Interaction of the GCKR and A1CF loci with alcohol consumption to influence the risk of gout

Building capacity to conduct genetic epidemiology research on hyperuricaemia and gout in an Indigenous community in Guam

Background

Gout, the most common inflammatory arthritis disease, and hyperuricaemia onset are influenced by environmental and genetic factors. We sought to investigate these factors in an Indigenous community in Guam.

Methods

In this cross-sectional study, the University of Guam led the qualitative inquiry with the native community, training (pre-screening of participants, data collection methods, and biospecimen handling), study implementation (outreach and recruitment, data collection, and DNA extraction and quantification), and qualitative and epidemiologic data analyses. Recruitment targets were based on demographic representation in current census data. The University of Otago collaborated on ethics guidance, working with Indigenous communities, and led the genetic sequencing and genetic data analysis. Participants were recruited in Guam from Fall 2019 to Spring 2022.

Results

Of the 359 participants, most self-identified as Native CHamorus (61.6%) followed by Other Micronesians (22.0%), and Filipinos (15.6%). The prevalence of metabolic conditions from highest to lowest were obesity (55.6%), hyperuricaemia (36.0%), hypertension (27.8%), gout (23.0%), diabetes (14.9%), cardiovascular disease (8.4%), kidney disease (7.3%), and liver disease (3.4%). Compared to Filipinos and Other Micronesians, significantly more CHamorus had hyperuricaemia (42.1% versus 26.8% in Filipinos and 25.3% in Other Micronesians), gout (28.5% versus 21.4% and 8.9%), diabetes (19.5% versus 8.9% and 6.3%), and hypertension (33.9% versus 19.6% and 16.5%).

Conclusions

We estimated the prevalence of metabolic conditions, especially gout and hyperuricaemia, and found statistical differences among major ethnic groups in Guam, all while obtaining the Indigenous community's feedback on the genetic study and building gout research capacity. The results of ongoing genetic sequencing will be used to understand molecular causes of gout in Guam.

Interaction of genetic variation at ADH1B and MLXIPL with alcohol consumption for elevated serum urate level and gout among people of European ethnicity

BACKGROUND

Alcohol consumption is a risk factor for hyperuricaemia and gout. Multiple single-nucleotide polymorphisms (SNPs) have been identified as associated with both alcohol consumption and serum urate or gout in separate genome-wide association studies (GWAS). This study aimed to identify and characterise interactions between these shared signals of genetic association and alcohol consumption for serum urate level, hyperuricaemia, and gout.

METHODS

This research was conducted using the UK Biobank resource. The association of alcohol consumption with serum urate and gout was tested among 458,405 European participants. Candidate SNPs were identified by comparing serum urate, gout, and alcohol consumption GWAS for shared signals of association. Multivariable-adjusted linear and logistic regression analyses were conducted with the inclusion of interaction terms to identify SNP-alcohol consumption interactions for association with serum urate level, hyperuricaemia, and gout. The nature of these interactions was characterised using genotype-stratified association analyses.

RESULTS

Alcohol consumption was associated with elevated serum urate and gout. For serum urate level, non-additive interactions were identified between alcohol consumption and rs1229984 at the ADH1B locus (P = 3.0 × 10-44) and rs6460047 at the MLXIPL locus (P = 1.4 × 10-4). ADH1B also demonstrated interaction with alcohol consumption for hyperuricaemia (P = 7.9 × 10-13) and gout (P = 8.2 × 10-9). Beer intake had the most significant interaction with ADH1B for association with serum urate and gout among men, while wine intake had the most significant interaction among women. In the genotype-stratified association analyses, ADH1B and MLXIPL were associated with serum urate level and ADH1B was associated with hyperuricaemia and gout among consumers of alcohol but not non-consumers.

CONCLUSIONS

In this large study of European participants, novel interactions with alcohol consumption were identified at ADH1B and MLXIPL for association with serum urate level and at ADH1B for association with hyperuricaemia and gout. The association of ADH1B with serum urate and gout may occur through the modulation of alcohol metabolism rate among consumers of alcohol.

Familial Risk of Gout and Interaction With Obesity and Alcohol Consumption: A Population-Based Cohort Study in Korea

OBJECTIVE

Population-based studies of the familial aggregation of gout are scarce, and gene/environment interactions are not well studied. This study was undertaken to evaluate the familial aggregation of gout as well as assess interactions between family history and obesity or alcohol consumption on the development of gout.

METHODS

Using the Korean National Health Insurance database, which includes information regarding familial relationships and risk factor data, we identified 5,524,403 individuals from 2002 to 2018. Familial risk was calculated using hazard ratios (HRs) with 95% confidence intervals (95% CIs) to compare the risk in individuals with and those without affected first-degree relatives. Interactions between family history and obesity/alcohol consumption were assessed on an additive scale using the relative excess risk due to interaction (RERI).

RESULTS

Individuals with a gout-affected first-degree relative had a 2.42-fold (95% CI 2.39, 2.46) increased risk of disease compared to those with unaffected first-degree relatives. Having both a family history of gout and being either overweight or having moderate alcohol consumption was associated with a markedly increased risk of disease, with HRs of 4.39 (95% CI 4.29, 4.49) and 2.28 (95% CI 2.22, 2.35), respectively, which exceeded the sum of their individual risks but was only statistically significant in overweight individuals (RERI 0.96 [95% CI 0.85, 1.06]). Obese individuals (RERI 1.88 [95% CI 1.61, 2.16]) and heavy drinkers (RERI 0.36 [95% CI 0.20, 0.52]) had a more prominent interaction compared to overweight individuals and moderate drinkers, suggesting a dose-response interaction pattern.

CONCLUSION

Our findings indicate the possibility of an interaction between gout-associated genetic factors and obesity/alcohol consumption.

Uric acid en route to gout

Gout and hyperuricemia (HU) have generated immense attention due to increased prevalence. Gout is a multifactorial metabolic and inflammatory disease that occurs when increased uric acid (UA) induce HU resulting in monosodium urate (MSU) crystal deposition in joints. However, gout pathogenesis does not always involve these events and HU does not always cause a gout flare. Treatment with UA-lowering therapeutics may not prevent or reduce the incidence of gout flare or gout-associated comorbidities. UA exhibits both pro- and anti-inflammation functions in gout pathogenesis. HU and gout share mechanistic and metabolic connections at a systematic level, as shown by studies on associated comorbidities. Recent studies on the interplay between UA, HU, MSU and gout as well as the development of HU and gout in association with metabolic syndromes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular, renal and cerebrovascular diseases are discussed. This review examines current and potential therapeutic regimens and illuminates the journey from disrupted UA to gout.

The association between the CCDC88A gene polymorphism at rs1437396 and alcohol use disorder, with or without major depression disorder

Girdin is a protein involved in neuronal migration and hippocampal development. It is encoded by the coiled-coil domain-containing 88A (CCDC88A) gene, located on the short arm of chromosome 2 (2p). The CCDC88A gene is modulated by the intergenic single-nucleotide polymorphism (SNP) of the rs1437396, situated 9.5 kb downstream from its transcription stop site. As recent genome-wide research has associated the T allele of the SNP with increased risk of alcohol use disorder (AUD), we wanted to validate this finding in an independent cohort and to test further for an association with comorbid major depressive disorder (MDD). The study included 226 AUD patients (AUD group), 53 patients with comorbid MDD, and 391 controls selected randomly. The participants were genotyped for the rs1437396 polymorphism using the real-time polymerase chain reaction. The association between the rs1437396 polymorphism and increased risk of AUD and AUD+MDD was tested with logistic regression. Our results show significantly higher frequency of the T risk allele in the AUD group (p=0.027) and even higher in the AUD+MDD group (p=0.016). In conclusion, this is the first study that has validated the association between the rs1437396 polymorphism of the CCDC88A gene and AUD with or without MDD. Studies on larger samples of patients are needed to further investigate the mechanism of this association.

Susceptibility genes of hyperuricemia and gout

Gout is a chronic metabolic disease that seriously affects human health. It is also a major challenge facing the world, which has brought a heavy burden to patients and society. Hyperuricemia (HUA) is the most important risk factor for gout. In recent years, with the improvement of living standards and the change of dietary habits, the incidence of gout in the world has increased dramatically, and gradually tends to be younger. An increasing number of studies have shown that gene mutations may play an important role in the development of HUA and gout. Therefore, we reviewed the existing literature and summarized the susceptibility genes and research status of HUA and gout, in order to provide reference for the early diagnosis, individualized treatment and the development of new targeted drugs of HUA and gout.

Trends in the Contribution of Genetic Susceptibility Loci to Hyperuricemia and Gout and Associated Novel Mechanisms

Hyperuricemia and gout are complex diseases mediated by genetic, epigenetic, and environmental exposure interactions. The incidence and medical burden of gout, an inflammatory arthritis caused by hyperuricemia, increase every year, significantly increasing the disease burden. Genetic factors play an essential role in the development of hyperuricemia and gout. Currently, the search on disease-associated genetic variants through large-scale genome-wide scans has primarily improved our understanding of this disease. However, most genome-wide association studies (GWASs) still focus on the basic level, whereas the biological mechanisms underlying the association between genetic variants and the disease are still far from well understood. Therefore, we summarized the latest hyperuricemia- and gout-associated genetic loci identified in the Global Biobank Meta-analysis Initiative (GBMI) and elucidated the comprehensive potential molecular mechanisms underlying the effects of these gene variants in hyperuricemia and gout based on genetic perspectives, in terms of mechanisms affecting uric acid excretion and reabsorption, lipid metabolism, glucose metabolism, and nod-like receptor pyrin domain 3 (NLRP3) inflammasome and inflammatory pathways. Finally, we summarized the potential effect of genetic variants on disease prognosis and drug efficacy. In conclusion, we expect that this summary will increase our understanding of the pathogenesis of hyperuricemia and gout, provide a theoretical basis for the innovative development of new clinical treatment options, and enhance the capabilities of precision medicine for hyperuricemia and gout treatment.

Healthy lifestyle counteracts the risk effect of genetic factors on incident gout: a large population-based longitudinal study

BACKGROUND

Risk genes linked to the development of gout have been identified, and lifestyle factors are related to gout risk. It remains unclear whether healthy lifestyle factors can mitigate the genetic risk of gout. Therefore, we aimed to explore whether and to what extent a healthy lifestyle can mitigate the risk of gout related to genetic factors.

METHODS

Within the UK Biobank, 416,481 gout-free participants (aged 37-74) were identified at baseline. Polygenic risk for gout was assessed and categorized as low (lowest tertile), middle (tertile 2), and high (highest tertile). Healthy lifestyle factors included no/moderate alcohol consumption, no smoking, physical activity, and a healthy diet. Participants were categorized into three groups according to their number of healthy lifestyle factors: unfavorable (0 or 1), intermediate (any 2), and favorable (3 or 4). Data were analyzed using Cox proportional hazard models.

RESULTS

Over the follow-up (median: 12.1 years), 6206 participants developed gout. Compared to low genetic risk, the hazard ratios (HRs) and 95% confidence intervals (CIs) of gout was 1.44 (1.35-1.54) for middle and 1.77 (1.66-1.89) for high genetic risk. The HRs (95% CIs) of gout were 0.63 (0.59-0.67) for a favorable lifestyle and 0.79 (0.75-0.85) for an intermediate lifestyle, compared to an unfavorable lifestyle. In joint effect analysis, compared to participants with low genetic predisposition and a favorable lifestyle, the HRs (95% CIs) of gout were 2.39 (2.12-2.70)/3.12 (2.79-3.52) in those with middle and high genetic predisposition plus unfavorable lifestyle profiles, and 1.53 (1.35-1.74)/1.98 (1.75-2.24) for those with middle and high genetic predisposition plus favorable lifestyle profiles, respectively. Moreover, compared to an unfavorable lifestyle, the HRs of gout related to a favorable lifestyle was 0.64 (95% CI, 0.56-0.73) for low genetic risk, 0.65 (95% CI, 0.58-0.72) for middle genetic risk, and 0.62 (95% CI, 0.57-0.69) for high genetic risk. There was a significant additive interaction between unfavorable lifestyle and high genetic risk on gout.

CONCLUSIONS

Healthy lifestyle was associated with a lower risk of gout and may attenuate the risk of gout related to genetic factors by almost a third.

Association between glucokinase regulator gene polymorphisms and serum uric acid levels in Taiwanese adolescents

The glucokinase regulator gene (GCKR) is located on chromosome 2p23. It plays a crucial role in maintaining plasma glucose homeostasis and metabolic traits. Recently, genome-wide association studies have revealed a positive association between hyperuricemia and GCKR variants in adults. This study investigated this genetic association in Taiwanese adolescents. Data were collected from our previous cross-sectional study (Taipei Children Heart Study). The frequencies of various genotypes (CC, CT, and TT) or alleles (C and T) of the GCKR intronic single-nucleotide polymorphism (SNP) rs780094 and the coding SNP rs1260326 (Pro446Leu, a common 1403C-T transition) were compared between a total of 968 Taiwanese adolescents (473 boys, 495 girls) with hyperuricemia or normal uric acid levels on the basis of gender differences. Logistic and linear regression analyses explored the role of GCKR in abnormal uric acid (UA) levels. Boys had higher UA levels than girls (6.68 ± 1.29 and 5.23 ± 0.95 mg/dl, respectively, p < 0.001). The analysis of both SNPs in girls revealed that the T allele was more likely to appear in patients with hyperuricemia than the C allele. After adjusting for confounders, the odds ratio (OR) for hyperuricemia incidence in the TT genotype was 1.75 (95% confidence interval [CI] 1.02–3.00), which was higher than that in the C allele carriers in rs1260326 in the girl population. Similarly, the TT genotypes had a higher risk of hyperuricemia, with an OR of 2.29 (95% CI 1.11–4.73) for rs1260326 and 2.28 (95% CI 1.09–4.75) for rs780094, than the CC genotype in girl adolescents. The T (Leu446) allele of GCKR rs1260326 polymorphism is associated with higher UA levels in Taiwanese adolescent girls.

Association and interaction between dietary patterns and gene polymorphisms in Liangshan residents with hyperuricemia

Hyperuricemia (HUA) is associated with dietary and genetic factors. However, studies on dietary patterns and their interaction effect with genes on the risk of HUA are limited. We aimed to explore the association between dietary patterns and HUA, and dietary patterns—gene interactions on the risk of HUA. A population-based cross-sectional study was conducted in adults aged 18 and older in Liangshan Yi Autonomous Prefecture of China. Dietary consumption was collected using a standard Food Frequency Questionnaire. Vein blood samples were collected after overnight fasting, and DNA was extracted from peripheral blood leukocytes. Dietary patterns were derived using principal component and factor analysis. Of the 2646 participants, the prevalence of HUA was 26.8%. Three dietary patterns were classified. Of them, a dietary pattern with higher meat consumption (defined as meat-based) had the strongest association with HUA than a dietary pattern with plant-based or local special diet-based. A higher frequency of T allele at ABCG2 rs2231142 and SLC2A9 rs11722228 loci was observed in participants with HUA than those without HUA. An additive interaction of meat-based dietary pattern with rs2231142 locus was significantly associated with an increased risk of HUA. The relative excess risks of interaction, attributable proportion of interaction, and synergy index (S) were 0.482 (95% CI: 0.012–0.976), 0.203 (95% CI: 0.033–0.374), and 1.544 (95% CI: 1.012–2.355), respectively. In conclusion, a dietary pattern with meat-based was significantly associated with an increased risk of HUA. There was an additive interaction between a meat-based dietary pattern and the ABCG2 rs2231142 locus. Individuals with rs2231142 T allele were at higher risk of HUA than those with rs2231142 GG allele.

Genetic risk of hyperuricemia in hypertensive patients associated with antihypertensive drug therapy: a longitudinal study

Elevated serum uric acid (UA) level has been shown to be influenced by multiple genetic variants, but it remains uncertain how UA‐associated variants differ in their influence on hyperuricemia risk in people taking antihypertensive drugs. We examined a total of 43 UA‐related variants at 29 genes in 1840 patients with hypertension from a community‐based longitudinal cohort during a median 2.25‐year follow‐up (including 1031 participants with normal UA, 440 prevalent hyperuricemia at baseline, and 369 new‐onset hyperuricemia). Compared with the wild‐type genotypes, patients carrying the SLC2A9 rs3775948G allele or the rs13129697G allele had decreased risk of hyperuricemia, while patients carrying the SLC2A9 rs11722228T allele had increased risk of hyperuricemia, after adjustment for cardiovascular risk factors and correction for multiple comparisons; moreover, these associations were modified by the use of diuretics, β‐blockers, or angiotensin converting enzyme inhibitors. The rs10821905A allele of A1CF gene was associated with increased risk of hyperuricemia, and this risk was enhanced by diuretics use. The studied variants were not observed to confer risk for incident cardiovascular events during the follow‐up. In conclusion, the genes SLC2A9 and A1CF may serve as potential genetic markers for hyperuricemia risk in relation to antihypertensive drugs therapy in Chinese hypertensive patients.

The genetic basis of urate control and gout: Insights into molecular pathogenesis from follow-up study of genome-wide association study loci

This review focuses on the post-genome-wide association study (GWAS) era in gout, i.e., the translation of GWAS genetic association signals into biologically informative knowledge. Analytical and experimental follow-up of individual loci, based on the identification of causal genetic variants, reveals molecular pathogenic pathways. We summarize in detail the largest GWAS in urate to date, then we review follow-up studies and molecular insights from ABCG2, HNF4A, PDZK1, MAF, GCKR, ALDH2, ALDH16A1, SLC22A12, SLC2A9, ABCC4, and SLC22A13, including the role of insulin signaling. One common factor in these pathways is the importance of transcriptional control, including the HNF4α transcription factor. The new molecular knowledge reveals new targets for intervention to manage urate levels and prevent gout.

The role of alcohol consumption in pathogenesis of gout

Alcohol is recognized a risk factor for increased uric acid and gout flare. The aim of the study was to review the literature in order to find out what is the role of alcohol consumption in pathogenesis of gout. A search in PubMed, Google Scholar, Medline Complete database was performed in January 2021. The databases were searched with the phrases: "uric acid and alcohol," "alcoholic beverages and gout," "hyperuricemia and alcoholic beverages consumption" published between 2000 and 2021. A total of 2642 results were found. The 99 non-duplicate citations were screened. Then 81 articles were excluded after abstract screen. After that 18 articles were retrieved. Eventually 15 articles were included for systematic review. Several authors see the positive correlation between beer or distilled spirits consumption and gout. Some include wine to the list of triggers of gout. Others state that moderate wine consumption protects from gout attacks due to antioxidants and phytoestrogen content. Majority noticed the relationship between episodic alcohol consumption and gout attacks. Episodic alcohol intake triggers gout attacks, regardless of type of alcohol. Thus, individuals with established gout and pre-existing risk factors should limit all types of alcohol intake to prevent gout episodes.

Why Does Hyperuricemia Not Necessarily Induce Gout?

Hyperuricemia is a risk factor for gout. It has been well observed that a large proportion of individuals with hyperuricemia have never had a gout flare(s), while some patients with gout can have a normuricemia. This raises a puzzle of the real role of serum uric acid (SUA) in the occurrence of gout flares. As the molecule of uric acid has its dual effects in vivo with antioxidant properties as well as being an inflammatory promoter, it has been placed in a delicate position in balancing metabolisms. Gout seems to be a multifactorial metabolic disease and its pathogenesis should not rely solely on hyperuricemia or monosodium urate (MSU) crystals. This critical review aims to unfold the mechanisms of the SUA role participating in gout development. It also discusses some key elements which are prerequisites for the formation of gout in association with the current therapeutic regime. The compilation should be helpful in precisely fighting for a cure of gout clinically and pharmaceutically.

Both variants of A1CF and BAZ1B genes are associated with gout susceptibility: a replication study and meta-analysis in a Japanese population

Gout is a common type of acute arthritis that results from elevated serum uric acid (SUA) levels. Recent genome-wide association studies (GWASs) have revealed several novel single nucleotide polymorphism (SNPs) associated with SUA levels. Of these, rs10821905 of A1CF and rs1178977 of BAZ1B showed the greatest and the second greatest significant effect size for increasing SUA level in the Japanese population, but their association with gout is not clear. We examined their association with gout using 1411 clinically-defined Japanese gout patients and 1285 controls, and meta-analyzed our previous gout GWAS data to investigate any association with gout. Replication studies revealed both SNPs to be significantly associated with gout (P = 0.0366, odds ratio [OR] with 95% confidence interval [CI]: 1.30 [1.02-1.68] for rs10821905 of A1CF, P = 6.49 × 10^-3, OR with 95% CI: 1.29 [1.07-1.55] for rs1178977 of BAZ1B). Meta-analysis also revealed a significant association with gout in both SNPs (P_meta = 3.16 × 10^-4, OR with 95% CI: 1.39 [1.17-1.66] for rs10821905 of A1CF, P_meta = 7.28 × 10^-5, OR with 95% CI 1.32 [1.15-1.51] for rs1178977 of BAZ1B). This study shows the first known association between SNPs of A1CF, BAZ1B and clinically-defined gout cases in Japanese. Our results also suggest a shared physiological/pathophysiological background between several populations, including Japanese, for both SUA increase and gout susceptibility. Our findings will not only assist the elucidation of the pathophysiology of gout and hyperuricemia, but also suggest new molecular targets.

The RNA-Binding Protein A1CF Regulates Hepatic Fructose and Glycerol Metabolism via Alternative RNA Splicing

The regulation of hepatic gene expression has been extensively studied at the transcriptional level; however, the control of metabolism through posttranscriptional gene regulation by RNA-binding proteins in physiological and disease states is less understood. Here, we report a major role for the hormone-sensitive RNA-binding protein (RBP) APOBEC1 complementation factor (A1CF) in the generation of hepatocyte-specific and alternatively spliced transcripts. Among these transcripts are isoforms for the dominant and high-affinity fructose-metabolizing ketohexokinase C and glycerol kinase, two key metabolic enzymes that are linked to hepatic gluconeogenesis and found to be markedly reduced upon hepatic ablation of A1cf. Consequently, mice lacking A1CF exhibit improved glucose tolerance and are protected from fructose-induced hyperglycemia, hepatic steatosis, and development of obesity. Our results identify a previously unreported function of A1CF as a regulator of alternative splicing of a subset of genes influencing hepatic glucose production through fructose and glycerol metabolism.

Recent Efforts to Dissect the Genetic Basis of Alcohol Use and Abuse

Alcohol use disorder (AUD) is defined by several symptom criteria, which can be dissected further at the genetic level. Over the past several years, our understanding of the genetic factors influencing alcohol use and abuse has progressed tremendously; numerous loci have been implicated in different aspects of alcohol use. Previously known associations with alcohol-metabolizing enzymes (ADH1B, ALDH2) have been replicated definitively. In addition, novel associations with loci containing the genes KLB, GCKR, CRHR1, and CADM2 have been reported. Downstream analyses have leveraged these genetic findings to reveal important relationships between alcohol use behaviors and both physical and mental health. AUD and aspects of alcohol misuse have been shown to overlap strongly with psychiatric disorders, whereas aspects of alcohol consumption have shown stronger links to metabolism. These results demonstrate that the genetic architecture of alcohol consumption only partially overlaps with the genetics of clinically defined AUD. We discuss the limitations of using quantitative measures of alcohol use as proxy measures for AUD, and we outline how future studies will require careful phenotype harmonization to properly capture the genetic liability to AUD.

Genetic advances in gout: potential applications in clinical practice

PURPOSE OF REVIEW

Many novel genetic associations in the field of hyperuricaemia and gout have been described recently. This review discusses advances in gout genetics and their potential clinical applications.

RECENT FINDINGS

Genome-wide association studies have identified approximately 30 serum urate-associated loci, some of which represent targets for drug development in gout. Some genes implicated in initiating the inflammatory response to deposited crystals in gout flares have also been described. In addition, genetic studies have been used to understand the link between hyperuricaemia and other comorbidities, particularly cardiometabolic diseases. ABCG2 has been established as a key genetic determinant in the onset of gout, and plays a role in the progression and severity of disease. Recent pharmacogenetic studies have also demonstrated the association between ABCG2 and poor response to allopurinol, and the link between HLA-B58:01 genotype and adverse drug reactions to allopurinol.

SUMMARY

Advances in gout genetics have provided important molecular insights into disease pathogenesis, better characterized the pharmacogenetics of allopurinol, and raised the possibility of using genetic testing to provide personalized treatment for patients. Prospective studies are now needed to clarify whether genetic testing in gout provides further benefit when added to established clinical management.

A1CF-promoted colony formation and proliferation of RCC depends on DKK1-MEK/ERK signal axis

The function and mechanism of RNA editing proteins have been extensively studied, but its association with cellular processes and signaling pathways remained unaddressed. Here, we explored the function of RNA editing complementary protein- Apobec-1 Complementation Factor (A1CF) in the proliferation and colony formation of renal cell carcinoma (RCC) cells. Decreased A1CF expression inhibits the proliferation and colony formation of 786-O cells; and further signaling pathway screening demonstrated that A1CF increases ERK activation and DKK1 expression. Moreover, knockdown of DKK1 has similar phenotypes with A1CF deficiency in 786-O cells on cell proliferation and colony formation and ERK activation. Decreasing of DKK1 expression reduces the phosphorylation of ERK1/2 and MEK1/2 increased by A1CF overexpression; further, inhibiting of the phosphorylation of MEK1/2 by U0126 also decreases the ERK activation upregulated by A1CF overexpression. Deficiency of DKK1 or U0126 treatment suppresses the cell proliferation promoted by A1CF overexpression in 786-O cells; furthermore, U0126 treatment inhibits DKK1-increased cell proliferation in 786-O cells. Our results reveal that DKK1 mediates A1CF to activate ERK in promotion renal carcinoma cell proliferation and colony formation. For the important function of ERK signaling pathway in tumor metastasis and key position of DKK1 in Wnt signaling pathway, we associate RNA editing protein-A1CF with multiple cellular processes and signaling pathways through DKK1, and the key node of A1CF-DKK1-MEK/ERK axis is a potential targeting site for RCC therapy.

Relationship between Gout and Diabetes Mellitus after Acute Pancreatitis: A Nationwide Cohort Study

OBJECTIVE

After acute pancreatitis, individuals often have low-grade inflammation, and subsequently develop metabolic sequelae such as post-pancreatitis diabetes mellitus (PPDM). Although numerous studies have investigated the relationship between gout and type 2 diabetes, little is known about the relationship between gout and PPDM. The aim was to investigate the associations between gout and PPDM.

METHODS

Using nationwide pharmaceutical dispensing data linked to hospital discharge data in New Zealand, gout and PPDM were identified among individuals after first episode of acute pancreatitis between January 1, 2007, and December 31, 2015. Multivariable Cox regression analyses were conducted, adjusting for age, sex, ethnicity, social deprivation index, alcohol consumption, tobacco smoking, comorbidities, medications (glucocorticoids, statins, and estrogens), and characteristics of acute pancreatitis.

RESULTS

A total of 10,117 individuals were included in the analysis of risk for gout and 9471 in the analysis of risk for PPDM. PPDM was significantly associated with a higher risk of gout in the overall cohort (adjusted HR 1.88, 95% CI 1.15-3.06) and women (2.72, 95% CI 1.31-5.65), but not in men (1.42, 95% CI 0.73-2.78). Preexisting gout was significantly associated with a higher risk of PPDM in the overall cohort (adjusted HR 1.58, 95% CI 1.04-2.41) and women (2.66, 95% CI 1.29-5.49), but not in men (1.31, 95% CI 0.78-2.20).

CONCLUSION

The relationship between gout and PPDM is bidirectional in the post-pancreatitis setting. A history of gout is a risk factor of PPDM, particularly in women.

An update on the genetics of hyperuricaemia and gout

A central aspect of the pathogenesis of gout is elevated urate concentrations, which lead to the formation of monosodium urate crystals. The clinical features of gout result from an individual's immune response to these deposited crystals. Genome-wide association studies (GWAS) have confirmed the importance of urate excretion in the control of serum urate levels and the risk of gout and have identified the kidneys, the gut and the liver as sites of urate regulation. The genetic contribution to the progression from hyperuricaemia to gout remains relatively poorly understood, although genes encoding proteins that are involved in the NLRP3 (NOD-, LRR- and pyrin domain-containing 3) inflammasome pathway play a part. Genome-wide and targeted sequencing is beginning to identify uncommon population-specific variants that are associated with urate levels and gout. Mendelian randomization studies using urate-associated genetic variants as unconfounded surrogates for lifelong urate exposure have not supported claims that urate is causal for metabolic conditions that are comorbidities of hyperuricaemia and gout. Genetic studies have also identified genetic variants that predict responsiveness to therapies (for example, urate-lowering drugs) for treatment of hyperuricaemia. Future research should focus on large GWAS (that include asymptomatic hyperuricaemic individuals) and on increasing the use of whole-genome sequencing data to identify uncommon genetic variants with increased penetrance that might provide opportunities for clinical translation.

Mediation analysis to understand genetic relationships between habitual coffee intake and gout

Background

Increased coffee intake is associated with reduced serum urate concentrations and lower risk of gout. Specific alleles of the GCKR, ABCG2, MLXIPL, and CYP1A2 genes have been associated with both reduced coffee intake and increased serum urate in separate genome-wide association studies (GWAS). The aim of this study was to determine whether these single nucleotide polymorphisms (SNPs) influence the risk of gout through their effects on coffee consumption.

Methods

This research was conducted using the UK Biobank Resource. Data were available for 130,966 European participants aged 40–69 years. Gout status and coffee intake were tested for association with four urate-associated SNPs: GCKR (rs1260326), ABCG2 (rs2231142), MLXIPL (rs1178977), and CYP1A2 (rs2472297). Multiple regression and path analysis were used to examine whether coffee consumption mediated the effect of the SNPs on gout risk.

Results

Coffee consumption was inversely associated with gout (multivariate adjusted odds ratio (95% confidence interval (CI)) for any coffee consumption 0.75 (0.67–0.84, P = 9 × 10⁻⁷)). There was also evidence of a dose-effect with multivariate adjusted odds ratio (95% CI) per cup consumed per day of 0.85 (0.82–0.87, P = 9 × 10⁻³²). The urate-increasing GCKR, ABCG2, MLXIPL, and CYP1A2 alleles were associated with reduced daily coffee consumption, with the strongest associations for CYP1A2 (beta −0.30, P = 8 × 10⁻⁴⁰), and MLXIPL (beta −0.17, P = 3 × 10⁻⁸), and weaker associations for GCKR (beta −0.07, P = 3 × 10⁻¹⁰) and ABCG2 (beta −0.09, P = 2 × 10⁻⁹). The urate-increasing GCKR and ABCG2 alleles were associated with gout (multivariate adjusted p < 5 × 10⁻⁸ for both), but the urate-increasing MLXIPL and CYP1A2 alleles were not. In mediation analysis, the direct effects of GCKR and ABCG2 accounted for most of the total effect on gout risk, with much smaller indirect effects mediated by coffee consumption.

Conclusion

Coffee consumption is inversely associated with risk of gout. Although alleles at several SNPs associate with both lower coffee consumption and higher risk of gout, these SNPs largely influence gout risk directly, rather than indirectly through effects on coffee consumption.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1629-5) contains supplementary material, which is available to authorized users.