In recent years, there has been increasing evidence that gut microbiota is associated with the onset and exacerbation of various diseases, such as gastrointestinal cancer. For instance, it is well ...known that local inflammation of the intestinal tract in colorectal cancer that is caused by the increased number of
, due to changes in the intestinal bacterial flora, is involved in carcinogenesis. In contrast, gut bacteria or their products, pathogen-associated molecular patterns, not only cause intestinal inflammation but also invade the bloodstream through dysbiosis and gut barrier dysfunction, thereby leading to systemic inflammation, namely bacterial translocation. The involvement of bacterial translocation in the carcinogenesis of gastrointestinal cancers and their prognosis is increasingly being recognized. The Toll-like receptor signaling pathways plays an important role in the carcinogenesis of such cancers. In addition, bacterial translocation influences the treatment of cancers such as surgery and chemotherapy. In this review, we outline the concept of bacterial translocation, summarize the current knowledge on the relationship between gut bacteria and gastrointestinal cancer, and provide future perspectives of this field.
Abstract
Objectives
Up to 0.3% of Japanese have hypouricaemia. Most cases appear to result from a hereditary disease, renal hypouricaemia (RHUC), which causes exercise-induced acute kidney injury and ...urolithiasis. However, to what extent RHUC accounts for hypouricaemia is not known. We therefore investigated its frequency and evaluated its risks by genotyping a general Japanese population.
Methods
A cohort of 4993 Japanese was examined by genotyping the non-functional variants R90H (rs121907896) and W258X (rs121907892) of URAT1/SLC22A12, the two most common causative variants of RHUC in Japanese.
Results
Participants’ fractional excretion of uric acid and risk allele frequencies markedly increased at lower serum uric acid (SUA) levels. Ten participants (0.200%) had an SUA level ≤2.0 mg/dl and nine had R90H or W258X and were likely to have RHUC. Logistic regression analysis revealed these URAT1 variants to be significantly and independently associated with the risk of hypouricaemia and mild hypouricaemia (SUA ≤3.0 mg/dl) as well as sex, age and BMI, but these URAT1 variants were the only risks in the hypouricaemia population (SUA ≤2.0 mg/dl). W258X was only a risk in males with SUA ≤3.0 mg/dl.
Conclusion
Our study accurately reveals the prevalence of RHUC and provides genetic evidence for its definition (SUA ≤2.0 mg/dl). We also show that individuals with SUA ≤3.0 mg/dl, especially males, are prone to RHUC. Our findings will help to promote a better epidemiological understanding of RHUC as well as more accurate diagnosis, especially in males with mild hypouricaemia.
Gout, caused by chronic elevation of serum uric acid levels, is the commonest form of inflammatory arthritis. The causative effect of common and rare variants of ATP-binding cassette transporter G2 ...(ABCG2/BCRP) on gout risk has been studied, but little attention has been paid to the effect of common (rs121907892, p.W258X) and rare variants of urate transporter 1 (URAT1/SLC22A12) on gout, despite dysfunctional variants of URAT1 having been identified as pathophysiological causes of renal hypouricaemia.
To address this important but overlooked issue, we investigated the effects of these URAT1 variants on gout susceptibility, using targeted exon sequencing on 480 clinically defined gout cases and 480 controls of Japanese males in combination with a series of functional analyses of newly identified URAT1 variants.
Our results show that both common and rare dysfunctional variants of URAT1 markedly decrease the risk of gout (OR 0.0338, reciprocal OR 29.6, P = 7.66 × 10-8). Interestingly, we also found that the URAT1-related protective effect on gout eclipsed the ABCG2-related causative effect (OR 2.30-3.32). Our findings reveal only one dysfunctional variant of URAT1 to have a substantial anti-gout effect, even in the presence of causative variants of ABCG2, a 'gout gene'.
Our findings provide a better understanding of gout/hyperuricaemia and its aetiology that is highly relevant to personalized health care. The substantial anti-gout effect of common and rare variants of URAT1 identified in the present study support the genetic concept of a 'Common Disease, Multiple Common and Rare Variant' model.
Measurement of event-related potentials (ERPs) in simulated and real environments is advantageous for understanding cognition and behavior during practice of goal-directed activities. Recently, ...instead of using task-irrelevant "probe stimuli" to elicit ERPs, extraction of ERPs directly from events that occur in simulated and real environments has drawn increased attention. Among the previous ERP studies using immersive virtual reality, only a few cases elicited ERPs from task-related events in dynamic task settings. Furthermore, as far as we surveyed, there were no studies that examined the source of ERPs or correlation between ERPs and behavioral performance in 360-degree immersive virtual reality using head-mounted display. In this study, EEG signals were recorded from 16 participants while they were playing the first-person shooter game with immersive virtual reality environment. Error related negativity (ERN) and correct-(response)-related negativity (CRN) elicited by shooting-related events were successfully extracted. We found the ERN amplitudes to be correlated with the individual shooting performance. Interestingly, the main source of the ERN was the rostral anterior cingulate cortex (ACC), which is different from previous studies where the signal source was often estimated to be the more caudal part of ACC. The obtained results are expected to contribute to the evaluation of cognitive functions and behavioral performance by ERPs in a simulated environment.
Objective
Serum uric acid (SUA) levels in humans are mainly regulated by urate transporters. Recent genome‐wide association studies suggested that common variants of the human sodium‐dependent ...phosphate cotransporter type 1 gene (NPT1/SLC17A1) influence SUA. NPT1 has been reported to mediate urate transport, but its physiologic role in regulating SUA in humans remains unclear. Furthermore, the findings of replication studies of the relationship between NPT1 variants and gout have been inconsistent. The aims of this study were to investigate the effect of NPT1 on gout and to determine its physiologic role.
Methods
Five hundred forty‐five male Japanese patients with gout and 1,115 male Japanese control subjects were genotyped for rs1165196 (I269T), a common missense variant in NPT1. Analyses of the association between rs1165196 and gout were then conducted, focusing especially on renal underexcretion (RUE) gout. Immunohistochemical analysis and functional analysis using Xenopus oocytes were also performed.
Results
Single‐nucleotide polymorphism rs1165196 significantly decreased the risk of RUE gout (odds ratio 0.73, P = 0.031) but did not confer a risk for all gout (P = 0.123). The immunohistochemical analysis revealed that human NPT1 is localized to the apical membrane of the renal proximal tubule. The functional analysis using Xenopus oocyte expression systems showed that rs1165196 increases NPT1‐mediated urate export.
Conclusion
This study showed that NPT1 is a urate exporter located in the renal proximal tubule in humans, and that its common gain‐of‐function variant, rs1165196, causes RUE gout, a major subtype of gout. These findings enable us to deepen our understanding of the physiologic role of NPT1 as a renal urate exporter as well as its pathophysiologic role in gout.
Renal hypouricemia (RHUC) is a disease caused by dysfunction of renal urate reabsorption transporters; however, diagnostic guidance and guidelines for RHUC have been lacking, partly due to the low ...evidence level of studies on RHUC. This review describes a world-first clinical practice guideline (CPG) and its first version in English for this condition. It was developed following the “MINDS Manual for Guideline Development” methodology, which prioritizes evidence-based medicine. It was published in Japanese in 2017 and later translated into English. The primary goal of this CPG is to clarify the criteria for diagnosing RHUC; another aim is to work towards a consensus on clinical decision-making. One of the CPG’s unique points is that it contains textbook descriptions at the expert consensus level, in addition to two clinical questions and recommendations derived from a systematic review of the literature. The guidance shown in this CPG makes it easy to diagnose RHUC from simple blood and urine tests. This CPG contains almost all of the clinical foci of RHUC: epidemiology, pathophysiology, diagnostic guidance, clinical examinations, differential diagnosis, and complications, including exercise-induced acute kidney injury and urolithiasis. A CPG summary as well as a clinical algorithm to assist healthcare providers with a quick reference and notes from an athlete for both physicians and patients are included. We hope that this CPG will help healthcare providers and patients to make clinical decisions, and that it will promote further research on RHUC.
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