Sleeve gastrectomy ameliorates renal injury in obesity-combined hyperuricemic nephropathy mice by modulating the AMPK/Nrf2/ABCG2 pathway.

Hyperuricemic nephropathy (HN) is renal injury caused by hyperuricemia (HUA). While sleeve gastrectomy (SG) has shown promise in improving renal injury in patients with obesity-related HN, the mechanisms are not fully understood. This study induced an obesity-combined HN model in male ob/ob mice and measured serum uric acid (SUA), creatinine, and other biochemical indicators 6 weeks post-surgery. Renal histological changes were evaluated through staining techniques, and the study also assessed renal adenosine monophosphate-activated protein kinase (AMPK) and nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation levels and urate transporter ABCG2 expression. In vitro experiments involved Nrf2 knockdown in AMPK-activated HK-2 cells and ChIP to confirm Nrf2 binding to the ABCG2 promoter. Results showed that SG reduced SUA levels, serum creatinine, and blood urea nitrogen, increased p-AMPK, p-Nrf2 protein, and ABCG2 expression, and alleviated renal fibrosis and inflammation. In vitro, Nrf2 knockdown down-regulated ABCG2 expression, and ChIP confirmed Nrf2's role in ABCG2 transcription. The study suggests that SG may improve renal injury in HN mice by modulating the AMPK/Nrf2 pathway and upregulating ABCG2 transcription.

Empowering probiotics with high xanthine transport for effective hyperuricemia management.

Hyperuricemia, a prevalent metabolic disorder, poses a susceptibility to various complications. The conventional pharmacotherapeutic approaches for hyperuricemia often entail notable adverse effects, posing substantial clinical challenges. Hence, the imperative lies in the development of novel, safe and effective strategies for preventing and treating hyperuricemia. Here, we developed a probiotic Escherichia coli Nissle 1917 strain, designated as YES301, which contains a rationally designed xanthine importer XanQ, enabling efficient uptake of xanthine and hypoxanthine, consequently leading to reduced serum uric acid concentrations and amelioration of renal impairments in a murine model of hyperuricemia. Importantly, YES301 exhibited a therapeutic efficacy comparable to allopurinol, a conventional uric acid-lowering agent, and manifesting fewer adverse effects and enhanced biosafety. These findings highlight the promising potential of engineered probiotics in the management of hyperuricemia through reducing intestinal purine levels.

Harnessing Protein Hydrolysates and Peptides for Hyperuricemia Management: Insights into Sources, Mechanisms, Techniques, and Future Directions.

Hyperuricemia (HUA) is a metabolic disorder characterized by an imbalance in uric acid production and excretion, frequently leading to gout and various chronic conditions. Novel bioactive compounds offer effective alternatives for managing HUA, reducing side effects of traditional medications. Recent studies have highlighted the therapeutic potential of protein hydrolysates and peptides in managing HUA. This review focuses on preparing and applying protein hydrolysates to treat HUA and explores peptides for xanthine oxidase inhibition. Particularly, we discuss their origins, enzymatic approaches, and mechanisms of action in detail. The review provides an updated understanding of HUA pathogenesis, current pharmacological interventions, and methodologies for the preparation, purification, identification, and assessment of these compounds. Furthermore, to explore the application of protein hydrolysates and peptides in the food industry, we also address challenges and propose solutions related to the safety, bitterness, oral delivery, and the integration of artificial intelligence in peptide discovery. Bridging traditional pharmacological approaches and innovative dietary interventions, this study paves the way for future research and development in HUA management, contributing to the utilization of proteins from different food sources. In conclusion, protein hydrolysates and peptides show significant promise as safe agents and dietary interventions for preventing and treating HUA.

A metabolomics perspective reveals the mechanism of the uric acid-lowering effect of Prunus salicina Lindl. cv. "furong" polyphenols in hypoxanthine and potassium oxybate-induced hyperuricemic mice.

The incidence of hyperuricemia (HUA) shows a gradually increasing trend towards affecting younger individuals, and it can significantly harm the overall health status of the body. Based on a metabolomics perspective, this study reveals the mechanism of the uric acid-lowering action of Prunus salicina Lindl. cv. "furong" polyphenols (PSLP) on a hyperuricemia mouse model induced by hypoxanthine and potassium oxybutyrate. The results demonstrate that PSLP comprise an effective treatment strategy for reducing the levels of serum uric acid (SUA), serum creatinine (SCr) and blood urea nitrogen (BUN) in HUA mice (p < 0.05), wherein the maximum decrease rates are up to 44.50%, 29.46%, and 32.95%, respectively. PSLP are observed to exert a pronounced inhibitory effect on the activities of xanthine oxidase (XOD) and adenosine deaminase (ADA) in the livers of HUA mice, with reductions of up to 16.36% and 20.13%, respectively. These findings illustrate that PSLP exert a significant uric acid-lowering effect. Subsequent metabolomic analysis of mouse serum identified 28 potential biomarkers for hyperuricemia, whose levels were markedly diminished by PSLP. This process involved alterations in purine, glycine, the pentose phosphate pathway, and galactose metabolism. Twenty-eight potential biomarkers were identified for hyperuricemia by subsequent metabolomic analysis of mouse serum, whose levels were markedly reversed by PSLP intervention. The regulation of HUA by PSLP involved alterations in purine metabolism, glycerolipid metabolism, the pentose phosphate pathway, and galactose metabolism. The mechanism of PSLP ameliorated hyperuricemia might be attributed to reduction of the level of the uric acid precursor ribose-5-phosphate in the pentose phosphate pathway, the inhibition of the activities of uric acid synthase XOD and ADA in purine metabolism, and reduction of the synthesis of the end product uric acid. This study provides a theoretical basis for the development of functional foods based on PSLP, which can potentially reduce uric acid levels.

LincRNA-p21/AIF-1/CMPK2/NLRP3 pathway promoted inflammation, autophagy and apoptosis of human tubular epithelial cell induced by urate via exosomes.

Urate nephropathy, a common complication of hyperuricemia, has garnered increasing attention worldwide. However, the exact pathogenesis of this condition remains unclear. Currently, inflammation is widely accepted as the key factor in urate nephropathy. Therefore, the aim of this study was to elucidate the interaction of lincRNA-p21/AIF-1/CMPK2/NLRP3 via exosomes in urate nephropathy. This study evaluated the effect of lincRNA-p21/AIF-1/CMPK2/NLRP3 using clinical data collected from patients with urate nephropathy and human renal tubular epithelial cells (HK2) cultured with different concentrations of urate. In clinical research section, the level of lincRNA-p21/AIF-1 in exosomes of urine in patients with hyperuricemia or urate nephropathy was found to be increased, particularly in patients with urate nephropathy. In vitro study section, the level of exosomes, inflammation, autophagy, and apoptosis was increased in HK2 cells induced by urate. Additionally, the expression of lincRNA-p21, AIF-1, CMPK2, and NLRP3 was upregulated in exosomes and HK2 cells. Furthermore, manipulating the activity of lincRNA-p21, AIF-1, CMPK2, and NLRP3 through overexpression or interference vectors regulated the level of inflammation, autophagy, and apoptosis in HK2 cells. In conclusion, the pathway of lincRNA-p21/AIF-1/CMPK2/NLRP3 contributed to inflammation, autophagy, and apoptosis of human renal tubular epithelial cell induced by urate via exosomes. Additionally, the specific exosomes in urine might serve as novel biomarkers for urate nephropathy.

Alterations in the gut microbiome and metabolism profiles reveal the possible molecular mechanism of renal injury induced by hyperuricemia in a mouse model of renal insufficiency.

Objectives: To investigate the role of the intestinal flora and metabolites in the development of hyperuricemic renal injury in chronic kidney disease (CKD).Methods: Unilaterally nephrectomized mice were fed with adenine and potassium oxonate for 9 weeks. HE staining combined with plasma biochemical indicators was used to evaluate renal pathological and functional changes. We conducted 16S rRNA sequencing and untargeted metabolomics on feces and plasma samples to reveale changes in intestinal microbiota and metabolites.Result: Our analysis revealed significant differences in 15 bacterial genera, with 7 being upregulated and 8 being downregulated. Furthermore, metabolomic analysis revealed changes in the distribution of amino acid and biotin metabolites in basic metabolic pathways in both feces and serum. Specifically, differentially abundant metabolites in feces were associated primarily with histidine metabolism; the biosynthesis of phenylalanine, tyrosine, and tryptophan; and tyrosine metabolism. In plasma, the differentially abundant metabolites were involved in multiple metabolic pathways, including aminoacyl-tRNA biosynthesis; glycine, serine, and threonine amino acid metabolism; valine, leucine, and isoleucine biosynthesis; tyrosine biosynthesis and metabolism; biotin metabolism; and taurine and hypotaurine metabolism. Furthermore, correlation analysis revealed that Akkermansia, UCG-005, Lachnospiraceae_NK4A136_group, Lactococcus, and Butymonas were associated with various differentially abundant metabolites as well as renal function, oxidative stress, and mitophagy. The changes in the intestinal flora observed in hyperuricemia may lead to imbalances in amino acid and biotin metabolism in both the intestine and host, ultimately affecting oxidative stress and mitophagy in mice and accelerating the progression of CKD.Conclusion: Our findings provide insights into a potential pathogenic mechanism by which hyperuricemia exacerbates renal injury in mice with renal insufficiency. Understanding these pathways may offer new therapeutic strategies for managing hyperuricemic renal injury in CKD patients.

Plantaginis Semen Ameliorates Hyperuricemia Induced by Potassium Oxonate.

Plantaginis semen is the dried ripe seed of Plantago asiatica L. or Plantago depressa Willd., which has a long history in alleviating hyperuricemia (HUA) and chronic kidney diseases. While the major chemical ingredients and mechanism remained to be illustrated. Therefore, this work aimed to elucidate the chemicals and working mechanisms of PS for HUA. UPLC-QE-Orbitrap-MS was applied to identify the main components of PS in vitro and in vivo. RNA sequencing (RNA-seq) was conducted to explore the gene expression profile, and the genes involved were further confirmed by real-time quantitative PCR (RT-qPCR). A total of 39 components were identified from PS, and 13 of them were detected in the rat serum after treating the rat with PS. The kidney tissue injury and serum uric acid (UA), xanthine oxidase (XOD), and cytokine levels were reversed by PS. Meanwhile, renal urate anion transporter 1 (Urat1) and glucose transporter 9 (Glut9) levels were reversed with PS treatment. RNA-seq analysis showed that the PPAR signaling pathway; glycine, serine, and threonine metabolism signaling pathway; and fatty acid metabolism signaling pathway were significantly modified by PS treatment. Further, the gene expression of Slc7a8, Pck1, Mgll, and Bhmt were significantly elevated, and Fkbp5 was downregulated, consistent with RNA-seq results. The PPAR signaling pathway involved Pparα, Pparγ, Lpl, Plin5, Atgl, and Hsl were elevated by PS treatment. URAT1 and PPARα proteins levels were confirmed by Western blotting. In conclusion, this study elucidates the chemical profile and working mechanisms of PS for prevention and therapy of HUA and provides a promising traditional Chinese medicine agency for HUA prophylaxis.

Lipidomics and metabolomics investigation into the effect of DAG dietary intervention on hyperuricemia in athletes.

The occurrence of hyperuricemia (HUA; elevated serum uric acid) in athletes is relatively high despite that exercise can potentially reduce the risk of developing this condition. Although recent studies have shown the beneficial properties of DAG in improving overall metabolic profiles, a comprehensive understanding of the effect of DAG in modulating HUA in athletes is still lacking. In this study, we leveraged combinatorial lipidomics and metabolomics to investigate the effect of replacing TAG with DAG in the diet of athletes with HUA. A total of 1,074 lipids and metabolites from 94 classes were quantitated in serum from 33 athletes, who were categorized into responders and non-responders based on whether serum uric acid levels returned to healthy levels after the DAG diet intervention. Lipidomics and metabolomics analyses revealed lower levels of xanthine and uric acid in responders, accompanied by elevated plasmalogen phosphatidylcholines and diminished acylcarnitine levels. Our results highlighted the mechanisms behind how the DAG diet circumvented the risk and effects associated with high uric acid via lowered triglycerides at baseline influencing the absorption of DAG resulting in a decline in ROS and uric acid production, increased phospholipid levels associated with reduced p-Cresol metabolism potentially impacting on intestinal excretion of uric acid as well as improved ammonia recycling contributing to decreased serum uric acid levels in responders. These observed alterations might be suggestive that successful implementation of the DAG diet can potentially minimize the likelihood of a potentially vicious cycle occurring in high uric acid, elevated ROS, and impaired mitochondrial metabolism environment.

[Modern understanding of uric acid metabolism disorders and progress in traditional Chinese medicine prevention and treatment].

The abnormal production and/or excretion of uric acid can lead to a disorder in uric acid metabolism, resulting in hyperuricemia, uric acid nephropathy, gouty arthritis, and other diseases related to uric acid metabolism disorder. The clinical incidence of these diseases is increasing year after year, posing a significant threat to public health. In the past, hyperuricemia and gouty arthritis were often considered different diseases, with uric acid nephropathy being a complication of hyperuricemia. However, recent research has challenged this perspective, suggesting that hyperuricemia, uric acid nephropathy, and gouty arthritis are different stages of the same disease, with urate deposition as the common pathological feature. This article offered a comprehensive overview of the current understanding of hyperuricemia, uric acid nephropathy, and gouty arthritis in both traditional Chinese medicine(TCM) and western medicine. It delved into the most up-to-date insights into the involvement of urate deposition in the pathogenesis of uric acid metabolism disorders and highlighted the dominant role of TCM in the prevention and treatment of uric acid metabolism disorders, so as to provide a reference for effective intervention strategies and drug development in uric acid metabolism disorder-related diseases.

The Role of Hyperuricemia in Cardiac Diseases: Evidence, Controversies, and Therapeutic Strategies.

Hyperuricemia (HUA) may lead to myocardial cell damage, thereby promoting the occurrence and adverse outcomes of heart diseases. In this review, we discuss the latest clinical research progress, and explore the impact of HUA on myocardial damage-related diseases such as myocardial infarction, arrhythmias, and heart failure. We also combined recent findings from basic research to analyze potential mechanisms linking HUA with myocardial injury. In different pathological models (such as direct action of high uric acid on myocardial cells or combined with myocardial ischemia-reperfusion model), HUA may cause damage by activating the NOD-like receptor protein 3 inflammasome-induced inflammatory response, interfering with cardiac cell energy metabolism, affecting antioxidant defense systems, and stimulating reactive oxygen species production to enhance the oxidative stress response, ultimately resulting in decreased cardiac function. Additionally, we discuss the impact of lowering uric acid intervention therapy and potential safety issues that may arise. However, as the mechanism underlying HUA-induced myocardial injury is poorly defined, further research is warranted to aid in the development novel therapeutic strategies for HUA-related cardiovascular diseases.

Biotransformation characteristics of urate-lowering probiotic fermented apple juice and potential regulatory mechanisms for ameliorating hyperuricemia via mediating gut microbiota and metabolic pathways.

Hyperuricemia has evolved into a global public health concern, and applying probiotics fermented apple juice holds promise for alleviating this condition. This study aimed to investigate the biotransformation and metabolic features of urate-lowering probiotics sequentially fermented dealcoholized apple juice (PSFA), and assess its ameliorative effects and potential mechanisms on hyperuricemia mice. Results showed that CICC 6074 and 20,292 possessed excellent purine, nucleotide and nucleoside degradation and acid and bile salt resistance; sequential fermentation decreased the fructose in apple juice, and viable counts reached 3.76 × 108 CFU/mL. Histopathological analysis showed that PSFA ameliorated kidney damage in hyperuricemia mice. Furthermore, PSFA significantly reduced Urea, Creatinine and Uric acid levels in hyperuricemia mice; and inhibited xanthine oxidase activity and the expression of pro-inflammatory factors. Importantly, PSFA reversed gut microbiota dysbiosis and raised the abundance of beneficial bacteria (Lactobacillush, Faecalibaculum and Lachnospiraceae_NK4A136_group). KEGG and COG functional prediction results revealed that the potential mechanism of PSFA to ameliorate hyperuricemia may be lipid metabolism and glycolysis pathways.

Atavistic strategy for the treatment of hyperuricemia via ionizable liposomal mRNA.

Hyperuricemia is associated with an increased risk of gout, hypertension, diabetes, and cardiovascular diseases. Most mammals maintain normal serum uric acid (SUA) via urate oxidase (Uox), an enzyme that metabolizes poorly-soluble UA to highly-soluble allantoin. In contrast, Uox became a pseudogene in humans and apes over the long course of evolution. Here we demonstrate an atavistic strategy for treating hyperuricemia based on endogenous expression of Uox in hepatocytes mediated by mRNA (mUox) loaded with an ionizable lipid nanoparticle termed iLAND. mUox@iLAND allows effective transfection and protein expression in vitro. A single dose of mUox@iLAND lowers SUA levels for several weeks in two female murine models, including a novel long-lasting model, which is also confirmed by metabolomics analysis. Together with the excellent safety profiles observed in vivo, the proposed mRNA agent demonstrates substantial potential for hyperuricemia therapy and the prevention of associated conditions.

Anti-hyperuricemia effect of Clerodendranthus spicatus: a molecular biology study combined with metabolomics.

Hyperuricemia (HUA), a metabolic disease caused by excessive production or decreased excretion of uric acid (UA), has been reported to be closely associated with a variety of UA transporters. Clerodendranthus spicatus (C. spicatus) is an herbal widely used in China for the treatment of HUA. However, the mechanism has not been clarified. Here, the rat model of HUA was induced via 10% fructose. The levels of biochemical indicators, including UA, xanthine oxidase (XOD), adenosine deaminase (ADA), blood urea nitrogen (BUN), and creatinine (Cre), were measured. Western blotting was applied to explore its effect on renal UA transporters, such as urate transporter1 (URAT1), glucose transporter 9 (GLUT9), and ATP-binding cassette super-family G member 2 (ABCG2). Furthermore, the effect of C. spicatus on plasma metabolites was identified by metabolomics. Our results showed that C. spicatus could significantly reduce the serum levels of UA, XOD, ADA and Cre, and improve the renal pathological changes in HUA rats. Meanwhile, C. spicatus significantly inhibited the expression of URAT1 and GLUT9, while increased the expression of ABCG2 in a dose-dependent manner. Metabolomics showed that 13 components, including 1-Palmitoyl-2-Arachidonoyl-sn-glycero-3-PE, Tyr-Leu and N-cis-15-Tetracosenoyl-C18-sphingosine, were identified as potential biomarkers for the UA-lowering effect of C. spicatus. In addition, pathway enrichment analysis revealed that arginine biosynthesis, biosynthesis of amino acids, pyrimidine metabolism and other metabolic pathways might be involved in the protection of C. spicatus against HUA. This study is the first to explore the mechanism of anti-HUA of C. spicatus through molecular biology and metabolomics analysis, which provides new ideas for the treatment of HUA.

Intermittent high altitude hypoxia induced liver and kidney injury leading to hyperuricemia.

About 140 million people worldwide live at an altitude above 2500 m. Studies have showed an increase of the incidence of hyperuricemia among plateau populations, but little is known about the possible mechanisms. This study aims to assess the effects of high altitude on hyperuricemia and explore the corresponding mechanisms at the histological, inflammatory and molecular levels. This study finds that intermittent hypobaric hypoxia (IHH) exposure results in an increase of serum uric acid level and a decrease of uric acid clearance rate. Compared with the control group, the IHH group shows significant increases in hemoglobin concentration (HGB) and red blood cell counts (RBC), indicating that high altitude hyperuricemia is associated with polycythemia. This study also shows that IHH exposure induces oxidative stress, which causes the injury of liver and renal structures and functions. Additionally, altered expressions of organic anion transporter 1 (OAT1) and organic cation transporter 1 (OCT1) of kidney have been detected in the IHH exposed rats. The adenosine deaminase (ADA) expression levels and the xanthione oxidase (XOD) and ADA activity of liver of the IHH exposure group have significantly increased compared with those of the control group. Furthermore, the spleen coefficients, IL-2, IL-1ß and IL-8, have seen significant increases among the IHH exposure group. TLR/MyD88/NF-κB pathway is activated in the process of IHH induced inflammatory response in joints. Importantly, these results jointly show that IHH exposure causes hyperuricemia. IHH induced oxidative stress along with liver and kidney injury, unusual expression of the uric acid synthesis/excretion regulator and inflammatory response, thus suggesting a potential mechanism underlying IHH-induced hyperuricemia.

Structural basis for urate recognition and apigenin inhibition of human GLUT9.

Urate, the physiological form of uric acid and a potent antioxidant in serum, plays a pivotal role in scavenging reactive oxygen species. Yet excessive accumulation of urate, known as hyperuricemia, is the primary risk factor for the development of gout. The high-capacity urate transporter GLUT9 represents a promising target for gout treatment. Here, we present cryo-electron microscopy structures of human GLUT9 in complex with urate or its inhibitor apigenin at overall resolutions of 3.5 Å and 3.3 Å, respectively. In both structures, GLUT9 exhibits an inward open conformation, wherein the substrate binding pocket faces the intracellular side. These structures unveil the molecular basis for GLUT9's substrate preference of urate over glucose, and show that apigenin acts as a competitive inhibitor by occupying the substrate binding site. Our findings provide critical information for the development of specific inhibitors targeting GLUT9 as potential therapeutics for gout and hyperuricemia.

WWC1 upregulation accelerates hyperuricemia by reduction in renal uric acid excretion through Hippo signaling pathway.

Hyperuricemia (HUA) is a metabolic disorder characterized by elevated serum uric acid (UA), primarily attributed to the hepatic overproduction and renal underexcretion of UA. Despite the elucidation of molecular pathways associated with this underexcretion, the etiology of HUA remains largely unknown. In our study, using by Uox knockout rats, HUA mouse, and cell line models, we discovered that the increased WWC1 levels were associated with decreased renal UA excretion. Additionally, using knockdown and overexpression approaches, we found that WWC1 inhibited UA excretion in renal tubular epithelial cells. Mechanistically, WWC1 activated the Hippo pathway, leading to phosphorylation and subsequent degradation of the downstream transcription factor YAP1, thereby impairing the ABCG2 and OAT3 expression through transcriptional regulation. Consequently, this reduction led to a decrease in UA excretion in renal tubular epithelial cells. In conclusion, our study has elucidated the role of upregulated WWC1 in renal tubular epithelial cells inhibiting the excretion of UA in the kidneys and causing HUA.

[Uric Acid Metabolism, Uric Acid Transporters and Dysuricemia].

Serum urate levels are determined by the balance between uric acid production and uric acid excretion capacity from the kidneys and intestinal tract. Dysuricemia, including hyperuricemia and hypouricemia, develops when the balance shifts towards an increase or a decrease in the uric acid pool. Hyperuricemia is mostly a multifactorial genetic disorder involving several disease susceptibility genes and environmental factors. Hypouricemia, on the other hand, is caused by genetic abnormalities. The main genes involved in dysuricemia are xanthine oxidoreductase, an enzyme that produces uric acid, and the urate transporters urate transporter 1/solute carrier family 22 member 12 (URAT1/SLC22A12), glucose transporter 9/solute carrier family 2 member 9 (GLUT9/SLC2A9) and ATP binding cassette subfamily G member 2 (ABCG2). Deficiency of xanthine oxidoreductase results in xanthinuria, a rare disease with marked hypouricemia. Xanthinuria can be due to a single deficiency of xanthine oxidoreductase or in combination with aldehyde oxidase deficiency as well. The latter is caused by a deficiency in molybdenum cofactor sulfurase, which is responsible for adding sulphur atoms to the molybdenum cofactor required for xanthine oxidoreductase and aldehyde oxidase to exert their action. URAT1/SLC22A12 and GLUT9/SLC2A9 are involved in urate reabsorption and their deficiency leads to renal hypouricemia, a condition that is common in Japanese due to URAT1/SLC22A12 deficiency. On the other hand, ABCG2 is involved in the secretion of urate, and many Japanese have single nucleotide polymorphisms that result in its reduced function, leading to hyperuricemia. In particular, severe dysfunction of ABCG2 leads to hyperuricemia with reduced extrarenal excretion.

Identification of Hyperuricemia Alleviating Peptides from Yellow Tuna Thunnus albacares.

The development of food-derived antihyperuricemic substances is important for alleviating hyperuricemia (HUA) and associated inflammation. Here, novel peptides fromThunnus albacares (TAP) with strong antihyperuricemic activity were prepared. TAP was prepared by alkaline protease (molecular weight <1000 Da), with an IC50 value of xanthine oxidase inhibitory activity of 2.498 mg/mL, and 5 mg/mL TAP could reduce uric acid (UA) by 33.62% in human kidney-2 (HK-2) cells (P < 0.01). Mice were fed a high-purine diet and injected with potassium oxonate to induce HUA. Oral administration of TAP (600 mg/kg/d) reduced serum UA significantly by 42.22% and increased urine UA by 79.02% (P < 0.01) via regulating urate transporters GLUT9, organic anion transporter 1, and ATP-binding cassette subfamily G2. Meantime, TAP exhibited hepatoprotective and nephroprotective effects, according to histological analysis. Besides, HUA mice treated with TAP showed anti-inflammatory activity by decreasing the levels of toll-like receptor 4, nuclear factors-κB p65, NLRP3, ASC, and Caspase-1 in the kidneys (P < 0.01). According to serum non-targeted metabolomics, 91 differential metabolites between the MC and TAP groups were identified, and purine metabolism was considered to be the main pathway for TAP alleviating HUA. In a word, TAP exhibited strong antihyperuricemic activity both in vitro and in vivo.

Current updates for hyperuricemia and gout in age-related macular degeneration.

The escalating prevalence of metabolic syndrome poses a significant public health challenge, particularly among aging populations, with metabolic dysfunctions contributing to pro-inflammatory states. In this review, we delved into the less recognized association between hyperuricemia (HUA), a manifestation of metabolic syndrome and a primary risk factor for gout, and age-related macular degeneration (AMD), a sight-threatening ailment predominantly affecting the elderly. In recent years, inflammation, particularly its involvement in complement pathway dysregulation, has gained prominence in AMD pathophysiology. The contradictory role of uric acid (UA) in intercellular and intracellular environments was discussed, highlighting its antioxidant properties in plasma and its pro-oxidant effects intracellularly. Emerging evidence suggests a potential link between elevated serum uric acid levels and choroid neovascularization in AMD, providing insights into the role of HUA in retinal pathologies. Various pathways, including crystal-induced and non-crystal-induced mechanisms, were proposed to indicate the need for further research into the precise molecular interactions. The implication of HUA in AMD underscores its potential involvement in retinal pathologies, which entails interdisciplinary collaboration for a comprehensive understanding of its impact on retina and related clinical manifestations.