Publications by authors named "Tsuneo Takenaka"

Klotho deficiency is prevalent in various chronic kidney diseases. Although klotho is known to bind transforming growth factor β (TGFβ) receptor 1 to antagonize renal fibrosis, TGFβ also maintains regulatory T cells with inducing forkhead box protein P3 (FOXP3). Female New Zealand Black/White F (NZBWF1) mice were divided into two groups (n = 10 for each): one group was treated with daily subcutaneous injection of klotho protein (30 μg/kg/day) for 8 weeks, and the other only received vehicle.

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Article Synopsis
  • * The study involved three groups of rats, with one group receiving klotho supplementation, leading to significant reductions in harmful substances like FGF23 and collagen levels associated with kidney fibrosis.
  • * Overall, the findings suggest that klotho supplementation may enhance kidney health by modulating various biological processes and improving kidney function in cases of renal damage.
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Purposes: Central blood pressure is a stronger predictor of cardiovascular prognosis rather than brachial blood pressure. The reflection wave reaches the abdominal aorta sooner than ascending aorta. Thus, the contribution of central pulse pressure (cPP) to renal events may differ from that of cardiovascular events.

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Bardoxolone methyl [methyl-2-cyano-3, 12-dioxooleana-1, 9(11)dien-28-oate (CDDO-Me)], an activator of the nuclear factor erythroid-derived 2-related factor2 pathway, is a potential therapeutic candidate for the treatment of kidney diseases. However, its effect against cellular senescence remains unclear. This study aimed to investigate whether CDDO-Me protects cells against cisplatin-induced cellular senescence using an in vitro model.

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Article Synopsis
  • Klotho is a protein that interacts with key receptors involved in kidney function and is decreased in chronic kidney disease, leading to complications like hypertension and albuminuria.
  • A study was conducted on HIGA mice, where they received daily injections of klotho to assess its effects on kidney health over two months.
  • The results showed that klotho supplementation lowered blood pressure and protein levels in urine while enhancing beneficial kidney proteins, suggesting it helps protect kidney function by suppressing harmful signals.
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Flaxseed oil contains lignans, which exhibit anti-inflammatory and antiatherogenic activities. A 70-year-old male patient presented to our office due to hyperlipidaemia and started to take a tablespoon of flaxseed oil daily. Three months later, he reported left breast swelling and pain.

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Article Synopsis
  • * A male patient with chronic kidney disease and a history of hepatitis experienced severe hyponatremia, or low sodium levels, after taking lubiprostone for constipation.
  • * The patient's symptoms included confusion and dehydration, but he recovered after treatment for his electrolyte imbalance, highlighting potential risks associated with these medications.
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Klotho interacts with various membrane proteins such as receptors for transforming growth factor-β (TGF-β) and insulin-like growth factor (IGF). Renal expression of klotho is diminished in polycystic kidney disease (PKD). In the present study, the effects of klotho supplementation on PKD were assessed.

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This simulation study attempted to infer the systolic blood pressure (SBP) levels at which subjects with hypertension, health nurses, and primary physicians should switch their preference of their treatment policies from lifestyle modifications to antihypertensive medications in virtual Japanese sample populations. We assumed that SBP levels were normally distributed and that the incidence rate of cardiovascular disease (IR, events/year) increased exponentially according to SBP. The total IR was calculated by the definite integral for the product of the distribution of SBP multiplied by IR at each SBP level.

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Renal expression of klotho is reduced in hypertension. Experiments were performed to examine whether exogenous klotho protein supplementation ameliorates pressure natriuresis in early phase of hypertension, using stroke-prone spontaneously hypertensive rats (sp-SHR). The interactions between klotho protein and renal renin-Ang (angiotensin) system were examined with immunoprecipitation and cell culture methods.

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Aims: Klotho interacts with various membrane proteins, such as receptors for transforming growth factor (TGF)-β and insulin-like growth factor (IGF), to alter their function. Renal expression of klotho is diminished in diabetes. The present study examined whether exogenous klotho protein supplementation ameliorates kidney injury and renin-angiotensin system (RAS) in db/db mice.

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It is not established whether central blood pressure (BP) evaluated by a radial pulse wave analysis is useful to predict cardiovascular prognoses. We tested the hypothesis that central BP predicts future cardiovascular events in treated hypertensive subjects. We conducted a multicenter, observational cohort study of 3566 hypertensives being treated with antihypertensive medications at 27 institutions in Japan.

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The progression of chronic kidney disease (CKD) inverts the arterial stiffness gradient. However, central hemodynamic pressure profiles in CKD have not been fully examined. A cross-sectional study was performed to assess the relationship between the CKD stage and central hemodynamic processes.

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Megalin, an endocytic receptor expressed in proximal tubule cells, plays a critical role in renal tubular protein reabsorption and is associated with the albuminuria observed in diabetic nephropathy. We have previously reported increased oxidant production in the renal cortex during the normoalbuminuric stage of diabetes mellitus (DM); however, the relationship between oxidative stress and renal megalin expression during the normoalbuminuric stage of DM remains unclear. In the present study, we evaluated whether oxidative stress affects megalin expression in the normoalbuminuric stage of DM in a streptozotocin-induced diabetic rat model and in immortalized human proximal tubular cells (HK-2).

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Aims: To assess the effects of sodium-glucose co-transporter type 2 inhibitors on central blood pressure, an important determinant of cardiovascular events.

Methods: Canagliflozin, Empagliflozin or Luseogliflozin was given for 102 type 2 diabetic patients with hypertension and nephropathy. Central blood pressure was evaluated by radial tonometry.

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Background: The effects of sodium-glucose co-transporter type 2 inhibitors on home blood pressure were examined in type 2 diabetes with nephropathy.

Methods: The patients with diabetic nephropathy were screened from medical records in our hospitals. Among them, 52 patients who measured home blood pressure and started to take sodium-glucose co-transporter type 2 inhibitors were selected.

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Background: Kidney resistive index (RI) correlates with tubulointerstitial changes and predicts renal prognosis. Most patients with chronic kidney diseases (CKDs) manifest high blood pressure and atherosclerotic cardiovascular diseases. In addition, various atherosclerotic indexes relate to variations in blood pressure.

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Backgrounds: Klotho protein interacts with the transforming growth factor β (TGF-β) receptor and Wnt, which contribute to the progression of renal disease, inhibiting their signals. Renal and circulating klotho levels are diminished in chronic kidney disease.

Methods: Experiments were performed to assess whether supplementation of klotho protein could have protective effects on the kidney.

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Objective It is difficult to compare directly the practical effects of lifestyle modifications and antihypertensive medications on reducing cardiovascular disease (CVD). The purpose of this study was to compare the hypothetical potential of lifestyle modifications with that of antihypertensive medications in reducing CVD in an aging society using a success rate-oriented simulation. Methods We constructed a simulation model for virtual Japanese subpopulations according to sex and age at 10-year intervals from 40 years of age as an example of an aging society.

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In this review, we focused on the relationship between central blood pressure and chronic kidney diseases (CKD). Wave reflection is a major mechanism that determines central blood pressure in patients with CKD. Recent medical technology advances have enabled non-invasive central blood pressure measurements.

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Although fibroblast growth factor (FGF) 23 was recently identified as a phosphatonin that influences vitamin D metabolism, the underlying signaling mechanisms remain unclear. FGF23 elevates the renal levels of membrane-associated klotho as well as soluble klotho. Klotho is expressed on distal tubules.

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Hyperphosphatemia accelerates the progression of chronic kidney diseases. In the present study, the effects of ronacaleret, a calcilytic agent, on renal injury were assessed in the following four groups of rats: 5/6-nephrectomized Wistar rats as a control (C group), rats treated with ronacaleret (3 mg·kg(-1)·day(-1); R group), rats treated with calcitriol (30 ng·kg(-1)·day(-1); V group), and rats treated with both ronacaleret and calcitriol (R + V group). Three months later, rats were euthanized under anesthesia, and the remnant kidneys were harvested for analysis.

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