Avian renal proximal tubule urate secretion is inhibited by cellular stress-induced AMP-activated protein kinase

Safety evaluation of bempedoic acid: A pharmacovigilance analysis using FDA adverse event reporting system data

BACKGROUND

Bempedoic acid exhibits promising potential in hyperlipidemia therapy and preventing cardiovascular events. However, investigations into its adverse drug reactions remain scant. This study seeks to utilize data mining techniques with the FDA Adverse Event Reporting System (FAERS) database to assess adverse drug events (ADEs) linked to bempedoic acid.

METHODS

Based on the drug's market release timeline, we extracted data from the FAERS database covering the fourth quarter of 2020 through the fourth quarter of 2023 for disproportionality analysis.

RESULTS

This study gathered a total of 5,797,543 adverse event case reports, of which 735 were linked to bempedoic acid. These reports covered 19 System Organ Classes (SOCs) and 22 Preferred Terms (PTs). Predominantly, the musculoskeletal and nervous systems were implicated in these adverse events. By conducting PT-level screening, various signals for ADEs were detected, including myalgia (ROR 30.33, PRR 28.51, IC 4.83, EBGM 28.47), arthralgia (n = 34, ROR 6.34, PRR 6.09, IC 2.61, EBGM 6.09), tendon disorders (ROR 99.57, PRR 98.75, IC 6.62, EBGM 98.28), and dizziness (ROR 3.18, PRR 3.13, IC 1.65, EBGM 3.13). Particularly noteworthy was the hypertensive crisis (ROR 28.63, PRR 28.51, IC 4.83, EBGM 28.47), which exhibited a robust signal strength, an observation previously unreported in clinical studies and drug labeling.

CONCLUSION

While our results are largely consistent with the drug's specifications, several new adverse reaction signals, such as hypertensive crisis, have not been previously documented. Therefore, further investigations are necessary to assess these unlabeled adverse reactions, offering crucial support for the clinical utilization of bempedoic acid.

Isolation, Identification, and Pathogenicity of a Goose Astrovirus Genotype 1 Strain in Goslings in China

Goose astrovirus genotype 1 (GAstV-1) has emerged in goose farms in some provinces of China in recent years and is considered to be one of the pathogens of gout in goslings in China. However, few studies have been conducted on the dynamic distribution, tissue tropism, and pathogenesis of GAstV-1 in goslings. In 2022, an epidemiological investigation of goose astrovirus (GAstV) in goslings was conducted in seven provinces of China. During the investigation, a GAstV-1 designated as GAstV-JSXZ was identified in the kidney of an 8-day-old gosling and was successfully isolated from a goose embryo. The full genome sequence of GAstV-JSXZ was determined using the next-generation sequencing technique. The complete genome of GAstV-JSXZ was 7299-nt-long. Interestingly, the phylogenetic analysis revealed that Chinese GAstV-1 has formed two distinct subgroups based on the ORF 2 genomes, designated GAstV-1 1a and GAstV-1 1b. The GAstV-JSXZ shared the highest identity with GAstV-1 1a strain FLX and TZ03 in nucleotides (ORF1a: 98.3-98.4%; ORF1b: 92.3-99.1%; ORF2: 95.8-98.8%) and amino acid sequences (ORF1a: 99.4-99.5%; ORF1b: 98.2-98.8%; ORF2: 97.0-99.4%). To evaluate the pathogenicity of GAstV-1, 1-day-old goslings were inoculated with the virus by oral and subcutaneous injection routes, respectively. The results revealed that the virus causes extensive pathological organ damage, especially in the kidney, liver, and thymus. Virus-specific genomic RNA could be detected in the cloacal swabs and tissues of infected goslings throughout the experiment. The viral copy numbers examined in the kidney and intestine were the highest, followed by the liver and spleen. These results are likely to provide a new understanding of the pathogenicity of GAstV-1 in geese.

AMP-activated protein kinase α2 contributes to acute and chronic hyperuricemic nephropathy via renal urate deposition in a mouse model

Hyperuricemia can induce acute and chronic kidney damage, but the pathological mechanism remains unclear. The potential role of AMP-activated protein kinase (AMPK) α2 in hyperuricemia-induced renal injury was investigated in this study. Acute and chronic hyperuricemic nephropathy was induced by administering intraperitoneal injections of uric acid and oxonic acid to AMPK α2 knockout and wild-type mice. Changes in renal function, histopathology, inflammatory cell infiltration, renal interstitial fibrosis, and urate deposition were analyzed. In both acute and chronic hyperuricemic nephropathy mouse models, knockout of AMPK α2 significantly reduced serum creatinine levels and renal pathological changes. The tubular expression of kidney injury molecule-1 was also reduced in hyperuricemic nephropathy mice deficient in AMPK α2. In addition, knockout of AMPK α2 significantly suppressed the infiltration of renal macrophages and progression of renal interstitial fibrosis in mice with chronic hyperuricemic nephropathy. Knockout of AMPK α2 reduced renal urate crystal deposition, probably through increasing the expression of the uric acid transporter, multidrug resistance protein 4. In summary, AMPK α2 is involved in acute and chronic hyperuricemia-induced kidney injury and may be associated with increased urate crystal deposition in the kidney.

Effect of Bempedoic Acid on Serum Uric Acid and Related Outcomes: A Systematic Review and Meta-analysis of the available Phase 2 and Phase 3 Clinical Studies

INTRODUCTION

Bempedoic acid (ETC-1002) is a first-in-class lipid-lowering agent recently approved by the United States (US) Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for commercialization.

OBJECTIVE

The aim was to assess, through a systematic review of the literature and a meta-analysis of the available phase 2 and phase 3 clinical studies, the effect of treatment with bempedoic acid on serum uric acid (SUA) concentration. Secondary outcomes were treatment-related variations in creatinine serum level and incidence of gout.

METHODS

A systematic literature search in SCOPUS, PubMed Medline, ISI Web of Science and Google Scholar databases was conducted up to November 13th, 2019, in order to identify clinical trials potentially eligible for the meta-analysis. Effect sizes were expressed as absolute mean differences (MDs) and 95% confidence intervals (CIs).

RESULTS

Data were pooled from four clinical studies comprising ten arms, which included overall 3369 subjects, with 2213 in the active-treatment arm and 1156 in the control one. Meta-analysis of data suggested that treatment with bempedoic acid is related to a significant increase in SUA (MD 0.73, 95% CI 0.54-0.91, P < 0.001), serum creatinine (MD 0.04, 95% CI 0.03-0.05, P < 0.001) and the incidence of gout (odds ratio 3.56, 95% CI 1.24-10.19, P = 0.018). The relatively small number of subjects involved in the studies and the exclusion of patients with renal impairment from the clinical trials are important limitations of the meta-analysis. However, our data indicate potential safety issues with bempedoic acid and suggest that further studies are performed both to elucidate the pathogenetic mechanisms underlying these associations and to verify the long-term safety of this treatment.

CONCLUSION

Bempedoic acid seems to have unfavourable effects on SUA, creatinine level and the incidence of gout. The ongoing Cardiovascular Outcomes Trial (CVOT) will explore the longer-term safety of treatment with bempedoic acid and clarify its effect on cardiovascular events and mortality.

PROSPERO DATABASE REGISTRATION

CRD42019146126.

Goose astrovirus infection affects uric acid production and excretion in goslings

In 2018, a new goose astrovirus (GAstrV) was reported in China, which causes 2 to 20% deaths in 4- to 16-day-old goslings causing great damages to the livestock industry. Gout is the typical feature of GAstrV infection in goslings. However, the mechanism of gout formation remains unclear. In the present study, 2-day-old goslings were infected intramuscularly with GAstrV for 14 D. One quarter of the infected goslings died, and typical gout pathological changes were found in the dead infected goslings. Pathological changes were observed in the morphology of the kidney and liver, such as degeneration, necrosis, and inflammatory cell infiltration. Accordingly, a high virus load was found in both organs. The serum level of uric acid in the inoculated goslings was higher, whereas no differences were found in levels of creatinine, calcium, and phosphorus. Moreover, the xanthine dehydrogenase (XOD) and adenosine deaminase (ADA) activities and the mRNA levels of xanthine dehydrogenase, adenosine deaminase, phosphoribosyl pyrophosphate amidotransferase, and phosphoribosyl pyrophosphate synthetase 1 in livers increased, wheres the multidrug resistance-associated protein 4 mRNA level and Na-K-ATPase activity in the kidneys decreased. These results showed that GAstrV infection could cause lesions on the liver and kidney and then increase the expression or activity of enzymes related to uric acid production in the liver and decrease renal excretion function, which contribute to hyperuricemia and gout formation.

Uric acid transporters BCRP and MRP4 involved in chickens uric acid excretion

Background

Breast cancer resistance protein (BCRP) and multidrug resistance protein 4 (MRP4) are involved in uric acid excretion in humans and mice. Despite evidence suggesting that renal proximal tubular epithelial cells participate in uric acid excretion in chickens, the roles of BCRP and MRP4 therein remain unclear. This study evaluated the relationship between BCRP and MRP4 expression and renal function in chickens.

Results

Sixty laying hens were randomly divided into four treatment groups: a control group (NC) fed a basal diet; a sulfonamide-treated group (SD) fed the basal diet and supplemented with sulfamonomethoxine sodium via drinking water (8 mg/L); a fish meal group (FM) fed the basal diet supplemented with 16% fishmeal; and a uric acid injection group (IU) fed the basal diet and intraperitoneally injected with uric acid (250 mg/kg body weight). The results showed that serum uric acid, creatinine, and blood urea nitrogen levels were significantly higher in the SD and IU, but not FM, than in the NC groups. Renal tubular epithelial cells in the SD and IU groups were damaged. Liver BCRP and MRP4 mRNA and protein levels were significantly decreased in the SD and IU groups, but slightly increased in the FM group. In the SD group, BCRP and MRP4 were significantly increased in the ileum and slightly increased in the kidney. In the FM group, BCRP and MRP4 were significantly increased in the kidney and slightly increased in the ileum. In the IU group, BCRP and MRP4 were significantly increased in the kidney and ileum. BCRP and MRP4 expression in the jejunum was not affected by the treatments.

Conclusion

Together, these results demonstrate that BCRP and MRP4 are involved in renal and intestinal uric acid excretion in chickens and that BCRP is positively related to MRP4 expression. Further, impairment of renal function results in an increase in serum uric acid as well as a compensatory increase in BCRP and MRP4 in the ileum; however, under normal renal function, renal BCRP and MRP4 are the main regulators of uric acid excretion.

Association between low dietary zinc and hyperuricaemia in middle-aged and older males in China: a cross-sectional study

OBJECTIVE

To examine the associations between dietary zinc intake and hyperuricaemia.

DESIGN

Cross-sectional study.

SETTING

This study was conducted in a health examination centre of China.

PARTICIPANTS

A total of 5168 middle-aged and older participants (aged 40 years or above) (2697 men and 2471 women) were included.

OUTCOME MEASURES

Dietary zinc intake was assessed using a validated semiquantitative food frequency questionnaire. Hyperuricaemia was defined as uric acid ≥416 µmol/L for males and ≥360 µmol/L for females.

RESULTS

For males, the prevalence of hyperuricaemia was 22.9%. After adjusting for age, body mass index (BMI) and energy intake, the ORs were 0.68 (95% CI 0.45 to 0.92) in the second quintile, 0.63 (95% CI 0.45 to 0.89) in the third quintile, 0.68 (95% CI 0.46 to 1.00) in the fourth quintile and 0.55 (95% CI 0.35 to 0.87) in the fifth quintile comparing the lowest quintile of Zn intake, respectively (p for trend=0.03). In the multivariable adjusted model, the relative odds of hyperuricaemia were significantly decreased by 0.71 times in the second quintile of zinc intake (OR 0.71, 95% CI 0.52 to 0.98), 0.64 times in the third quintile (OR 0.65, 95% CI 0.44 to 0.94) and 0.55 times in the fifth quintile (OR 0.56, 95% CI 0.32 to 0.97) compared with those in the lowest quintile, and p for trend was 0.064. For females, the prevalence of hyperuricaemia was 10.0%, and unadjusted, minimally adjusted as well as multivariable adjusted ORs all suggested no significant association between dietary zinc intake and hyperuricaemia.

CONCLUSIONS

The findings of this cross-sectional study indicated that dietary zinc intake was inversely associated with hyperuricaemia in middle-aged and older males, but not in females. The association was significant after considering the influence of age, BMI and energy intake, and after that, minimum adjustment remained independent of further confounding factors such as vitamin C intake, alcohol drinking status and nutrient supplementation.

Urate transporters in the genomic era

PURPOSE OF REVIEW

Recent advances in genome technology have provided us with a list of molecules affecting urate handling in humans, many of which are unlikely to be identified through traditional physiological approach alone. Although this article is focused on urate, this can be viewed as a successful model of genomics-physiology collaboration.

RECENT FINDINGS

URATv1/GLUT9 (SLC2A9) is shown to play a critical role in urate reabsorption at the proximal tubule, probably more prominent than its partner URAT1 (SLC22A12). The major site of action of ABCG2 (ABCG2), an influential urate secretion transporter, has been shown to be the intestine rather than the kidney proximal tubule. Accordingly, hypofunction of ABCG2 leads to increased fractional excretion of urate, a finding traditionally interpreted as overproduction hyperuricemia. Some SLC17 family members secrete urate in the kidney or intestine. OAT2 (SLC22A7) may take up urate from blood to the proximal tubular cell. In addition, how a common single-nucleotide polymorphisms in ABCG2 affects its function has been elucidated.

SUMMARY

A finer grained picture of urate handling in the human body is now emerging, which will help choosing novel targets for urate-lowering therapy.

AMP-activated protein kinase regulation of kidney tubular transport

PURPOSE OF REVIEW

The coupling of epithelial transport to underlying metabolic status is critical because solute transport processes normally consume a large proportion of total cellular energy. Recently, AMP-activated protein kinase (AMPK) has emerged as a critical transport regulator in tissues throughout the body. This review summarizes the role of AMPK in the regulation of renal epithelial transport, updates the growing list of AMPK transport protein targets and regulatory mechanisms, and discusses the potential clinical significance of this regulation in normal and disease states.

RECENT FINDINGS

Recent work has identified several new ion channels, transporters, and pumps that are regulated by AMPK in the kidney, and a better understanding of the mechanisms for the AMPK-dependent regulation of membrane transport proteins is emerging. Treatment with AMPK activators may be beneficial in preventing deleterious effects in the kidney in the setting of various diseases, including acute ischemia, diabetes mellitus and polycystic kidney disease, via mechanisms that depend at least partly on the regulatory effects of AMPK on solute transport.

SUMMARY

The energy-sensing kinase AMPK has a growing list of pleiotropic effects on cells and tissues, including its key role in the coupling of membrane transport to metabolic status in epithelial tissues like the kidney. AMPK is also involved in the coordination of hormonal, inflammatory, and other cellular stress pathway signals to produce an integrated effect on tubular transport. Identifying and characterizing new transport protein targets of AMPK should yield valuable new insights into various physiological and pathological processes in the kidney.