Published papers

© 2019, The Author(s). The Japanese hypertension guidelines report that essential hypertension is detected in 1–3% of upper elementary and high school students during blood pressure (BP) screenings. Hypertension in these age groups is an emerging public health concern mainly attributed to the rising rate of pediatric obesity. Considering the existence of BP tracking phenomenon, early preventive education and instruction are necessary, especially for male students with moderately elevated BP showing a tendency toward obesity, despite the low prevalence of hypertension in high school students. Students with a positive family history of hypertension and those born with low birth weight need the same measures. Lifestyle habits, such as increased alcohol intake, dramatically change once students begin university; thus, early education and instruction regarding the factors influencing BP are necessary. In particular, for male students with higher BP during high school, caution regarding increased body weight is required irrespective of their level of obesity. Young adults aged <40 years should be educated about the association between body weight and hypertension. Particular caution surrounding lifestyle habits, including drinking and smoking, is warranted in male hypertensive subjects because hypertension at a young age is strongly associated with obesity. BP monitoring and the management of obesity should be considered efficient approaches to the detection and treatment of hypertension. For the lifetime prevention of hypertension, it is essential to be aware of one’s health status and learn about healthy lifestyles beginning in childhood. BP measurement may be an appropriate means to achieve this goal.

© 2019, Japanese Society of Nephrology. Background: Low birth weight (LBW) is a risk factor for chronic kidney disease (CKD) in later life and is becoming increasingly common in developed countries, including Japan. Furthermore, a serial decrease in birth weight has been associated with an increasing prevalence of CKD stage 2 in male Japanese adolescents. Sex-specific differences affect CKD susceptibility, and the association between birth weight and CKD in women, has not been elucidated. In this study, we investigated the sex-specific effect of LBW on renal function. Methods: Annual cross-sectional data of 2417 Japanese adolescents (males 1736; females 681), aged 15–16 years, were evaluated over 8 years (2007–2014). Results: Over the study period, mean birth weights decreased significantly in males (p < 0.01) and females (p < 0.05). Furthermore, both sexes showed significant decrease in estimated glomerular filtration rates corresponding to the birth weight reduction. The prevalence of CKD stage 2 also increased in males (from 26.0 to 32.4%, p < 0.01) and females (from 6.3 to 18.5%, p < 0.05). The incidence of CKD stage 2 was significantly related to history of LBW (males: odds ratio 1.73; 95% confidence interval 1.06–2.80; p < 0.05; females: odds ratio 3.29; 95% confidence interval 1.25–8.02; p < 0.05). Conclusions: Our data revealed that renal function and birth weight have decreased over time, in healthy Japanese adolescents. In view of the recent declining trend demonstrated by birth weight in Japan, we speculate that the prevalence of CKD might increase in the future.

The “preconditioning effect” in AKI is a phenomenon in which an episode of ischemia-reperfusion results in tolerance to subsequent ischemia-reperfusion injury. However, its relationship between DNA damage repair has not been elucidated. Here, we show the role of KAT5 in the preconditioning effect. Preconditioning attenuated DNA damage in proximal tubular cells with elevated KAT5 expression. Ischemia-reperfusion (IR) injuries were exacerbated, and preconditioning effect vanished in proximal tubular-cell-specific KAT5 knockout mice. Investigation of tubuloglomerular feedback (TGF) by MALDI-IMS and urinary adenosine revealed that preconditioning caused attenuated TGF at least in part via KAT5. In addition, K-Cl cotransporter 3 (KCC3) expression decreased in damaged proximal tubular cells, which may be involved in accelerated TGF following IR. Furthermore, KAT5 induced KCC3 expression by maintaining chromatin accessibility and binding to the KCC3 promoter. These results suggest a novel mechanism of the preconditioning effect mediated by the promotion of DNA repair and attenuation of TGF through KAT5.

Unplanned dialysis initiation is associated with poor outcomes. It is controversial whether patients with advanced chronic kidney disease (CKD) should receive renin-angiotensin system (RAS) inhibitor therapy. The aim of this study was to evaluate the effect of RAS inhibitor therapy in patients with advanced CKD on the incidence of unplanned dialysis initiation. This single-center, retrospective study included patients who started maintenance dialysis at our hospital between April 2014 and March 2021. Patients who initiated dialysis within 6 months of nephrology referral or after kidney transplant were excluded. Among 334 patients (aged 70.0 [59.0–79.0] years; 28.4% women), 186 (55.7%) and 148 (44.3%) had planned and unplanned dialysis initiation, respectively. Multivariate logistic regression analysis revealed that the use of RAS inhibitors was significantly associated with a lower incidence of unplanned dialysis initiation (odds ratio [OR], 0.36; P < 0.01). Female sex (OR, 0.41; P < 0.05), use of potassium binders (OR, 0.28; P < 0.001), earlier referral to nephrology (OR, 0.39; P < 0.01), and earlier discussion of renal replacement therapy (OR, 0.33; P < 0.001) were also significantly associated with a lower incidence, whereas older age (OR, 1.28; P < 0.05), higher Charlson Comorbidity Index (OR, 1.24; P < 0.05), and faster decline in kidney function (OR, 1.29; P < 0.01) were associated with a higher risk of unplanned dialysis initiation. RAS inhibitor therapy in patients with advanced CKD is associated with a lower risk of unplanned dialysis initiation.

A 46-year-old woman developed takotsubo cardiomyopathy and nephrotic syndrome. The first kidney biopsy suggested non-immune-complex-mediated membranoproliferative glomerulonephritis (MPGN), and she was diagnosed with glomerular endothelial injury associated with takotsubo cardiomyopathy. A second biopsy was performed two years later because of persistent proteinuria despite renin-angiotensin system inhibition. This biopsy indicated non-immune-complex-mediated MPGN, but a mesangial and subendothelial substance of a higher electron density than that in the first biopsy was detected, suggesting the possibility of glomerular disease with non-immune deposits rather than endothelial injury. Finally, she was diagnosed with fibronectin nephropathy. Although rare, fibronectin glomerulopathy should be considered in non-immune-complex-mediated MPGN.

© 2020, The Author(s). Accumulation of DNA double-strand breaks (DSBs) is linked to aging and age-related diseases. We recently reported the possible association of DNA DSBs with altered DNA methylation in murine models of kidney disease. However, DSBs and DNA methylation in human kidneys was not adequately investigated. This study was a cross-sectional observational study to evaluate the glomerular DNA DSB marker γH2AX and phosphorylated Ataxia Telangiectasia Mutated (pATM), and the DNA methylation marker 5-methyl cytosine (5mC) by immunostaining, and investigated the association with pathological features and clinical parameters in 29 patients with IgA nephropathy. To evaluate podocyte DSBs, quantitative long-distance PCR of the nephrin gene using laser-microdissected glomerular samples and immunofluorescent double-staining with WT1 and γH2AX were performed. Glomerular γH2AX level was associated with glomerular DNA methylation level in IgA nephropathy. Podocytopathic features were associated with increased number of WT1(+)γH2AX(+) cells and reduced amount of PCR product of the nephrin gene, which indicate podocyte DNA DSBs. Glomerular γH2AX and 5mC levels were significantly associated with the slope of eGFR decline over one year in IgA nephropathy patients using multiple regression analysis adjusted for age, baseline eGFR, amount of proteinuria at biopsy and immunosuppressive therapy after biopsy. Glomerular γH2AX level was associated with DNA methylation level, both of which may be a good predictor of renal outcome in IgA nephropathy.

© 2021, The Author(s), under exclusive licence to The Japanese Society of Hypertension. Early intervention to manage high blood pressure (BP) in young adulthood is a promising approach for the prevention of future cardiovascular diseases. We aimed to examine the ability of childhood health information to predict the incidence of young adults with high BP. This cohort study included baseline clinical data of Japanese individuals aged 12–13 years. A total of 1129 participants were followed up for an average of 8.6 years. We examined the association of childhood variables consisting of body weight, body mass index, systolic BP, white blood cell count, red blood cell count, hemoglobin, hematocrit, platelet count, uric acid, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol with the development of high BP defined as ≥120/80 mmHg at 18–22 years old. At follow-up, the prevalence of high BP was 42.2% in men and 7.7% in women. Young men with high BP had childhood baseline characteristics that included higher body weight, body mass index, systolic BP, red blood cell count, hemoglobin, hematocrit, and uric acid than normotensive men. Young women with high BP had higher body weight, systolic BP, and uric acid at baseline. Multivariable logistic regression analysis revealed that a model including body weight, systolic BP, hematocrit, and uric acid had the highest predictive power (AUC 0.65 [95% CI, 0.62–0.69]) for men, and a model including body weight, systolic BP, and uric acid had the highest predictive power (AUC 0.70 [95% CI, 0.58–0.81]) for women. Comprehensive childhood health information contributes to the prediction of high BP in young adults.

Hypertension is the most common non-communicable disease among adults and is the most important modifiable risk factor for premature cardiovascular disease. The increasing worldwide burden of hypertension is a major global health issue. Early prevention with lifestyle modification or pharmaceutical treatment reduces the incidence of hypertension and the risk of subsequent cardiovascular disease. Therefore, identification of young persons at risk for hypertension has the obvious benefit of providing a chance for early intervention. Previous studies have demonstrated the positive association of elevated childhood blood pressure with hypertension in adulthood. Accumulated evidence also indicates the possibility that elevated pediatric blood pressure is associated with increased risk of future cardiovascular disease. In this article, we review the tracking of blood pressure from childhood to adulthood and emphasize the importance of pediatric blood pressure monitoring and control for predicting and preventing adult hypertension and cardiovascular disease.

© Springer Nature Singapore Pte Ltd. 2019. Obesity prevalence continues to increase in both adults and children worldwide and greatly contributes to increased morbidity and mortality. Although there are some anti-obesity drugs globally available for clinical use, their inadequate effectiveness coupled with safety concerns sometimes discourage the widespread use of anti-obesity medication. Because of its prolonged therapeutic effect and low frequency of administration, a therapeutic vaccine may be an attractive strategy for the prevention and treatment of obesity. Over the last two decades, several attempts have been made to develop vaccines for the control of obesity. Animal studies have shown that vaccines targeting ghrelin, glucose-dependent insulinotropic polypeptide, adipocytes, somatostatin, and adenovirus 36 successfully led to a reduction in weight gain without serious adverse effects. This chapter provides an overview of recent progress toward a therapeutic vaccine against obesity.

© 2020 Elsevier Inc. All rights reserved. Plant-based vaccines (PbVs), developed with novel plant genetic engineering technologies, offer a new strategy for the production, storage, and delivery of vaccines. PbVs can overcome practical and economic concerns surrounding injectable vaccines, including the need for medical staff to perform the injections and the costs of production and refrigeration. The development of unrefrigerated, needle-free vaccines will support the prevention of infectious diseases in developing countries. Although no PbV has yet been licensed for human clinical use, some are now in clinical trials. Antigen-encoding genes introduced into potatoes, lettuce, spinach, corn, tobacco, soybeans, and rice can produce vaccines against mucosal and systemic infectious diseases, including enterotoxigenic Escherichia coli, Vibrio cholerae, norovirus, influenza virus, hepatitis B virus, and rabies virus. This chapter introduces the plant genetic engineering technologies used and clinical trials of PbVs.