Acute kidney injury associated with febuxostat and allopurinol: a post-marketing study

Kidney targeting and modulating macrophage polarization through AMPK signaling: Therapeutic mechanism of berberine in uric acid nephropathy

Uric acid nephropathy (UAN), caused by a common metabolic disorder resulting from hyperuricemia (HUA), has an increasing incidence. Previous studies have shown that berberine (BBR) has clear urate-lowering and anti-inflammatory effects in UAN mice, but its mechanism needs to be further clarified. Therefore, Potassium Oxonate (PO) combined with hypoxanthine (HX) induced UAN mice model and MSU induced THP-1 cells polarization model were adopted to investigate the mechanism of BBR on UAN in terms of tissue distribution and molecular pharmacology. Study unveiled that BBR was first found to bind to red blood cells (RBCs), which were recognized and phagocytosed by monocytes, then recruited by the injured kidney. Subsequently, BBR was enriched and functional in damaged kidney. The results of in vivo experiments revealed that, BBR reduced UA, BUN, CRE levels as well as the release of TNF-α, IL-1β, IL-18 and IL-6, and alleviated renal injury in UAN mice, as consistent with previous studies. Additionally, BBR decreased MCP-1 expression, while diminishing macrophage infiltration and decreasing M1 proportion as determined by RT-qPCR. In vitro experiments, demonstrated that MSU promoted inflammatory polarization of THP-1 cells, while BBR reduced synthesis of inflammatory factors and inhibited MSU-induced inflammatory polarization. These effects of BBR were dependent on AMPK activation along with indirect inhibition of NF-κB signaling pathway mediated. However, the anti-inflammatory and macrophage polarization regulation effects of BBR were completely reversed upon administration of Compound C, an AMPK inhibitor. Therefore, BBR ameliorated kidney injury via regulating macrophage polarization through AMPK, which has therapeutic potential for UAN patients.

A potential therapeutic agent for the treatment of hyperuricemia and gout: 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide

Uric acid, the metabolic product of purines, relies on xanthine oxidase (XOD) for production. XOD is a target for the development of drugs for hyperuricemia (HUA) and gout. Currently, treatment options remain limited for gout patients. 3, 4-Dihydroxy-5-nitrobenzaldehyde (DHNB) is a derivative of the natural product protocatechualdehyde with good biological activity. In this work, we identify a DHNB thiosemicarbazide class of compounds that targets XOD. 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazone can effectively inhibit XOD activity (IC50 value: 0.0437 μM) and exhibits a mixed inhibitory effect. In a mouse model of acute hyperuricemia, a moderate dose (10 mg/kg.w) of 3,4-dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide effectively controlled the serum uric acid content and significantly inhibited serum XOD activity. In addition, 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide showed favorable safety profiles, and mice treated with the target compound did not show any symptoms of general toxicity following a single dose of 500 mg/kg. In the allopurinol group, 50 % of the mice died. These results provide a structural framework and mechanism of XOD inhibition that may facilitate the design of hyperuricemia and gout treatments.

Role of CD44 expressed in renal tubules during maladaptive repair in renal fibrogenesis in an allopurinol-induced rat model of chronic kidney disease

The kidney is a major target organ for the adverse effects of pharmaceuticals; renal tubular epithelial cells (TECs) are particularly vulnerable to drug-induced toxicity. TECs have regenerative capacity; however, maladaptive repair of TECs after injury leads to renal fibrosis, resulting in chronic kidney disease (CKD). We previously reported the specific expression of CD44 in failed-repair TECs of rat CKD model induced by ischemia reperfusion injury. Here, we investigated the pathophysiological role of CD44 in renal fibrogenesis in allopurinol-treated rat CKD model. Dilated or atrophic TECs expressing CD44 in fibrotic areas were collected by laser microdissection and subjected to microarray analysis. Gene ontology showed that extracellular matrix (ECM)-related genes were upregulated and differentiation-related genes were downregulated in dilated/atrophic TECs. Ingenuity Pathway Analysis identified CD44 as an upstream regulator of fibrosis-related genes, including Fn1, which encodes fibronectin. Immunohistochemistry demonstrated that dilated/atrophic TECs expressing CD44 showed decreases in differentiation markers of TECs and clear expression of mesenchymal markers during basement membrane attachment. In situ hybridization revealed an increase in Fn1 mRNA in the cytoplasm of dilated/atrophic TECs, whereas fibronectin was localized in the stroma around these TECs, supporting the production/secretion of ECM by dilated/atrophic TECs. Overall, these data indicated that dilated/atrophic TECs underwent a partial epithelial-mesenchymal transition (pEMT) and that CD44 promoted renal fibrogenesis via induction of ECM production in failed-repair TECs exhibiting pEMT. CD44 was detected in the urine and serum of APL-treated rats, which may reflect the expression of CD44 in the kidney.

Exploring the inhibition mechanism of interleukin-1-beta in gouty arthritis by polygonum cuspidatum using network pharmacology and molecular docking: A review

Polygonum cuspidatum (Huzhang, HZ) is one of the commonly used traditional Chinese medicines for treating gouty arthritis (GA), but the specific mechanism is not clear. This study employed network pharmacology and molecular docking techniques to examine the molecular mechanisms underlying the therapeutic effects of HZ on GA. The network pharmacology approach, including active ingredient and target screening, drug-compound-target-disease network construction, protein-protein interaction (PPI) networks, enrichment analysis, and molecular docking, was used to explore the mechanism of HZ against GA. Ten active ingredients of HZ were predicted to interact with 191 targets, 14 of which interact with GA targets. Network pharmacology showed that quercetin, physovenine, luteolin, and beta-sitosterol are the core components of HZ, and IL (interleukin)-1β, IL-6, and tumor necrosis factor (TNF) are the core therapeutic targets. The mechanism of HZ in GA treatment was shown to be related to the IL-17 signaling pathway, NOD-like receptor signaling pathway, and Toll-like receptor signaling pathway, and is involved in the inflammatory response, positive regulation of gene expression, cellular response to lipopolysaccharide, and other biological processes. Molecular docking showed that all four core compounds had good binding properties to IL-1β, with luteolin and beta-sitosterol showing better docking results than anakinra, suggesting that they could be used as natural IL-1β inhibitors in further experimental studies. The mechanism of action of HZ against GA has multi-target and multi-pathway characteristics, which provides an important theoretical basis for the study of the active ingredients of HZ as natural IL-1β inhibitors.

A feasible HPTLC method for concurrent quantitation of allopurinol-montelukast co-therapy in plasma and evaluation of their hepatic and renal effects in rats: Analytical, biochemical, and histopathological study

Recent studies presented the crucial role of montelukast (MON, a leukotriene receptor antagonist) against gouty arthritis and its protective effect on drug-induced liver and kidney injury. Allopurinol (ALO, a selective xanthine oxidase inhibitor) is also used for treatment of hyperuricemia, however, it induces hepatotoxicity and acute kidney injury. Therefore, this study introduces the first analytical/biochemical/histopathological assay for MON-ALO co-therapy and aims to: inspect the hepatic and renal impacts of ALO, MON and their combination in rats via biochemical and histopathological examinations, propose and validate a facile HPTLC method for concurrent estimation of ALO-MON binary mixture in human plasma, and employ this method to attain the targeted drugs in real rat plasma. First, the cited drugs in human plasma were simultaneously separated utilizing silica gel G 60 F₂₅₄-TLC plates. The separated bands were scanned at 268 nm demonstrating appropriate linearities (50.0-2000.0 ng band^-1 for each drug) and correlations (0.9986 and 0.9992 for ALO and MON, correspondingly). The calculated detection and quantitation limits, as well as recoveries confirmed the method's reliability. This procedure was validated, and the stability studies were achieved according to Bioanalytical Method Validation Guideline. This work was extended to investigate the possible hepatic and renal effects of ALO, MON and their co-therapy in rats. Using rat's gastric tube, the following was administered to four groups of male Wistar rats: Group Ia and Ib as control (received either saline or DMSO), Groups II, III, and IV were given MON, ALO, and MON+ALO, respectively. Good correlation between the measured biochemical parameters and the observed histopathological changes was encountered. Considerable drop in aspartate transaminase and alanine transaminase levels, in addition to lower liver damage changes were observed in the combination group compared to MON or ALO-treated groups. Regarding renal changes, ALO-MON co-therapy caused elevation in the serum creatinine and blood urea nitrogen levels when compared to controls and MON- or ALO-treated groups. Severe proteinaceous casts accumulation in kidney tubular lumen, severe congestion, and severe tubular necrosis were also noticed in the combination group. Lastly, this study suggests ALO-MON co-treatment not only as a preventive therapy against gouty arthritis but also as a new line to minimize ALO-induced hepatic injury. However, co-administration of ALO and MON should be further studied to assess the benefits and risks in various tissues, adjust the MON dosing, and monitor its nephrotoxic effect.

Ameliorative effect of cheqianzi decoction on hyperuricemia and kidney injury and underlying mechanism in rats

Cheqianzi Decoction (CQD) is a Traditional Chinese Medicine (TCM) formula comprising four herbs and is recorded in the Ancient Materia Medica "Shengji Zonglu". Individually, these four herbs have been shown to reduce uric acid (UA) levels, to treat hyperuricemia (HUA), and alleviate kidney damage. However, the therapeutic efficacy of the CQD and related mechanism are not yet clear. In this study, high performance liquid chromatography (HPLC) analysis confirmed that the contents of the chemical components of the four herbal medicines were in accordance with the provisions of the Chinese Pharmacopoeia. A total of 99 potential targets were identified in the network pharmacology analysis of CQD, indicating its involvement in the regulation of inflammatory and apoptotic signaling pathways, and potential value for treating HUA and alleviating kidney injury. In vivo pharmacodynamic studies showed that compared with the Model group, significantly decreased levels of serum uric acid (SUA), serum creatinine (SCr), blood urea nitrogen (BUN) (all P < 0.05), and inflammatory factors (P < 0.01) were detected in the CQD group. Quantitative real-time PCR and Western blot analyses showed that compared with the Model group, adenosine triphosphate (ATP)-binding cassette efflux transporter G2 (ABCG2) expression in the CQD group was significantly upregulated (P < 0.01) at both the mRNA and protein levels, while mRNA expression of Caspase3 and NOD-like receptor family member 3 (NLRP3) (P < 0.05) and protein expression of NLRP3 (P < 0.01) were significantly downregulated. In conclusion, CQD promotes UA excretion by activating ABCG2, and induces inflammasome NLRP3-mediated reduction in inflammatory and apoptotic factors to achieve renal protection. Thus, our findings indicate the therapeutic potential of CQD in HUA with kidney injury.

Factors associated with incidence of acute kidney injury: a Japanese regional population-based cohort study, the Shizuoka study

BACKGROUND

Acute kidney injury (AKI) is a globally critical issue. Most studies about AKI have been conducted in limited settings on perioperative or critically ill patients. As a result, there is little information about the epidemiology and risk factors of AKI in the general population.

METHODS

We conducted a population-based cohort study using the Shizuoka Kokuho Database. We included subjects with records of health checkup results. The observation period for each participant was defined as from the date of insurance enrollment or April 2012, whichever occurred later, until the date of insurance withdrawal or September 2020, whichever was later. Primary outcome was AKI associated with admission based on the ICD-10 code. We described the incidence of AKI and performed a multivariate analysis using potential risk factors selected from comorbidities, medications, and health checkup results.

RESULTS

Of 627,814 subjects, 8044 were diagnosed with AKI (incidence 251 per 100,000 person-years). The AKI group was older, with more males. Most comorbidities and prescribed medications were more common in the AKI group. As novel factors, statins (hazard ratio (HR) 0.84, 95% confidence interval (CI) 0.80-0.89) and physical activity habits (HR 0.79, 95% CI 0.75-0.83) were associated with reduced incidence of AKI. Other variables associated with AKI were approximately consistent with those from previous studies.

CONCLUSIONS

The factors associated with AKI and the incidence of AKI in the general Japanese population are indicated. This study generates the hypothesis that statins and physical activity habits are novel protective factors for AKI.

The Singapore Experience With Uncontrolled Gout: Unmet Needs in the Management of Patients

Gout is the most common type of inflammatory arthritis, and its impact on cardiovascular health and quality of life is often underestimated. The prevalence and incidence of gout are increasing globally. Further, ischemic heart disease (IHD) and chronic kidney disease (CKD) are prevalent in gout patients. Some unmet needs for gout management include physicians' low initiation rate of urate-lowering therapy (ULT) and poor treatment adherence in patients with gout. There is also a lack of randomized controlled trials that establish safe doses of acute and long-term treatment for gout, particularly in patients with IHD and stage 4 CKD and above (including end-stage renal failure). Furthermore, there is also a lack of studies showing optimal serum uric acid (SUA) target and validated clinical outcome measures, including disease activity and remission criteria for gout tailored to treat-to-target approaches and the high cost of newer gout medications. The causal relationship between asymptomatic hyperuricemia or gout with comorbidities such as IHD and CKD has yet to be fully elucidated. There is a pressing need for collaborative international efforts to address the overall suboptimal management of gout.

Mechanism of Xiezhuo Huayu Yiqi Tongluo Formula in the Treatment of Uric Acid Nephropathy Based on Network Pharmacology, Molecular Docking, and In Vivo Experiments

Background

Xiezhuo Huayu Yiqi Tongluo Formula (XHYTF) consists of 14 Chinese herbal medicines. In this study, we investigated the potential mechanism of XHYTF in the treatment of uric acid nephropathy (UAN) through network pharmacology, molecular docking, and in vivo methods.

Methods

Using various pharmacological databases and analysis platforms, information on the active ingredients and targets of Chinese herbal medicine was collected, and UAN disease targets were retrieved using OMIM, Gene Cards, and NCBI. Then common target proteins were integrated. A Drug-Component-Target (D-C-T) map was constructed to screen core compounds and build a protein-protein interaction (PPI) network. Further, Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed for common targets, and a Drug-Component-Target-Pathway (D-C-T-P) network diagram was constructed. The molecular docking simulation was performed to verify the binding affinity between core components and hub targets. Subsequently, the UAN rat model was established, followed by the collection of serum and renal tissues. The expression levels of indicators in the serum were determined using an enzyme-linked immunosorbent assay. The pathological changes of renal tissues were detected using H & E staining and Masson staining. The expression of related proteins in renal tissue was detected by western blot.

Results

In the study, 216 active ingredients and 439 targets in XHYTF were screened, and 868 targets were identified as being related to UAN. Among them, 115 were common targets. Based on the D-C-T network, quercetin, luteolin, β-sitosterol, and stigmasterol were observed to be the key active ingredients of XHYTF that were effective against UAN. The analysis of the PPI network revealed TNF, IL6, AKT1, PPARG, and IL1β as the 5 key targets. GO enrichment analysis revealed that the pathways were mainly concentrated in cell killing, regulation of signaling receptor activity, and other activities. Subsequently, KEGG pathway analysis revealed that multiple signaling pathways, including the HIF-1, PI3K-Akt, IL-17, and other signaling pathways, were closely related to the action of XHYTF. All 5 key targets were confirmed to interact with all core active ingredients. In vivo experiments indicated that XHYTF significantly reduced blood uric acid and creatinine levels, alleviated inflammatory cell infiltration in kidney tissues, reduced the levels of serum inflammatory factors such as TNF-α and IL1β, and ameliorated renal fibrosis in rats with UAN. Finally, western blot revealed decreased levels of PI3K and AKT1 proteins in the kidney, which confirmed the hypothesis.

Conclusion

Collectively, our observations demonstrated that XHYTF significantly protects kidney function, including alleviation of inflammation and renal fibrosis via multiple pathways. This study provided novel insights into the treatment of UAN using traditional Chinese medicines.

Research progress of risk factors and early diagnostic biomarkers of gout-induced renal injury

Gout renal injury has an insidious onset, no obvious symptoms, and laboratory abnormalities in the early stages of the disease. The injury is not easily detected, and in many cases, the patients have entered the renal failure stage at the time of diagnosis. Therefore, the detection of gout renal injury–related risk factors and early diagnostic biomarkers of gout renal injury is essential for the prevention and early diagnosis of the disease. This article reviews the research progress in risk factors and early diagnostic biomarkers of gout renal injury.

Multi metabolomics-based analysis of application of Astragalus membranaceus in the treatment of hyperuricemia

Hyperuricemia (HUA) is a common metabolic disease that is an independent risk factor for comorbidities such as hypertension, chronic kidney disease, and coronary artery disease. The prevalence of HUA has increased over the last several decades with improved living standards and increased lifespans. Metabolites are considered the most direct reflection of individual physiological and pathological conditions, and represent attractive candidates to provide deep insights into disease phenotypes. Metabolomics, a technique used to profile metabolites in biofluids and tissues, is a powerful tool for identification of novel biomarkers, and can be used to provide valuable insights into the etiopathogenesis of metabolic diseases and to evaluate the efficacy of drugs. In this study, multi metabolomics-based analysis of the blood, urine, and feces of rats with HUA showed that HUA significantly altered metabolite profiles. Astragalus membranaceus (AM) and benbromomalone significantly mitigated these changes in blood and feces, but not in urine. Some crucial metabolic pathways including lipid metabolism, lipid signaling, hormones synthesis, unsaturated fatty acid (UFAs) absorption, and tryptophan metabolism, were seriously disrupted in HUA rats. In addition, AM administration exerted better treatment effects on HUA than benbromomalone. Furthermore, additional supplementation with UFAs and tryptophan may also induce therapeutic effects against HUA.

Potential Molecular Mechanisms of Plantain in the Treatment of Gout and Hyperuricemia Based on Network Pharmacology

BACKGROUND

The incidence of gout and hyperuricemia is increasing year by year in the world. Plantain is a traditional natural medicine commonly used in the treatment of gout and hyperuricemia, but the molecular mechanism of its active compounds is still unclear. Based on network pharmacology, this article predicts the targets and pathways of effective components of plantain for gout and hyperuricemia and provides effective reference for clinical medication.

METHOD

Traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP) and SymMap databases were used to screen out the active compounds and their targets in plantain. GeneCards, Therapeutic Target Database (TTD), and Online Mendelian Inheritance in Man (OMIM) databases were used to find the targets corresponding to gout and hyperuricemia. Venn diagram was used to obtain the intersection targets of plantain and diseases. The interaction network of the plantain active compounds-targets-pathways-diseases was constructed by using Cytoscape 3.7.2 software. Finally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were carried out.

RESULT

Seven active compounds were identified by network pharmacological analysis, including dinatin, baicalein, baicalin, sitosterol, 6-OH-luteolin, stigmasterol, and luteolin. Plantain plays a role in gout and hyperuricemia diseases by regulating various biological processes, cellular components, and molecular functions. The core targets of plantain for treating gout are MAPK1, RELA, TNF, NFKBIA, and IFNG, and the key pathways are pathways in cancer, hypoxia-inducible factor-1 (HIF-1) signaling pathway, interleukin (IL)-17 signaling pathway, Chagas disease (American trypanosomiasis), and relaxin signaling pathway. The core targets of plantain for hyperuricemia are RELA, MAPK1, NFKBIA, CASP3, CASP8, and TNF, and the main pathways are pathways in cancer, apoptosis, hepatitis B, IL-17 signaling pathway, and toxoplasmosis.

CONCLUSION

This study explored the related targets and mechanisms of plantain for the treatment of gout and hyperuricemia from the perspective of network pharmacological analysis, reflecting the characteristics of multiple components, multiple targets, and multiple pathways, and it provides a good theoretical basis for the clinical application of plantain.

Effects of Tart Cherry Powder on Serum Uric Acid in Hyperuricemia Rat Model

Hyperuricemia, as a critical risk factor for various adverse clinical outcomes, shows a trend of increasing prevalence among young-aged population. Dietary adjuvant therapy by function foods, such as tart cherry, is promising. Thus, effects of tart cherry powder specialized in hyperuricemia were explored via establishing a hyperuricemia model in Sprague Dawley rats by cotreatment with oteracil potassium and adenine. The results indicated that low dose of tart cherry powder (0.17 g/kg·bw) showed effects on hyperuricemia by slightly decreasing serum uric acid and improving kidney injury, whereas high dose of tart cherry powder (0.50 g/kg·bw) could merely alleviate kidney injury. Meanwhile, adenosine deaminase activity rather than xanthine oxidase activity was affected at low dose, which reveals low dose of tarty cherry powder may be beneficial to hyperuricemia through reduction of ADA activity, and its reported potentials on antioxidation or anti-inflammation provide clues for further study.