during MetS and related comorbidities in hyperuricemia, and the role of anti-urate medicines in these mechanisms require further investigations. We searched online libraries PubMed and Google Scholar for data collection. We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines for literature identification, selection, screening, and determining eligibility to produce unbiased meaningful outcomes. We applied quality assessment tools for the quality appraisal of the studies. And, outcomes were extracted from the selected studies, which revealed the relationship between hyperuricemia and MetS components by causing inflammation, endothelial dysfunction, oxidative stress, and endoplasmic reticulum stress. The selected studies reflected the role of xanthine oxide (XO) inhibitors beyond inhibition. This systematic review concluded that hyperuricemia independently causes inflammation, oxidative stress, endothelial damage, and endoplasmic reticulum stress in patients with hyperuricemia. These mechanisms provide a cellular basis for metabolic syndrome and related comorbidities. In this context, XO inhibitors and their beneficial effects go beyond XOR inhibition to ameliorate these pathological mechanisms.

Potential use of antioxidants for the treatment of chronic inflammatory diseases

The excessive production of various reactive oxidant species over endogenous antioxidant defense mechanisms leads to the development of a state of oxidative stress, with serious biological consequences. The consequences of oxidative stress depend on the balance between the generation of reactive oxidant species and the antioxidant defense and include oxidative damage of biomolecules, disruption of signal transduction, mutation, and cell apoptosis. Accumulating evidence suggests that oxidative stress is involved in the physiopathology of various debilitating illnesses associated with chronic inflammation, including cardiovascular diseases, diabetes, cancer, or neurodegenerative processes, that need continuous pharmacological treatment. Oxidative stress and chronic inflammation are tightly linked pathophysiological processes, one of which can be simply promoted by another. Although, many antioxidant trials have been unsuccessful (some of the trials showed either no effect or even harmful effects) in human patients as a preventive or curative measure, targeting oxidative stress remains an interesting therapeutic approach for the development of new agents to design novel anti-inflammatory drugs with a reliable safety profile. In this regard, several natural antioxidant compounds were explored as potential therapeutic options for the treatment of chronic inflammatory diseases. Several metalloenzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, are among the essential enzymes that maintain the low nanomolar physiological concentrations of superoxide (O2•-) and hydrogen peroxide (H2O2), the major redox signaling molecules, and thus play important roles in the alteration of the redox homeostasis. These enzymes have become a striking source of motivation to design catalytic drugs to enhance the action of these enzymes under pathological conditions related to chronic inflammation. This review is focused on several major representatives of natural and synthetic antioxidants as potential drug candidates for the treatment of chronic inflammatory diseases.

Correlation of uric acid with microalbuminuria in Type-2 diabetic patients with normal creatinine

Objective

To find the correlation of serum uric acid with microalbuminuria in Type-2 diabetic patients with normal creatinine.

Methods

This cross-sectional study was conducted in the Department of Diabetes, Endocrinology and Metabolic diseases, Hayatabad Medical Complex, Peshawar, Pakistan from 1st April, 2022 to 30th September, 2022. Total 160 diabetic patients between the age of 30 and 65 years were enrolled in the study. Type-2 diabetic patients with microalbuminuria between 2.5 and 30 mg/mmol were included. The demographic details of patients were recorded in the questionnaire after taking consent. Fasting Uric acid, lipid profile and glucose along with creatinine and HbA1C were estimated from patient's venous blood samples. Ratio of albumin to creatinine (ACR) in the random spot urine sample was used to detect microalbuminuria.

Results

Out of 160 participants enrolled in the study there were 86 (54%) males and 74 (46%) females with the mean age of 50.15 ± 11.1 years and BMI of 20.93 kg/m2. Ninety six (60%) of the patients had Type-2 DM for less than five years, while remaining 64 (40%) were more than five years diabetic. Mean serum uric acid calculated was 6.85±2.06(mg/dl), while microalbuminuria was calculated as 8.02±0.78 (mg/mmol). The Pearson correlation of serum uric acid and microalbuminuria based on sex and age was statistically significant(p<0.05).

Conclusion

We found that uric acid level was significantly associated with microalbuminuria in people with Type-2 diabetes with normal serum creatinine. Uric acid level can be a potential screening tool for early detection of DKD.

Renal interstitial fibrotic assessment using non-Gaussian diffusion kurtosis imaging in a rat model of hyperuricemia

BACKGROUND

To investigate the feasibility of Diffusion Kurtosis Imaging (DKI) in assessing renal interstitial fibrosis induced by hyperuricemia.

METHODS

A hyperuricemia rat model was established, and the rats were randomly split into the hyperuricemia (HUA), allopurinol (AP), and AP + empagliflozin (AP + EM) groups (n = 19 per group). Also, the normal rats were selected as controls (CON, n = 19). DKI was performed before treatment (baseline) and on days 1, 3, 5, 7, and 9 days after treatment. The DKI indicators, including mean kurtosis (MK), fractional anisotropy (FA), and mean diffusivity (MD) of the cortex (CO), outer stripe of the outer medulla (OS), and inner stripe of the outer medulla (IS) were acquired. Additionally, hematoxylin and eosin (H&E) staining, Masson trichrome staining, and nuclear factor kappa B (NF-κB) immunostaining were used to reveal renal histopathological changes at baseline, 1, 5, and 9 days after treatment.

RESULTS

The HUA, AP, and AP + EM group MKOS and MKIS values gradually increased during this study. The HUA group exhibited the highest MK value in outer medulla. Except for the CON group, all the groups showed a decreasing trend in the FA and MD values of outer medulla. The HUA group exhibited the lowest FA and MD values. The MKOS and MKIS values were positively correlated with Masson's trichrome staining results (r = 0.687, P < 0.001 and r = 0.604, P = 0.001, respectively). The MDOS and FAIS were negatively correlated with Masson's trichrome staining (r = -626, P < 0.0014 and r = -0.468, P = 0.01, respectively).

CONCLUSION

DKI may be a non-invasive method for monitoring renal interstitial fibrosis induced by hyperuricemia.

Triazole derivatives as potential xanthine oxidase inhibitors: Design, enzyme inhibition potential, and docking studies

Considerable ingenuity has been shown in the recent years in the discovery of novel xanthine oxidase (XO) inhibitors that fall outside the purine scaffold. The triazole nucleus has been the cornerstone for the development of many enzyme inhibitors for the clinical management of several diseases, where hyperuricemia is one of them. Here, we give a critical overview of significant research on triazole-based XO inhibitors, with respect to their design, synthesis, inhibition potential, toxicity, and docking studies, done till now. Based on these literature findings, we can expect a burst of modifications on triazole-based scaffolds in the near future by targeting XO, which will treat hyperuricemics, that is, painful conditions like gout that at present are hard to deal with.

Predictive nomogram models for atrial fibrillation in COPD patients: A comprehensive analysis of risk factors and prognosis

The aim of the present study was to identify the independent risk factors and prognostic indicators for atrial fibrillation (AF) in patients with chronic obstructive pulmonary disease (COPD) and to develop predictive nomogram models. This retrospective study included a total of 286 patients with COPD who were admitted to the Second Affiliated Hospital of Guilin Medical College between January 2020 and May 2022. The average age of the patients was 77.11±8.67 years. Based on the presence or absence of AF, the patients were divided into two groups: The AF group (n=87) and the non-AF group (n=199). Logistic regression analysis was conducted to identify variables with significant differences between the two groups. Nomogram models were constructed to predict the occurrence of AF in COPD patients and to assess prognosis. Survival analysis was performed using the Kaplan-Meier method. The follow-up period for the present study extended until April 31, 2023. Survival time was defined as the duration from the date of the interview to the date the participant succumbed or the end of the follow-up period. In the present study, age, uric acid (UA) and left atrial diameter (LAD) were found to be independent risk factors for the development of AF in patients diagnosed with COPD. The stepwise logistic regression analysis revealed that age had an odds ratio (OR) of 1.072 [95% confidence interval (CI): 1.019-1.128; P=0.007], UA had an OR of 1.004 (95% CI: 1.001-1.008; P=0.010) and LAD had an OR of 1.195 (95% CI: 1.098-1.301; P<0.001). Univariate and multivariate Cox regression analysis revealed that LAD and UA were independent prognostic factors for long-term mortality in COPD patients with AF. LAD had a hazard ratio (HR) of 1.104 (95% CI: 1.046-1.165; P<0.001) and UA had an HR of 1.004 (95% CI: 1.000-1.008; P=0.042). Based on these findings, predictive nomogram models were developed for AF in COPD patients, which demonstrated good discrimination ability with an area under the curve of 0.886. The prognostic nomogram for COPD patients with AF also showed good predictive accuracy with a concordance index of 0.886 (95% CI: 0.842-0.930). These models can provide valuable information for risk assessment and prognosis evaluation in clinical practice. Age, UA and LAD are independent risk factors for AF in COPD patients. The developed nomogram models provide a reliable tool for predicting AF in COPD patients and for prognosis assessment.

Xanthine oxidase inhibition study of isolated secondary metabolites from Dolichandrone spathacea (Bignoniaceae): In vitro and in silico approach

Xanthine oxidase (XO) has been widely recognized as a pivotal enzyme in developing hyperuricemia, primarily contributing to the excessive production of uric acid during purine metabolism in the liver. One of the standard treatment approaches involves reducing uric acid levels by inhibiting XO activity. In this study, the leaf extract of Dolichandrone spathacea, traditionally used in folk medicine, was found to inhibit XO activity in the ethyl acetate and butanol fractions at a concentration of 100 µg/mL, their values were 78.57 ± 3.85 % (IC50 = 55.93 ± 5.73 µg/ml) and 69.43 ± 8.68 % (IC50 = 70.17 ± 7.98 µg/ml), respectively. The potential XO inhibitory components were isolated by bioactivity assays and the HR-ESI-MS and NMR spectra system. The main constituents of leaf extracts of Dolichandrone spathacea, six compounds, namely trans-4-methoxycinnamic acid (3), trans-3,4-dimethoxycinnamic acid (4), p-coumaric acid (5), martynoside (6), 6-O-(p-methoxy-E-cinnamoyl)-ajugol (7), and scolymoside (17), were identified as potent XO inhibitors with IC50 values ranging from 19.34 ± 1.63 μM to 64.50 ± 0.94 μM. The enzyme kinetics indicated that compounds 3-5, 7, and 17 displayed competitive inhibition like allopurinol, while compound 6 displayed a mixed-type inhibition. Computational studies corroborated these experimental results, highlighting the interactions between potential metabolites and XO enzyme. The hydrogen bonds played crucial roles in the binding interaction, especially, scolymoside (17) forms a hydrogen bond with Mos3004, exhibited the lowest binding energy (-18.3286 kcal/mol) corresponding to the lowest IC50 (19.34 ± 1.63 μM). Furthermore, nine compounds were isolated for the first time from this plant. In conclusion, Dolichandrone spathacea and its constituents possess the potential to modulate the xanthine oxidase enzyme involved in metabolism.

Piperine Improves Hyperuricemic Nephropathy by Inhibiting URAT1/GLUT9 and the AKT-mTOR Pathway

Uncontrolled hyperuricemia often leads to the development of hyperuricemic nephropathy (HN), characterized by excessive inflammation and oxidative stress. Piperine, a cinnamic acid alkaloid, possesses various pharmacological activities, such as antioxidant and anti-inflammatory effects. In this study, we intended to investigate the protective effects of piperine on adenine and potassium oxonate-induced HN mice and a uric-acid-induced injury model in renal tubular epithelial cells (mRTECs). We observed that treatment with piperine for 3 weeks significantly reduced serum uric acid levels and reversed kidney function impairment in mice with HN. Piperine (5 μM) alleviated uric acid-induced damage in mRTECs. Moreover, piperine inhibited transporter expression and dose-dependently inhibited the activity of both transporters. The results revealed that piperine regulated the AKT/mTOR signaling pathway both in vivo and in vitro. Overall, piperine inhibits URAT1/GLUT9 and ameliorates HN by inhibiting the AKT/mTOR pathway, making it a promising candidate for patients with HN.

Fructose-induced hyperuricaemia - protection factor or oxidative stress promoter?

Accumulating evidence suggests that dietary fructose may play a role in the hyperuricaemia development, but the precise mechanism remains unclear. Hyperuricaemia is characterised by excessive production and deposition of urate crystals, and the metabolism of fructose has been implicated in the elevation of serum urate levels. The association between fructose intake and the risk of hyperuricaemia is explained by the metabolism of fructose in the liver, small intestine, and kidney. Many studies have confirmed the correlation between fructose consumption and an increased risk of developing hyperuricaemia, but more prospective studies to fully elucidate the role of fructose intake in the pathogenesis of hyperuricaemia are needed. It is important to note that maintaining a balanced diet, and lifestyle is crucial when considering fructose intake. Limiting the consumption of products high in added sugars and maintaining a healthy weight can contribute to reducing the risk of hyperuricaemia and associated health complications.

Investigating the nexus of metabolic syndrome, serum uric acid, and dementia risk: a prospective cohort study

BACKGROUND

The global dementia prevalence is surging, necessitating research into contributing factors. We aimed to investigate the association between metabolic syndrome (MetS), its components, serum uric acid (SUA) levels, and dementia risk.

METHODS

Our prospective study comprised 466,788 participants without pre-existing MetS from the UK Biobank. We confirmed dementia diagnoses based on the ICD-10 criteria (F00-03). To evaluate the dementia risk concerning MetS, its components, and SUA levels, we applied Cox proportional hazards models, while adjusting for demographic factors.

RESULTS

Over a median follow-up of 12.7 years, we identified 6845 dementia cases. Individuals with MetS had a 25% higher risk of all-cause dementia (hazard ratio [HR] = 1.25, 95% confidence interval [CI] = 1.19-1.31). The risk increased with the number of MetS components including central obesity, dyslipidemia for high-density lipoprotein (HDL) cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides. Particularly for those with all five components (HR = 1.76, 95% CI = 1.51-2.04). Dyslipidemia for HDL cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides were independently associated with elevated dementia risk (p < 0.01). MetS was further linked to an increased risk of all-cause dementia (11%) and vascular dementia (VD, 50%) among individuals with SUA levels exceeding 400 μmol/L (all-cause dementia: HR = 1.11, 95% CI = 1.02-1.21; VD: HR = 1.50, 95% CI = 1.28-1.77).

CONCLUSIONS

Our study provides robust evidence supporting the association between MetS, its components, and dementia risk. These findings emphasize the importance of considering MetS and SUA levels in assessing dementia risk, offering valuable insights for prevention and management strategies.

The non-causative role of abnormal serum uric acid in intervertebral disc degeneration: A Mendelian randomization study

Background

Intervertebral disc degeneration (IDD) is a common musculoskeletal disorder that contributes significantly to disability and healthcare costs. Serum urate concentration has been implicated in the development of various musculoskeletal conditions. While previous observational studies have suggested an association between the two conditions, it might confound the effect of serum urate concentrations on IDD. This Mendelian randomization (MR) study aimed to investigate the causal relationship between serum urate concentration and IDD.

Methods

We performed a two-sample MR analysis using summary-level data from genome-wide association studies (GWAS) of serum urate concentration (n = 13 585 994 European ancestry) and IDD (n = 16 380 337 European ancestry). Single nucleotide polymorphisms (SNPs) significantly associated with serum urate concentration (p < 5 × 10-8) were selected as instrumental variables. The associations between genetically predicted serum urate concentration and IDD were estimated using the inverse-variance weighted (IVW) method, with sensitivity analyses employing the weighted median, MR-Egger, and MR-PRESSO approaches to assess the robustness of the findings.

Results

In the primary IVW analysis, genetically predicted serum urate concentration was unrelated associated with IDD (odds ratio [OR] = 1.00, 95% confidence interval (CI): 1.00-1.00, p = 0.17)). The results remained consistent across the sensitivity analyses, and no significant directional pleiotropy was detected (MR-Egger intercept: p = 0.15).

Conclusions

This MR study provides evidence that there is no causal relationship between serum urate concentration and IDD. It suggests previous observational associations may be confounded. Serum urate levels are unlikely to be an important contributor to IDD.

Whey Protein Peptide Pro-Glu-Trp Ameliorates Hyperuricemia by Enhancing Intestinal Uric Acid Excretion, Modulating the Gut Microbiota, and Protecting the Intestinal Barrier in Rats

Hyperuricemia (HUA) is a metabolic disorder characterized by an increase in the concentrations of uric acid (UA) in the bloodstream, intricately linked to the onset and progression of numerous chronic diseases. The tripeptide Pro-Glu-Trp (PEW) was identified as a xanthine oxidase (XOD) inhibitory peptide derived from whey protein, which was previously shown to mitigate HUA by suppressing UA synthesis and enhancing renal UA excretion. However, the effects of PEW on the intestinal UA excretion pathway remain unclear. This study investigated the impact of PEW on alleviating HUA in rats from the perspective of intestinal UA transport, gut microbiota, and intestinal barrier. The results indicated that PEW inhibited the XOD activity in the serum, jejunum, and ileum, ameliorated intestinal morphology changes and oxidative stress, and upregulated the expression of ABCG2 and GLUT9 in the small intestine. PEW reversed gut microbiota dysbiosis by decreasing the abundance of harmful bacteria (e.g., Bacteroides, Alloprevotella, and Desulfovibrio) and increasing the abundance of beneficial microbes (e.g., Muribaculaceae, Lactobacillus, and Ruminococcus) and elevated the concentration of short-chain fatty acids. PEW upregulated the expression of occludin and ZO-1 and decreased serum IL-1β, IL-6, and TNF-α levels. Our findings suggested that PEW supplementation ameliorated HUA by enhancing intestinal UA excretion, modulating the gut microbiota, and restoring the intestinal barrier function.

Association between hyperuricemia and long-term mortality in patients with hypertension: results from the NHANES 2001-2018

Objective

The prevalence of hyperuricemia and hypertension is steadily increasing, and these conditions often share common risk factors. This study aimed to investigate the association among hyperuricemia, hypertension, and all-cause mortality in a nationally representative U.S. population.

Methods

Data for 38,644 participants were obtained from the National Health and Nutrition Examination Survey (NHANES) 2001-2018. Hyperuricemia was defined as a serum urate concentration >420 μmol/L in men and >360 μmol/L in women. Information regarding death outcomes was obtained through the National Death Index (NDI). Multivariate logistic regression, Cox proportional hazards models, and restricted cubic spline (RCS) analyses were used to evaluate the association between hyperuricemia and hypertension in all included participants, as well as long-term mortality in patients with hypertension.

Results

Among all participants, 6,956 (18.0%) had hyperuricemia, while 31,688 (82.0%) had nonhyperuricemia. According to the adjusted models, hyperuricemia was more strongly associated with hypertension (OR 2.04) than was non-hyperuricemia. During the median follow-up period of 78 months, both hyperuricemia (HR 1.48, 1.95) and hypertension (HR 1.42, 1.69) independently associated with the increased risk of all-cause mortality and cardiovascular mortality, respectively, with the highest risk observed in those with both conditions (HR 1.87, 2.82). RCS analyses revealed nonlinear J-shaped (for hypertension) and U-shaped (for both all-cause and cardiovascular mortality) relationships with serum urate levels.

Conclusions

Hyperuricemia is associated with an elevated risk of developing hypertension compared to non-hyperuricemia. Among patients with hypertension, those with hyperuricemia are more likely to experience all-cause and cardiovascular mortality during long-term follow-up.

Association between gout and the risk of osteoporosis and fractures: a meta-analysis

OBJECTIVE

The relationship between gout and osteoporosis is poorly clarified, and the association between gout and fractures incidence remains controversial. Hence, in the present study, we aimed to comprehensively evaluate the available literature to elucidate whether gout is associated with an increased risk of both osteoporosis and fractures.

MATERIALS AND METHODS

We conducted an exhaustive search of pertinent literature published until 20 March 2023, in well-recognized databases, namely Medline, Embase and Cochrane Library, focusing on examining the association between gout and the risk of osteoporosis or fracture. Meta-analysis was performed to aggregate the relative risks (RR) using random- or fixed-effects models. Sensitivity analyses were conducted iteratively, whereby each study was removed sequentially to gauge its impact on the overall outcome. Publication bias was assessed using Egger's and Begg's tests. This study was registered with PROSPERO (registry number: CRD42022376822).

RESULTS

Herein, we included 10 observational studies comprising a total of 1,606,095 participants. An independent population sample of four studies validated the significant association between gout and osteoporosis (RR = 1.25, 95% confidence interval [CI] 1.05-1.48), with the results demonstrating robustness. However, our analysis did not detect any association between gout and fracture risk when compared with the control group (RR = 1.09, 95%CI 0.99-1.19), along with high heterogeneity (p for heterogeneity = 0.000; I2 = 79.7%). Further subgroup analysis revealed that gout is positively associated with fracture risk in the Chinese population (RR = 1.17, 95%CI 1.14-1.21), with no evidence of heterogeneity (p for heterogeneity = 0.420; I2 = 0.00%).

CONCLUSION

Our meticulous evaluation of the available literature indicates that gout has no discernible impact on fracture incidence, although it is positively associated with an enhanced risk of osteoporosis. Therefore, it is imperative to prioritize preventive measures to prevent osteoporotic complications in individuals diagnosed with gout.

Inhibitors of gastric acid secretion increase oxidative stress and matrix metalloproteinase-2 activity leading to vascular remodeling

The use of inhibitors of gastric acid secretion (IGAS), especially proton pump inhibitors (PPI), has been associated with increased cardiovascular risk. While the mechanisms involved are not known, there is evidence supporting increased oxidative stress, a major activator of matrix metalloproteinases (MMP), as an important player in such effect. However, there is no study showing whether other IGAS such as histamine H2-receptor blockers (H2RB) cause similar effects. This study aimed at examining whether treatment with the H2RB ranitidine promotes oxidative stress resulting in vascular MMP activation and corresponding functional and structural alterations in the vasculature, as compared with those found with the PPI omeprazole. Male Wistar rats were treated (4 weeks) with vehicle (2% tween 20), omeprazole (10 mg/Kg/day; i.p.) or ranitidine (100 mg/Kg/day; gavage). Then the aorta was collected to perform functional, biochemical, and morphometric analysis. Both ranitidine and omeprazole increased gastric pH and oxidative stress assessed in situ with the fluorescent dye dihydroethidium (DHE) and with lucigenin chemiluminescence assay. Both IGAS augmented vascular activated MMP-2. These findings were associated with aortic remodeling (increased media/lumen ratio and number of cells/μm2). Both IGAS also impaired the endothelium-dependent relaxation induced by acetylcholine (isolated aortic ring preparation). This study provides evidence that the H2RB ranitidine induces vascular dysfunction, redox alterations, and remodeling similar to those found with the PPI omeprazole. These findings strongly suggest that IGAS increase oxidative stress and matrix metalloproteinase-2 activity leading to vascular remodeling, which helps to explain the increased cardiovascular risk associated with the use of those drugs.

Poor serum uric acid control increases risk for developing hypertension: a retrospective cohort study in China

Background

Serum uric acid (SUA) has been suggested as a contributor of hypertension. However, reports on the relationship between changes in SUA and hypertension are limited. Hence, we aimed to investigate the potential impact of SUA, especially its change over time, on hypertension incidence.

Methods

This dynamic cohort included 6052 participants without hypertension at baseline. Participants were categorized into six grades based on whether baseline SUA was high and whether changes in SUA progressed to hyperuricemia or decreased to normal levels. Grades 1 to 6 represented the participants' SUA control from best to worst. Logistic regression and restricted cubic spline (RCS) models were used to explore the association of the grades of SUA control and hypertension incidence.

Results

During a median follow-up of 6 years, 2550 (42.1%) participants developed hypertension. After adjusting confounding factors, compared to grade 1 with the best control of SUA, the odds ratios for grades 2 to 6 with worse control were 1.347 (1.109-1.636), 1.138 (0.764-1.693), 1.552 (1.245-1.934), 1.765 (1.170-2.663), and 2.165 (1.566-2.993), respectively. RCS indicated a linear correlation between the risk of hypertension and changes in SUA, and an elevated risk in participants with baseline hyperuricemia. Subgroup analyses showed that grades of SUA control had an interaction with systolic (P = 0.003) and diastolic blood pressure (P < 0.001). Sensitivity analyses further determined the robustness of the result that participants with poor SUA control have a higher risk of developing hypertension.

Conclusion

Poor SUA control, an increase in SUA over time, rises the risk of developing hypertension regardless of whether the initial SUA is normal or not. Initial hyperuricemia will exacerbate this risk. Effective SUA control should be an important measure for primary prevention of hypertension.

Association of Uric Acid to Creatinine Ratio with Metabolic Dysfunction-Associated Fatty Liver in Non-Obese Individuals Without Type 2 Diabetes Mellitus

Introduction

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common chronic liver disease, which is usually associated with type 2 diabetes mellitus (T2DM) and obesity. However, the incidence of MALFD in non-obese individuals without T2DM is increasing, and the pathogenesis is unclear. Serum uric acid to creatinine ratio (sUA/Cr) can reflect overall metabolic status. This study aims to observe the association between sUA/Cr and MAFLD in non-obese individuals without T2DM.

Methods

A total of 21,996 individuals were included in this study. The subjects were divided into four subgroups: non-obese patients without T2DM, obese patients without T2DM, non-obese patients with T2DM, and obese patients with T2DM. Logistic regression analyzed the correlation between sUA/Cr and MAFLD subgroups. Receiver operating characteristics analyzed the predictive value of sUA/Cr for MAFLD subgroups. The stratified analyses by sex and age were performed.

Results

Non-obese MAFLD individuals without T2DM had higher sUA/Cr levels than their counterparts. sUA/Cr was significantly correlated positively with MAFLD in non-obese patients. Similar results were observed in both males and females and in populations at all age stages (all p<0.01). sUA/Cr was capable of discriminating MAFLD in non-obese individuals without T2DM (AUC: 0.667), especially for patients over 60 years old (AUC: 0.704).

Conclusion

The sUA/Cr ratio was correlated with MAFLD in non-obese patients without T2DM. The predictive value of sUA/Cr for MAFLD was observed. Hence, the sUA/Cr ratio might be given more concern for the risk of MAFLD in non-obese individuals without T2DM.

SNHG12/NFYC-AS1 Acted as the Sponge for hsa-miR-199a-5p to Promote the Expression of S100A8/S100A7/XDH and was Involved in the Progression of Diabetic Foot Ulcers

Traditional Chinese medicine has been used to treat diabetic foot ulcer (DFU) for a long time. However, the underlying mechanism of Radix arnebiae seu lithospermi ointment (RAS-ointment) has not been revealed. Effects of RAS-ointment treatment were observed in DFU patients. The endogenous competitive RNA mechanism was constructed based on micro-array sequencing and bioinformatics analysis. RT-PCR was used to detected the expression of genes in DFU ulcerated skins and non-ulcerated skins. Dual luciferase and RT-PCR experiments were used to investigate the endogenous competitive RNA mechanism. Based on micro-array sequencing and bioinformatics analysis, we found that SNHG12/NFYC-AS1, hsa-miR-199a-5p and S100A8/S100A7/XDH might form an endogenous competitive RNA mechanism. RT-PCR assay shown that SNHG12, NFYC-AS1, S100A8, S100A7 and XDH were significantly up-regulated, while hsa-miR-199a-5p was significantly down-regulated in DFU ulcerated skins (N = 10) compared with non-ulcerated skins (N = 10). Dual luciferase and RT-PCR experiments showed that SNHG12 or NFYC-AS1 up-regulated the expression of S100A8, S100A7 and XDH by inhibiting hsa-miR-199a-5p in a direct binding way. After 35 days of RAS-ointment treatment, the wound healing of DFU patients was substantially improved and the expression of S100A7 and XDH were reduced expression in DFU patients. In addition, the monomer composition of RAS-ointment, 49070_FLUKA or auraptenol inhibited the expression of S100A7 and XDH in Te317.sk cells. In conclusion, RAS-ointment may be used as an adjunctive therapy for DFU patients.

Comprehensive analysis of the relationship between xanthine oxidoreductase activity and chronic kidney disease

Chronic kidney disease (CKD) is a common disease that seriously endangers human health. However, the potential relationship between xanthine oxidoreductase (XOR) activity and CKD remains unclear. In this study, we used clinical data, CKD datasets from the Gene Expression Omnibus database, and untargeted metabolomics to explain the relationship between XOR activity and CKD. First, XOR activity showed high correlation with the biomarkers of CKD, such as serum creatinine, blood urea nitrogen, uric acid, and estimated glomerular filtration rate. Then, we used least absolute shrinkage and selection operator logical regression algorithm and random forest algorithm to screen CKD molecular markers from differentially expressed genes, and the results of qRT-PCR of XDH, KOX-1, and ROMO1 were in accordance with the results of bioinformatics analyses. In addition, untargeted metabolomics analysis revealed that the purine metabolism pathway was significantly enriched in CKD patients in the simulated models of kidney fibrosis.

Potential antioxidative and anti-hyperuricemic components in Rodgersia podophylla A. Gray revealed by bio-affinity ultrafiltration with SOD and XOD

Rodgersia podophylla A. Gray (R. podophylla) is a traditional Chinese medicine with various pharmacological effects. However, its antioxidant and anti-hyperuricemia components and mechanisms of action have not been explored yet. In this study, we first assessed the antioxidant potential of R. podophylla with 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric ion reducing antioxidant power (FRAP) assays. The results suggested that the ethyl acetate (EA) fraction of R. podophylla not only exhibited the strongest DPPH, ABTS radical scavenging and ferric-reducing activities, but also possessed the highest total phenolic and total flavonoid contents among the five fractions. After that, the potential superoxide dismutase (SOD) and xanthine oxidase (XOD) ligands from the EA fraction were quickly screened and identified through the bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS). Accordingly, norbergenin, catechin, procyanidin B2, 4-O-galloylbergenin, 11-O-galloylbergenin, and gallic acid were considered to be potential SOD ligands, while gallic acid, 11-O-galloylbergenin, catechin, bergenin, and procyanidin B2 were recognized as potential XOD ligands, respectively. Moreover, these six ligands effectively interacted with SOD in molecular docking simulation, with binding energies (BEs) ranging from -6.85 to -4.67 kcal/mol, and the inhibition constants (Ki) from 9.51 to 379.44 μM, which were better than the positive controls. Particularly, catechin exhibited a robust binding affinity towards XOD, with a BE value of -8.54 kcal/mol and Ki value of 0.55 μM, which surpassed the positive controls. In conclusion, our study revealed that R. podophylla possessed remarkable antioxidant and anti-hyperuricemia activities and that the UF-LC-MS method is suitable for screening potential ligands for SOD and XOD from medicinal plants.

The effect of lipid metabolism disorder on patients with hyperuricemia using Multi-Omics analysis

A multiomics study was conducted to investigate how lipid metabolism disorders affect the immune system in Xinjiang patients with hyperuricemia. The serum of 60 healthy individuals and 60 patients with hyperuricemia was collected. This study used LC-MS and HPLC to analyze differential lipid metabolites and enrichment pathways. It measured levels of immune factors tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), carnitine palmitoyltransferase-1 (CPT1), transforming growth factor-β1 (TGF-β1), glucose (Glu), lactic acid (LD), interleukin 10 (IL-10), and selenoprotein 1 (SEP1) using ELISA, as well as to confirm dysregulation of lipid metabolism in hyperuricemia. 33 differential lipid metabolites were significantly upregulated in patients with hyperuricemia. These lipid metabolites were involved in arachidonic acid metabolism, glycerophospholipid metabolism, linoleic acid metabolism, glycosylphosphatidylinositol (GPI)-anchor biosynthesis, and alpha-Linolenic acid metabolism pathways. Moreover, IL-10, CPT1, IL-6, SEP1, TGF-β1, Glu, TNF-α, and LD were associated with glycerophospholipid metabolism. In patients with hyperuricemia of Han and Uyghur nationalities, along with healthy individuals, significant differences in CPT1, TGF-β1, Glu, and LD were demonstrated by ELISA (P < 0.05). Furthermore, the levels of SEP1, IL-6, TGF-β1, Glu, and LD differed considerably between groups of the same ethnicity (P < 0.05). It was found that 33 kinds of lipid metabolites were significantly different in patients with hyperuricemia, which mainly involved 5 metabolic pathways. According to the results of further studies, it is speculated that CPT1, TGF-β1, SEP1, IL-6, Glu and LD may increase fatty acid oxidation and mitochondrial oxidative phosphorylation in patients through glycerophospholipid pathway, reduce the rate of glycolysis, and other pathways to change metabolic patterns, promote different cellular functions, and thus affect the disease progression in patients with hyperuricemia.

Association between elevated serum uric acid levels and high estimated glomerular filtration rate with reduced risk of low muscle strength in older people: a retrospective cohort study

BACKGROUND

We aimed to investigate the interaction between serum uric acid (SUA) levels with estimated glomerular filtration rate (eGFR) to low muscle strength (LMS) among older people in China.

METHODS

Cohort data were obtained from China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 2015. A total of 2,822 community-dwelling adults aged 60 and above were enrolled for the follow-up. Serum uric acid was collected after 8 h of fasting, and handgrip strength was measured with a dynamometer. eGFR was calculated with an equation based on the Chinese population. A generalized additive model was employed for interaction analysis and progressively adjusted confounders.

RESULTS

During the follow-up, a total of 659 individuals were excluded due to the lack of grip strength data, leaving 2,163 participants for analysis. Despite the protective effect of high uric acid against low muscle strength, especially in older females, it is not statistically significant (OR = 0.69, 95%CI = 0.45-1.04, P = 0.075). Following the progressive adjustment of covariates, the association between higher eGFR and elevated SUA levels remained statistically significant in females, showing a reduced odds ratio with low muscle strength (OR = 0.82, 95%CI = 0.70-0.97, P = 0.021). However, this trend was not observed in male participants.

CONCLUSIONS

This Chinese population-based cohort study suggests that among older females, a higher serum uric acid level combined with a higher estimated glomerular filtration rate is linked to a reduced risk of low muscle strength. This implies that the relationship between high serum uric acid levels and the risk of low grip strength might differ by gender.

Gout/hyperuricemia reduces the risk of Alzheimer's disease: A meta-analysis based on latest evidence

OBJECTIVE

Previous studies have found the potential role of gout or hyperuricemia in subsequent development of Alzheimer's disease (AD) but reported inconsistent results. We conducted the current meta-analysis to evaluate whether an association exists between gout/ hyperuricemia and AD.

METHODS

We systematically searched PubMed and EMBASE for the published cohort studies that measured the risk of AD in subject with gout/ hyperuricemia up to May 20, 2023. Data extraction was employed by two authors independently. Rev Man 5.3 and Stata 15.0 software were used to calculate the relative ratio (RR) or hazard ratio (HR) for including studies. Subgroup analysis was performed to assess the sources of heterogeneity. A random-effects model was adopted when heterogeneity was present. The funnel plot, Begg's test, and and Egger's test were used to assess publication bias.

RESULTS

After rigorous screening, seven eligible studies were included in the final analyses. Pooled results indicated that gout or hyperuricemia decreases the risk of AD (RR: 0.69, 95% CI: 0.64∼0.72), with a high heterogeneity of 93%. Subgroup analyses showed that regional distribution was the source of heterogeneity. Egger's and Begg's tests as well as visual inspection of funnel plot suggested no publication bias in the studies.

CONCLUSION

The findings suggested that gout or hyperuricemia might have a protective effect against AD. This negative correlation should be verified by more cohort studies due to the existence of substantial heterogeneity.

Serum Uric Acid to Creatinine Ratio and Risk of Metabolic Syndrome in Patients with Overweight/Obesity

Purpose

Metabolic syndrome (MetS) is a rising global concern with an increasing prevalence. This study aimed to evaluate the relationship between serum uric acid to creatinine ratio (SUA/Cr) and MetS in adults with overweight/obesity in China.

Patients and Methods

We conducted a cross-sectional study comprising 4699 participants with overweight/obesity who underwent physical examinations. Their serum levels of various components, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), fasting plasma glucose (FPG), creatinine (Cr), and uric acid (UA) were measured. Renal function-normalized SUA was calculated using SUA/Cr. Logistic regression analysis was employed to investigate the association between SUA/Cr and MetS in adults with overweight/obesity.

Results

SUA/Cr levels were lower in non-MetS participants (OR: 2.159, 95% CI: 1.82 to 2.56; p < 0.001), and tended to rise with the increasing number of MetS components. Additionally, elevated SUA/Cr levels were associated with a higher risk of hypertension, hyperglycemia, and dyslipidemia.

Conclusion

SUA/Cr levels were significantly associated with MetS and its components in Chinese adults with overweight/obesity.

Phosphatidylserine decarboxylase downregulation in uric acid‑induced hepatic mitochondrial dysfunction and apoptosis

The molecular mechanisms underlying uric acid (UA)-induced mitochondrial dysfunction and apoptosis have not yet been elucidated. Herein, we investigated underlying mechanisms of UA in the development of mitochondrial dysfunction and apoptosis. We analyzed blood samples of individuals with normal UA levels and patients with hyperuricemia. Results showed that patients with hyperuricemia had significantly elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, which may indicate liver or mitochondrial damage in patients with hyperuricemia. Subsequently, lipidomic analysis of mouse liver tissue mitochondria and human liver L02 cell mitochondria was performed. Compared with control group levels, high UA increased mitochondrial phosphatidylserine (PS) and decreased mitochondrial phosphatidylethanolamine (PE) levels, whereas the expression of mitochondrial phosphatidylserine decarboxylase (PISD) that mediates PS and PE conversion was downregulated. High UA levels also inhibited signal transducer and activator of transcription 3 （STAT3） phosphorylation as well as mitochondrial respiration, while inducing apoptosis both in vivo and in vitro. Treatment with allopurinol, overexpression of PISD, and lyso-PE (LPE) administration significantly attenuated the three above-described effects in vitro. In conclusion, UA may induce mitochondrial dysfunction and apoptosis through mitochondrial PISD downregulation. This study provides a new perspective on liver damage caused by hyperuricemia.

Exposure to Cadmium, Lead, Mercury, and Arsenic and Uric Acid Levels: Results from NHANES 2007-2016

Mechanisms underlying abnormal uric acid (UA) levels from exposure to toxic metals/metalloids have not been not fully elucidated, especially in the context of mixtures. The aim was to identify major toxic metals/metalloids that affected UA levels with a mixture exposure concept in the association model. From 2007-2016 National Health and Nutrition Examination Survey (NHANES), 4794 adults were involved. Serum UA (SUA) and SUA to serum creatinine ratio (SUA/SCr) were used to estimate the UA levels, and cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) in the blood and/or urine were evaluated in the study. We assessed the associations between toxic metals and UA levels using linear regression and Bayesian kernel machine regression (BKMR). The median [P₂₅, P₇₅] SUA/SCr and SUA level were 6.22 [5.27, 7.32] and 0.83 [0.72, 0.98], respectively. There was no difference for SUA/SCr by gender (men, 6.25 [5.39, 7.29]; women, 6.17 [5.17, 7.36], P = 0.162), but men had higher SUA than women (men, 0.95 [0.85, 1.05]; women, 0.72 [0.64, 0.82], P < 0.001). Blood Pb (β_men = 0.651 and β_women = 1.014) and urinary Cd (β_men = 0.252 and β_women = 0.613) were positively associated with SUA/SCr, and urinary Pb (β_men =  - 0.462 and β_women =  - 0.838) was inversely associated with SUA/SCr in multivariate linear regression analysis. However, urinary As (β_men = 0.351) was positively associated with SUA/SCr only in men. BKMR showed that higher concentrations of exposure to a mixture of toxic metals were positively associated with higher UA levels, where Cd, Pb, and urinary As contributed most to the overall mixture effect in men, while Pb and urinary Cd in women. Our study provided the first evidence that mixtures of metals are associated with the UA levels. Increased concentrations of metals, mainly blood Pb, urinary Cd, and As (only in men) may increase the level of UA.

Cachrys L. Genus: A Comprehensive Review on Botany, Phytochemistry and Biological Properties

The Cachrys L. genus belongs to the Apiaceae family and it is widely distributed in the Mediterranean basin, with plant species being endemic to southern Europe, Asia, and northern Africa. Different studies, focused on the phytochemical composition of Cachrys spp. and the biological properties of their phytocomplexes, have been reported. These works mostly focused on the essential oils obtained from these plants, and pointed out that Cachrys species are a rich source of coumarins, mainly furanocoumarins. Other phytochemicals, such as terpenes, fatty acids, phytosterols, and flavonoids have been also identified. Moreover, a number of biological properties such as antioxidant, antimicrobial, anti-inflammatory, cytotoxic, and photocytotoxic effects have been assessed. Nevertheless, a review of the chemical and pharmacological properties of this genus is not available in the literature. The aim of this paper is to provide an overview of the reports concerning the identified phytochemicals and the biological effects reported for Cachrys spp., and to offer a comprehensive understanding of the potential of this genus as a source of bioactive compounds. The current taxonomy, the traditional uses, and the toxicological aspects of plants belonging to this genus are also reported, and the future research directions are discussed.

Oxidative Stress Underpins Clinical, Social, and Genetic Risk Factors for Atherosclerotic Cardiovascular Disease

Background

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death worldwide and is poorly predicted with current risk estimation tools. The biological mechanisms relating ASCVD risk factors to oxidative stress (OS) and how this accumulates ASCVD risk are misunderstood.

Purpose

To develop a comprehensive conceptual model explaining how expanded clinical, social, and genetic ASCVD risk factors accumulate ASCVD risk through OS.

Conclusions

OS (primarily from excess reactive oxygen species) and inflammation are present along the entire ASCVD pathophysiologic continuum. An expanded list of clinical and social ASCVD risk factors (including hypertension, obesity, diabetes, kidney disease, inflammatory diseases, substance use, poor nutrition, psychosocial stress, air pollution, race, and genetic ancestry) influence ASCVD largely through increased OS. Many risk factors exert a positive feedback mechanism to increase OS. One genetic risk factor, haptoglobin (Hp) genotype, is associated with higher ASCVD risk in diabetes and hypothesized to do the same in those with insulin resistance due to the Hp 2-2 genotype increasing OS.

Implications

Understanding the biological mechanisms of OS informs how these ASCVD risk factors relate to each other and compound ASCVD risk. Individualized ASCVD risk estimation should include a comprehensive, holistic perspective of risk factors to better address the clinical, social, and genetic influences of OS. Preventing and reducing OS is key to preventing ASCVD development or progression.

Growth Factors Upregulated by Uric Acid Affect Guanine Deaminase-Induced Melanogenesis

Uric acid produced by guanine deaminase (GDA) is involved in photoaging and hyperpigmentation. Reactive oxygen species (ROS) generated by uric acid plays a role in photoaging. However, the mechanism by which uric acid stimulates melanogenesis in GDA-overexpressing keratinocytes is unclear. Keratinocyte-derived paracrine factors have been identified as important mechanisms of ultraviolet-induced melanogenesis. Therefore, the role of paracrine melanogenic growth factors in GDA-induced hypermelanosis mediated by uric acid was examined. The relationships between ROS and these growth factors were examined. Primary cultured normal keratinocytes overexpressed with wild type or mutant GDA and those treated with xanthine or uric acid in the presence or absence of allopurinol, H₂O₂, or N-acetylcysteine (NAC) were used in this study. Intracellular and extracellular bFGF and SCF levels were increased in keratinocytes by wild type, but not by loss-of-function mutants of GDA overexpression. Culture supernatants from GDA-overexpressing keratinocytes stimulated melanogenesis, which was restored by anti-bFGF and anti-SCF antibodies. Allopurinol treatment reduced the expression levels of bFGF and SCF in both GDA-overexpressing and normal keratinocytes exposed to exogenous xanthine; the exogenous uric acid increased their expression levels. H₂O₂-stimulated tyrosinase expression and melanogenesis were restored by NAC pretreatment. However, H₂O₂ or NAC did not upregulate or downregulate bFGF or SCF, respectively. Overall, uric acid could be involved in melanogenesis induced by GDA overexpression in keratinocytes via bFGF and SCF upregulation not via ROS generation.

Association between serum uric acid level and bone mineral density at multiple skeletal sites in middle-aged and elderly men: a cross-sectional study of a healthy population in Taiwan

This study revealed that serum uric acid (sUA) levels were not associated with bone mineral density (BMD) at different skeletal sites in middle-aged and elderly men, even adjusting for confounding variables. Nevertheless, a positive association was only found between sUA levels and BMD at all skeletal sites in the normal BMI group.

INTRODUCTION

Previous studies have reported an association between serum uric acid (sUA) levels and bone mineral density (BMD). However, their findings are controversial and limited to adult men in the general population. This study was aimed at examining the association between sUA levels and BMD at multiple skeletal sites in middle-aged and elderly men.

METHODS

A cross-sectional analysis of BMD at different skeletal sites and sUA levels was conducted on 918 men (age: 50.83 ± 7.95) using data from the Ditmanson Research Database. The participants were categorized into four groups based on quartiles of the sUA level, and BMD were assessed using dual-energy X-ray absorptiometry. Multivariate linear regression models were utilized to investigate the association between sUA levels and BMD. Further, subgroup analyses were performed.

RESULTS

After adjusting for potential confounding factors, sUA as a continuous variable was significantly associated with BMD at the femoral neck only (β, 95% confidence interval: 0.007 [0.001-0.013]). However, in the categorical analysis, no significant differences were detected in terms of BMD at different skeletal sites across the different sUA quartile groups. Moreover, if the body mass index (BMI) was < 24 kg/m² for each unit increase in sUA level, the spine, femoral neck, and total hip BMD increased by 0.014, 0.013, and 0.015 g/cm², respectively.

CONCLUSION

The sUA level was not associated with BMD at different skeletal sites in middle-aged and elderly men. Nevertheless, a positive association was only found between sUA levels and BMD at all skeletal sites in the normal weight group.

The critical issue linking lipids and inflammation: Clinical utility of stopping oxidative stress

The formation of an atheroma begins when lipoproteins become trapped in the intima. Entrapped lipoproteins become oxidized and activate the innate immune system. This immunity represents the primary association between lipids and inflammation. When the trapping continues, the link between lipids and inflammation becomes chronic and detrimental, resulting in atherosclerosis. When entrapment ceases, the association between lipids and inflammation is temporary and healthy, and the atherogenic process halts. Therefore, the link between lipids and inflammation depends upon lipoprotein retention in the intima. The entrapment is due to electrostatic forces uniting apolipoprotein B to polysaccharide chains on intimal proteoglycans. The genetic transformation of contractile smooth muscle cells in the media into migratory secretory smooth muscle cells produces the intimal proteoglycans. The protein, platelet-derived growth factor produced by activated platelets, is the primary stimulus for this genetic change. Oxidative stress is the main stimulus to activate platelets. Therefore, minimizing oxidative stress would significantly reduce the retention of lipoproteins. Less entrapment decreases the association between lipids and inflammation. More importantly, it would halt atherogenesis. This review will analyze oxidative stress as the critical link between lipids, inflammation, and the pathogenesis of atherosclerosis. Through this perspective, we will discuss stopping oxidative stress to disrupt a harmful association between lipids and inflammation. Numerous therapeutic options will be discussed to mitigate oxidative stress. This paper will add a new meaning to the Morse code distress signal SOS-stopping oxidative stress.

Extracellular vesicles isolated from hyperuricemia patients might aggravate airway inflammation of COPD via senescence-associated pathway

BACKGROUNDS

Chronic obstructive pulmonary disease (COPD) is a major health issue resulting in significant mortality worldwide. Due to the high heterogeneity and unclear pathogenesis, the management and therapy of COPD are still challenging until now. Elevated serum uric acid(SUA) levels seem to be associated with the inflammatory level in patients with COPD. However, the underlying mechanism is not yet clearly established. In the current research, we aim to elucidate the effect of high SUA levels on airway inflammation among COPD patients.

METHODS

Through bioinformatic analysis, the common potential key genes were determined in both COPD and hyperuricemia (HUA) patients. A total of 68 COPD patients aged 50-75-year were included in the study, and their clinical parameters, including baseline characteristics, lung function test, as well as blood chemistry test were recorded. These parameters were then compared between the COPD patients with and without HUA. Hematoxylin & Eosin (HE), immunofluorescence (IF), and Masson trichrome staining were performed to demonstrate the pathological changes in the lung tissues. Furthermore, we isolated extracellular vesicles (EVs) from plasma, sputum, and bronchoalveolar lavage fluid (BALF) samples and detected the expression of inflammatory factor (Interleukin-6 (IL-6), IL-8 and COPD related proteases (antitrypsin and elastase) between two groups. Additionally, we treated the human bronchial epithelial (HBE) cells with cigarette smoke extract (CSE), and EVs were derived from the plasma in vitro experiments. The critical pathway involving the relationship between COPD and HUA was eventually validated based on the results of RNA sequencing (RNA-seq) and western blot (WB).

RESULTS

In the study, the COPD patients co-existing with HUA were found to have more loss of pulmonary function compared with those COPD patients without HUA. The lung tissue samples of patients who had co-existing COPD and HUA indicated greater inflammatory cell infiltration, more severe airway destruction and even fibrosis. Furthermore, the high SUA level could exacerbate the progress of airway inflammation in COPD through the transfer of EVs. In vitro experiments, we determined that EVs isolated from plasma, sputum, and BALF played pivotal roles in the CSE-induced inflammation of HBE. The EVs in HUA patients might exacerbate both systemic inflammation and airway inflammatory response via the senescence-related pathway.

CONCLUSION

The pulmonary function and clinical indicators of COPD patients with HUA were worse than those without HUA, which may be caused by the increased airway inflammatory response through the EVs in the patient's peripheral blood. Moreover, it might mediate the EVs via senescence-related pathways in COPD patients with HUA.

Association between metabolic syndrome and uric acid: a systematic review and meta-analysis

This systematic review and meta-analysis aim to provide the best evidence on the association between metabolic syndrome (MetS) and uric acid (UA) by determining the size of the effect of this biomarker on MetS. The review protocol is registered with PROSPERO (CRD42021231124). The search covered the PubMed and Scopus databases. Methodological quality was assessed with the STROBE tool, overall risk of bias with RevMan (Cochrane Collaboration) and quality of evidence with Grade Pro. Initially, 1582 articles were identified. Then, after excluding duplicates and reviewing titles and abstracts, 1529 articles were excluded from applying the eligibility criteria. We included 43 papers (56 groups) comparing UA concentrations between subjects 91,845 with MetS and 259,931 controls. Subjects with MetS had a higher mean UA of 0.57 mg/dl (95% CI 0.54-0.61) (p < 0.00001). Given the heterogeneity of the included studies, the researchers decided to perform subgroups analysis. Men with MetS have a higher UA concentration mg/dl 0.53 (95% CI 0.45-0.62, p < 0.00001) and women with MetS 0.57 (95% CI 0.48-0.66, p < 0.00001) compared to subjects without MetS. Assessment of UA concentration could provide a new avenue for early diagnosis of MetS, as a new biomarker and the possibility of new therapeutic targets.

Uric Acid as a Risk Factor for Cardiovascular Diseases

Recently, hyperuricemia and its association with cardiovascular disease have been receiving more and more attention. The article talks about the role of uric acid in the body, the reasons for its increase and the impact of elevated uric acid levels on the cardiovascular system. The mechanisms of influence of hyperuricemia on the development and progression of cardiovascular diseases are presented. Medicinal and non-drug ways to reduce the level of uric acid in the blood are considered. From non-drug methods, attention is focused on the hypopurine diet, adequate drinking regimen and normalization of body weight. Separately, the effect on the level of uric acid of various drugs used in clinical practice is considered. In the light of current clinical guidelines, the issue of the need to prescribe drug therapy for asymptomatic hyperuricemia is discussed.

Prebiotic Chemistry: The Role of Trimetaphosphate in Prebiotic Chemical Evolution

Life’s origins have always been a scientific puzzle. Understanding the production of biomolecules is crucial for understanding the evolution of life on Earth. Numerous studies on trimetaphosphate have been conducted in the field of prebiotic chemistry. However, its role in prebiotic chemistry has been documented infrequently in the review literature. The goal of this thesis is to review the role of trimetaphosphate in the early Earth’s biomolecule synthesis and phosphorylation. Additionally, various trimetaphosphate-mediated reaction pathways are discussed, as well as the role of trimetaphosphate in prebiotic chemistry. Finally, in our opinion, interactions between biomolecules should be considered in prebiotic synthesis scenarios since this may result in some advances in subsequent research on this subject. The research establishes an essential and opportune foundation for an in-depth examination of the “mystery of life".

In vitro enzyme inhibition and in vivo anti-hyperuricemic potential of eugenol: An experimental approach

Xanthine oxidase (XO) was accountable for the uric acid synthesis in the body and is considered as a prominent therapeutic target in urate lowering treatment. Eugenol is a natural compound commonly found in the clove, cinnamon etc. and have various biological activities. This study was designed to examine the anti-hyperuricemic effect of eugenol by in vitro and in vivo studies. Potassium oxonate (PO) was used to induce hyperuricemia in Wistar rats. Different doses of eugenol (1.25, 2.5 and 5mg/kg bwt orally) were used for the treatment and various biological function markers (renal, hepatic and hematological) were analyzed. The IC₅₀ value obtained for eugenol was 3.51 ± 0.002 μM. The kinetic studies revealed that the eugenol exhibited a mixed type of inhibition. Abnormality in the levels of various biological function markers were observed in the PO treated rats. Upon the eugenol treatment, those biological function markers were retained near to its normal values. The study proved the anti-hyperuricemic potential of eugenol against the PO induced hyperuricemia model.

Serum Uric Acid Levels and Cardiometabolic Profile in Middle-Aged, Treatment-Naïve Hypertensive Patients

INTRODUCTION

Uric acid (UA) is a risk factor associated with cardiometabolic diseases. However, the appropriate threshold of UA remains a matter of controversy.

AIM

To assess whether slightly increased UA levels have any significance in middle-aged, treatment-naïve persons with new-onset hypertension.

METHODS

In this cross-sectional study we recruited middle-aged participants with new-onset hypertension who were treatment-naïve. Subjects below (Group 1) and above the median UA levels (Group 2) were compared regarding clinical and laboratory characteristics that are implicated in cardiovascular and renal risk. The study population consisted of 369 persons (mean age 48.4±10 years) with median UA of 4.8 mg/dl. Group 2 individuals were predominantly male and had higher levels of blood pressure, increased body mass index, waist circumference, and a greater degree of insulin resistance. Additionally, greater lipid profile abnormalities were detected. This group also exhibited a significantly decreased fractional excretion of UA. Multivariate analysis demonstrated that serum UA levels were correlated with male sex, waist circumference, estimated glomerular filtration rate (eGFR), serum calcium and insulin levels, as well as with fractional excretion of UA. A positive association between serum UA levels and the number diagnostic criteria of the metabolic syndrome (MtS) was also noticed. After reclassification of subjects according to UA quartiles, individuals with UA levels ≥ 3.8 mg/dl had significantly higher odds (2.5-fold to 9.8-fold) of having MtS after adjustment of age, sex, and eGFR.

CONCLUSIONS

Uric acid levels in middle-aged, treatment-naïve hypertensive patients are correlated with risk factors for cardiovascular and renal disease.

Elevated uric acid is related to the no-/slow-reflow phenomenon in STEMI undergoing primary PCI

BACKGROUND

No-/slow-reflow phenomenon (NRP) is a severe complication in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). This study aimed to explore the relationship between elevated serum uric acid (SUA) and NRP in patients with STEMI undergoing pPCI, focusing on inflammation and angiographic findings.

METHODS

A total of 610 patients who received pPCI for STEMI were retrospectively enrolled. Patients were divided into a hyperuricaemia group and a non-hyperuricaemia group according to SUA levels. Clinical information and angiographic indicators were compared between the two groups. Thrombolysis in myocardial infarction (TIMI) flow and TIMI myocardial perfusion grade (TMPG) <3 after stent implantation were defined as TIMI-NRP and TMPG-NRP, respectively. A logistic model was used to analyse the relationship between hyperuricaemia and NRP.

RESULTS

The hyperuricaemia group had a higher incidence of TIMI-NRP (24.9% vs 14.0%, p < .001) and TMPG-NRP (33.0% vs 24.9%, p = .03), higher levels of C-reactive protein (7.2 vs 4.1 mg/L, p < .001) and worse left ventricular ejection fraction (51.5% vs 54.0%, p = .002) than the non-hyperuricaemia group. As for angiographic findings, there was no significant difference between the two groups in terms of lesion characteristics measured by quantitative coronary angiography. After multivariable adjustment, elevated SUA was significantly associated with TIMI-NRP (odds ratio: 1.94, 95% confidence interval: 1.24-3.01, p = .003). Subgroup analysis showed that the effect of hyperuricaemia in TIMI-NRP was more pronounced in patients with delayed perfusion as well as in patients with diabetes mellitus.

CONCLUSIONS

Elevated SUA is associated with severe inflammation and has higher incidence of TIMI-NRP in patients with STEMI undergoing pPCI, especially in those with delayed perfusion or diabetes mellitus.

Study on the levels of N-nitrosamine compounds and untargeted metabolomics in patients with colorectal cancer

Plasma samples were collected from 34 patients with advanced CRC and 92 healthy persons (control group), and the levels of 9 VNAs were measured using GC-MS. Untargeted metabolomics analysis was performed using LC-MS/MS. Partial least squares discriminant analysis (PLS-DA) and hierarchical cluster analysis were used to determine differential metabolites between the 2 groups. Receiver operating characteristic (ROC) curve analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed on the differential metabolites. It turned out that the detection rates of N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR) in patients with CRC were higher than in the control group (P < 0.05). N-nitrosomethylethylamine (NMEA) and N-nitrosodiphenylamine (NDPhA) were not detected in CRC patients. NDMA, N-nitrosodibutylamine (NDBA), N-nitrosopiperidine (NPIP), and NPYR were detected in male and female patients with CRC. There was no difference in VNAs exposure between the sexes of CRC patients. In the positive and negative ion mode, a total of 132 differential metabolites and 6 differential metabolic pathways were detected. Adenosine 5'-monophosphate, hypoxanthine, 11,12-epoxy-(5Z,8Z,11Z)-icosatrienoic acid, 16(R)-HETE, acetylcarnitine, and lysophosphatidic acid (LPA 20:5, LPA 20:4) were candidate biomarkers with higher predictive value. Hypoxanthine and xanthine metabolic pathways were associated with changes in VNAs in CRC patients. In summary, the effects of changes of VNAs in the plasma of CRC patients (especially NDMA and NPYR) on the progression of CRC should attract attention. Abnormalities of adenine and guanine and downstream hypoxanthine-xanthine metabolic pathways were closely related to changes of VNAs and metabolomics in CRC patients.

Alteration of Gut Microbiome and Correlated Amino Acid Metabolism Contribute to Hyperuricemia and Th17-Driven Inflammation in Uox-KO Mice

Although gut dysbiosis had been demonstrated to be an important factor affecting hyperuricemia (HUA) and gout, little is known for its potential mechanistic connections. In this study, Uox-KO mice model that with spontaneously developed pronounced HUA and urate nephropathy was used to explore the pathophysiologic mechanism of microbiota alterations in HUA and gout with integrated multi-omics analysis. 16S rRNA gene sequencing was performed to characterize the characteristic bacteria, and untargeted LC/MS analysis was applied to reveal the featured metabolites. Our results showed there was a significant shift in gut microbiota composition and function in Uox-KO mice compared to WT mice and apparent metabolomics differences between the two groups. Among them, amino acids metabolism appears to play a critical role. Correlation analysis further revealed that the characteristic metabolites were strongly influenced by the discrepant bacterial genera. Furthermore, impairment of intestinal integrity and profound alterations in the profile of solute carrier family resulted in dysregulation of amino acids transportation, which subsequently impacted serum uric acid level and CD4⁺ Th17 driven inflammation. Together, these data indicate that gut dysbiosis promotes purine metabolism disorder and inflammation in Uox-KO mice. Remodeling the gut microbiota is a promising strategy to combat HUA and gout.

Prognostic value of hyperuricemia for patients with sepsis in the intensive care unit

This study evaluated the relationship between hyperuricemia at admission and the clinical prognosis of patients with sepsis. The data were obtained from the Intensive Care Medical Information Database III. The patients were divided into a normal serum uric acid group and a hyperuricemia group. The main outcome was 90-day mortality, and the secondary outcomes were hospital mortality, 30-day mortality, and acute kidney injury. Propensity score matching was used to balance the baseline characteristics of the groups. Our study retrospectively included 954 patients. Before and after propensity score matching, the incidence of AKI, the 30-day and 90-day mortality rates were significantly higher in the hyperuricemia group. Cox regression analysis showed that hyperuricemia was significantly associated with 90-day mortality (HR 1.648, 95% CI 1.215–2.234, p = 0.006), and hyperuricemia was significantly associated with the incidence of AKI (HR 1.773, 95% CI 1.107–2.841, p = 0.017). The Kaplan–Meier survival curve showed that the 90-day survival rate was significantly lower in the hyperuricemia group. In patients with sepsis in the intensive care unit, hyperuricemia was significantly associated with increased risk 90-day all-cause mortality and the incidence of AKI.