Search

Purpose: Olmesartan and azilsartan decrease blood pressure more effectively than other angiotensin receptor blockers (ARBs). ARBs additionally decrease the urinary albumin to creatinine ratio (UACR), a urinary albumin marker, and urinary angiotensinogen (u-AGT), an intrarenal renin-angiotensin system activity marker. We examined the effects of these ARBs on blood pressure, UACR, and u-AGT in patients with uncontrolled hypertension. Methods: Patients with uncontrolled hypertension treated with conventional ARBs, excluding olmesartan and azilsartan, for over 8 weeks were enrolled. We randomly switched patients from their prior ARBs to either olmesartan or azilsartan, and followed them for 24 weeks. Results: Systolic blood pressure (SBP), diastolic blood pressure (DBP), and central systolic blood pressure (cSBP) significantly decreased at 24 weeks. UACR and u-AGT also decreased at 24 weeks in both groups. There were no significant differences in SBP, DBP, cSBP, UACR, or u-AGT between the groups. Therefore, we combined both groups for further analyses. After combining, SBP (160.5 plusmn 16.4 to 139.6 plusmn 15.6 mm Hg, P lt 0.0001), DBP (88.4 plusmn 13.7 to 80.7 plusmn 13.2 mm Hg, P = 0.008), cSBP (167.4 plusmn 20.8 to 146.6 plusmn 24.6 mm Hg, P lt 0.0001), UACR (13.8 to 9.0 mg/g Cre, P = 0.0096), and u-AGT (4.13 to 2.32 microg/g Cre, P = 0.0074) significantly decreased at 24 weeks. Patients with microalbuminuria (UACR ge 30 mg/g Cre) had significantly greater DeltaUACR (-39.4 vs 0.27, P = 0.0024) and Deltau-AGT (-11.9 vs -0.61, P = 0.0235) than patients without microalbuminuria. The changes in u-AGT were significantly associated with changes in UACR (r = 0.411, P = 0.046) however, there was no significant relationship between the changes in u-AGT and those in SBP or DBP. Conclusion: Olmesartan and azilsartan decreased blood pressure, UACR, and u-AGT more than the other ARBs, and exerted depressor and renoprotective effects.

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. Methods We investigated the effects of klotho supplementation on diabetic kidney injury and RAS. Recombinant human klotho protein (10 μg/kg/d) was administered to db/db mice daily. Results Klotho protein supplementation reduced kidney weight, systolic blood pressure (SBP), albuminuria, glomerular filtration rate, and 8-epi-prostaglandin F2α excretion without affecting body weight. Although klotho supplementation did not alter glycated albumin, it reduced renal angiotensin II levels associated with reduced renal expression of angiotensinogen. Klotho supplementation improved renal expression of superoxide dismutase (SOD), and endogenous renal expression of klotho. Klotho supplementation reduced the levels of hypoxia-inducible factor, phosphorylated Akt, and phosphorylated mTOR and decreased the renal expression of TGF-β, tumour necrosis factor (TNF), and fibronectin. Conclusions These data indicate that klotho supplementation reduces blood pressure and albuminuria along with ameliorating renal RAS activation in db/db mice. Furthermore, these results suggest that klotho inhibits IGF signalling, induces SOD expression to reduce oxidative stress, and suppresses Akt-mTOR signalling to inhibit abnormal kidney growth. Collectively, the results suggest that klotho inhibits TGF-β and TNF signalling, resulting in a decline in renal fibrosis.

A non-invasive, ultrasonic-assisted mid-infrared Fourier spectroscopy method to determine blood glucose levels in mice is proposed, which can be installed into smartphones. This technique is shown to depend on the time when measurements are recorded.

To realize a noninvasive blood glucose sensor, we propose a method to generate reflection planes inside agar using ultrasonic standing waves. This method allows measurement of the glucose concentrations inside agar samples using mid-infrared spectroscopy.

We propose to monitor blood glucose concentrations using mid-infrared spectroscopy in an ultrasonic-assisted liquid cell that can be attached to a dialyzer. This method can measure the transmitted light through whole blood during dialysis.

We retrospectively assessed the clinical significance of the Prostate Imaging Reporting and Data System (PI-RADS), version 2, criteria based on biparametric magnetic resonance imaging (bp-MRI), together with the International Society of Urological Pathology (ISUP) grade, for predicting biochemical recurrence (BCR) after radical prostatectomy.The data from 126 patients who had undergone radical prostatectomy were retrospectively analyzed. The prognostic significance of the PI-RADS v2 score based on bp-MRI was assessed with other clinical factors, including the ISUP grade. We defined a positive PI-RADS and ISUP score as ≥ 4 and ≥ 3, respectively. Statistical analysis was performed using Cox proportional hazard models, logistic regression analysis, and the Kaplan-Meier method.The median age and median prostate-specific antigen level were 66 years and 7.96 ng/mL, respectively. The number of positive PI-RADS scores was 106 (84.1%) and the number of positive ISUP grade scores was 71 (56.3%). PI-RADS ≥ 4 (P = .0031) and ISUP ≥ 3 (P = .070) were the 2 independent prognostic factors predictive of BCR. A positive PI-RADS score was related to tumor volume (P = .014), and a positive ISUP score was related to prostate-specific antigen level (P = .043), extraprostatic extension (P = .029), and Gleason upgrading (P .0001). After stratifying patients into risk groups according to PI-RADS and ISUP positivity, the poor-risk group (PI-RADS and ISUP grade positive) showed significantly worse BCR-free survival compared with that of the favorable- and intermediate-risk groups (P .0001), with a median survival difference of 21 months.Biparametric PI-RADS v2 and ISUP grade criteria predicted for BCR after radical prostatectomy. PI-RADS v2 combined with the ISUP grade might be helpful in choosing the treatment modality of patients with localized prostate cancer.

The morning surge in blood pressure (BP) coincides with increased cardiovascular (CV) events. This strongly suggests that an altered circadian rhythm of BP plays a crucial role in the development of CV disease (CVD). A disrupted circadian rhythm of BP, such as the non-dipping type of hypertension (i.e., absence of nocturnal BP decline), is frequently observed in metabolic disorders and chronic kidney disease (CKD). The circadian timing system, controlled by the central clock in the suprachiasmatic nucleus of the hypothalamus and/or by peripheral clocks in the heart, vasculature, and kidneys, modulates the 24 h oscillation of BP. However, little information is available regarding the molecular and cellular mechanisms of an altered circadian timing system-mediated disrupted dipping pattern of BP in metabolic disorders and CKD that can lead to the development of CV events. A more thorough understanding of this pathogenesis could provide novel therapeutic strategies for the management of CVD. This short review will address our and others’ recent findings on the molecular mechanisms that may affect the dipping pattern of BP in metabolic dysfunction and kidney disease and its association with CV disorders.

Smart toilets could be used to monitor different components of urine in daily life for early detection of lifestyle-related diseases and prompt provision of treatment. For analysis of biological samples such as urine by midinfrared spectroscopy, thin-film samples like liquid cells are needed because of the strong absorption of midinfrared light by water. Conventional liquid cells or fixed cells are prepared based on the liquid membrane method and solution technique, but these are not quantitative and are difficult to set up and clean. We generated an ultrasonic standing wave reflection plane in a sample and produced an ultrasonic liquid cell. In this cell, the thickness of the optical path length was adjustable, as in the conventional method. The reflection plane could be generated at an arbitrary depth and internal reflected light could be detected by changing the frequency of the ultrasonic wave. We could generate refractive index boundaries using the density difference created by the ultrasonic standing wave. Creation of the reflection plane in the sample was confirmed by optical coherence tomography. Using the proposed method and midinfrared spectroscopy, we discriminated between normal urine samples spiked with glucose at different concentrations and obtained a high correlation coefficient.

Obesity, an important risk factor for metabolic syndrome (MetS) and cardiovascular disease, is often complicated by CKD, which further increases cardiovascular risk and causes ESRD. To elucidate the mechanism underlying this relationship, we investigated the role of the endocytic receptor megalin in proximal tubule epithelial cells (PTECs). We studied a high-fat diet (HFD)-induced obesity/MetS model using kidney-specific mosaic megalin knockout (KO) mice. Compared with control littermates fed a normal-fat diet, control littermates fed an HFD for 12 weeks showed autolysosomal dysfunction with autophagy impairment and increased expression of hypertrophy, lipid peroxidation, and senescence markers in PTECs of the S2 segment, peritubular capillary rarefaction with localized interstitial fibrosis, and glomerular hypertrophy with mesangial expansion. These were ameliorated in HFD-fed megalin KO mice, even though these mice had the same levels of obesity, dyslipidemia, and hyperglycemia as HFD-fed control mice. Intravital renal imaging of HFD-fed wild-type mice also demonstrated the accumulation of autofluorescent lipofuscin-like substances in PTECs of the S2 segment, accompanied by focal narrowing of tubular lumens and peritubular capillaries. In cultured PTECs, fatty acid-rich albumin induced the increased expression of genes encoding PDGF-B and monocyte chemoattractant protein-1 via megalin, with large (auto)lysosome formation, compared with fatty acid-depleted albumin. Collectively, the megalin-mediated endocytic handling of glomerular-filtered (lipo)toxic substances appears to be involved primarily in hypertrophic and senescent PTEC injury with autophagy impairment, causing peritubular capillary damage and retrograde glomerular alterations in HFD-induced kidney disease. Megalin could be a therapeutic target for obesity/MetS-related CKD, independently of weight, dyslipidemia, and hyperglycemia modification.

Angiotensin II (Ang II) and aldosterone contribute to hypertension, oxidative stress and cardiovascular damage, but the contributions of aldosterone during Ang II-dependent hypertension are not well defined because of the difficulty to assess each independently. To test the hypothesis that during Ang II infusion, oxidative and nitrosative damage is mediated through both the mineralocorticoid receptor (MR) and angiotensin type 1 receptor (AT1), five groups of Sprague-Dawley rats were studied: (i) control; (ii) Ang II infused (80ng/min×28days); (iii) Ang II+AT1 receptor blocker (ARB; 10mg losartan/kg per day×21days); (iv) Ang II+mineralocorticoid receptor (MR) antagonist (Epl; 100mg eplerenone/day×21days); and (v) Ang II+ARB+Epl (Combo;×21days). Both ARB and combination treatments completely alleviated the Ang II-induced hypertension, whereas eplerenone treatment only prolonged the onset of the hypertension. Eplerenone treatment exacerbated the Ang II-mediated increase in plasma and heart aldosterone 2.3- and 1.8-fold, respectively, while ARB treatment reduced both. Chronic MR blockade was sufficient to ameliorate the AT1-mediated increase in oxidative damage. All treatments normalized protein oxidation (nitrotyrosine) levels; however, only ARB and Combo treatments completely reduced lipid peroxidation (4-hydroxynonenal) to control levels. Collectively, these data suggest that receptor signalling, and not the elevated arterial blood pressure, is the principal culprit in the oxidative stress-associated cardiovascular damage in Ang II-dependent hypertension.

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. Albuminuria was lower in the R and V groups than in the C group ( P < 0.05). Creatinine clearance was elevated in the R and V groups compared with the C group ( P < 0.05). Serum Ca2+ and renal ANG II were higher in the R + V group than in the C group ( P < 0.05 for each), and serum phosphate was reduced in the R group compared with the C group ( P < 0.05). Fibroblast growth factor-23 was lower in the R group and higher in the V and R + V groups than in the C group. However, parathyroid hormone did not differ significantly among the four groups. Renal klotho expression was elevated in the R and V groups compared with the C group ( P < 0.05). The present data indicate that ronacaleret preserves klotho expression and renal function with reductions in serum phosphate and albuminuria in 5/6-nephrectomized rats. Our findings demonstrate that vitamin D prevents declines in klotho expression and renal function, suppressing albuminuria.

SUMMARY The detailed mechanisms determining the course of congestive heart failure (CHF) in hypertensive subjects with associated renal dysfunction remain unclear. In Ren-2 transgenic rats (TGR), a model of angiotensin II (ANG II)-dependent hypertension, CHF was induced by volume overload achieved by creation of the aorto-caval fistula (ACF). In these rats we investigated the putative pathophysiological contribution of epoxyeicosatrienoic acids (EETs) and compared it with the role of the renin-angiotensin system (RAS). We found that untreated ACF TGR exhibited marked intrarenal and myocardial deficiency of EETs and impairment of renal function. Chronic treatment of these rats with cis-4-[4-(3-adamantan-1yl-ureido)cyclohexyloxy]benzoic acid (c-AUCB, 3 mg/L in drinking water), an inhibitor of soluble epoxide hydrolase (sEH) which normally degrades EETs, increased intrarenal and myocardial EETs, markedly improved survival rate, and increased renal blood flow, glomerular filtration rate and fractional sodium excretion, without altering RAS activity. Chronic angiotensin-converting enzyme inhibition (ACEi) with trandolapril, (6 mg/L in drinking water) improved survival rate even more, and also inhibited the development of renal dysfunction; these beneficial actions were associated with significant suppression of the vasoconstrictor/sodium retaining axis and further activation of the vasodilatory/natriuretic axis of the systemic and intrarenal RAS, without modifying tissue availability of biologically active fatty acid epoxides. In conclusion, these findings strongly suggest that chronic sEH inhibition and chronic treatment with ACEi, each of them altering a different vasoactive system, delay or even prevent the onset of decompensation of CHF in ACF TGR, probably by preventing the development of renal dysfunction.

We previously reported that the functional deletion of p21, a cyclin-dependent kinase inhibitor, in mice attenuated renal cell senescence in streptozotocin (STZ)-induced type 1 diabetic mice. In the present study, we investigated the effect of iron chelation on renal cell senescence and inflammation in the type 1 diabetic kidney. STZ-treated mice showed increase in iron accumulation, tubular cell senescence and macrophage infiltration at week 28 in the kidney. Administering deferasirox, which removes only dietary iron, significantly attenuated iron accumulation in proximal tubules and the number of infiltrating F4/80-positive cells without effecting blood glucose, hematocrit or hemoglobin levels. In contrast however, deferasirox did not influence renal cell senescence. The lack of p21 decreased the renal tubular iron accumulation and did not change tubular cell senescence. Interestingly, the STZ-treated animals showed an increase in p16, another cyclin-dependent kinase inhibitor. The results suggest that type 1 diabetes increases renal tubular iron accumulation and macrophage infiltration through a p21-dependent mechanism, and that the chelation of dietary iron attenuates these responses.

The renal tissue renin-angiotensin system is activated in chronic kidney diseases. We previously demonstrated that intrarenal ANG II is synthesized primarily from liver-derived angiotensinogen filtered through the glomerulus and that podocyte injury increases the passage of angiotensinogen into the tubular lumen and generation of ANG II. In the present study, we tested the effect of cessation of glomerular filtration by ureteral obstruction on renal ANG II generation in kidneys with podocyte injury under two experimental conditions. Ureteral obstruction is known to activate the renin-angiotensin system in nonproteinuric kidneys. Transgenic mice expressing hCD25 in podocyte (NEP25) were injected with 1.25 or 10 ng/g body wt of LMB2, a hCD25-targeted immunotoxin, subjected to unilateral ureteral ligation on the following day, and euthanized 7 and 4 days later, respectively. In both experiments, compared with the kidney in untreated wild-type mice, renal angiotensinogen protein, as assessed by immunostaining and Western blot analysis, was increased in the contralateral unobstructed kidney. However, it was markedly decreased in the obstructed kidney. Whereas intrarenal ANG II content was increased in the contralateral kidney compared with the untreated kidney (248 ± 83 vs. 106 ± 21 and 298 ± 185 vs. 64.8 ± 20 fmol/g kidney, respectively), this increase was suppressed in the obstructed kidney (161 ± 75 and 113 ± 34 fmol/g kidney, respectively), a pattern opposite to what we expected in obstructed kidneys without podocyte injury. Thus, our study indicates that the major source of increased renal ANG II in podocyte injury is filtered angiotensinogen.

Background Post-transplantation de novo and recurrent immunoglobulin A (IgA) deposition (IgAD) in the allograft is commonly observed. However, the association between post-transplantation IgAD and reduced allograft function has not been determined. We therefore investigated the association between reduced allograft function and post-transplantation IgAD using serial allograft biopsies. Methods IgAD was retrospectively analyzed in 45 adults who underwent kidney transplantation for chronic glomerulonephritis, including IgA nephropathy, at Kagawa University Hospital. Allograft biopsy samples were obtained from per protocol biopsies obtained 1 and 3 years after transplantation, as well as from episode biopsies. Factors contributing to post-transplantation IgAD were assessed by calculating adjusted odds ratios (AORs) using logistic regression analysis. Results Of the 45 recipients, 18 had post-transplantation allograft IgAD. The estimated glomerular filtration rates (eGFR) 1, 2, and 3 years after transplantation were lower in the recipients with than without IgAD. Urinalysis was normal in 61% of recipients with IgAD. Reduced allograft function (eGFR 2 ) 1 year after transplantation was significantly associated with post-transplantation IgAD (AOR = 34.4 [95% CI = 2.35–502], P = .01). Conversely, blood concentrations of mycophenolic acid and latent IgAD from donor kidneys were not significantly associated with post-transplantation IgAD. Conclusion Reduced allograft function may be associated with post-transplantation IgAD in the allograft.

Basophils and mast cells play critical roles in host defense against pathogens and allergic disorders. However, the molecular mechanism by which these cells are generated is not completely understood. Here we demonstrate that interferon regulatory factor-8 (IRF8), a transcription factor essential for the development of several myeloid lineages, also regulates basophil and mast cell development. Irf8(-/-) mice displayed a severe reduction in basophil counts, which was accounted for by the absence of pre-basophil and mast cell progenitors (pre-BMPs). Although Irf8(-/-) mice retained peripheral tissue mast cells, remaining progenitors from Irf8(-/-) mice including granulocyte progenitors (GPs) were unable to efficiently generate either basophils or mast cells, indicating that IRF8 also contributes to the development of mast cells. IRF8 appeared to function at the GP stage, because IRF8 was expressed in GPs, but not in basophils, mast cells, and basophil/mast cell-restricted progenitor cells. Furthermore, we demonstrate that GATA2, a transcription factor known to promote basophil and mast cell differentiation, acts downstream of IRF8. These results shed light on the pathways and mechanism underlying the development of basophils and mast cells.

Although a large amount of research on Li ion transportation has been carried out with the aim of improving the properties of lithium ion batteries, there has been little detailed research on electron conduction. Hence, we have been focusing on improving the charge/discharge performance of lithium ion batteries by increasing the electron conductivity of the electrodes. The electron conductivity of crystalline tungsten trioxide (WO 3 ) was found to be increased by N 2 annealing owing to the generation of oxygen vacancies. It was clarified that increasing the conductivity of the electrodes can improve the performance of lithium ion batteries, particularly their charge/discharge speed and reversibility. Additionally, the best performance was observed in a sample subjected to high-temperature annealing at 700 °C in N 2 ambient, which decreased the resistivity of the WO 3 electrode by five orders of magnitude and simultaneously changed the monoclinic crystalline structure into a cubiclike structure into which Li ions are more easily intercalated. Therefore, to enhance the charge/discharge performance of lithium ion batteries, electron conduction should be a focus of research. Crystalline WO 3 was also demonstrated to be a promising material for electrodes since oxygen vacancy generation can be induced by a simple annealing treatment, improving the electron conduction and Li ion transportation.

We report a new approach for improving the recharging and discharging speed of lithium ion batteries based on understanding of the electron conduction mechanism of tungsten trioxide (WO 3 ) powder thin films fabricated from nanoparticles and used in lithium ion battery electrodes. Resistivity measurements are carried out after annealing in N 2 or 5% O 2 + 95% N 2 ambient. Annealing in N 2 ambient decreases the resistivity owing to the increased number of oxygen vacancies in the WO 3 thin film. Fitting results obtained from the resistivity are used to propose the simultaneous existence of two types of electron conduction mechanism, band conduction and nearest-neighbor hopping (NNH) conduction, contributing to electron conduction in WO 3 thin films.

( R )-Isovaline has potential applications in drug development, and therefore the development of an efficient method for the production of ( R )-isovaline is desired. Herein we have investigated the asymmetric hydrolysis of 2-ethyl-2-methyl-malonamide into ( S )-2-ethyl-2-methyl-malonamic acid, a useful synthetic intermediate in the production of ( R )-isovaline, using Cs AM, which is a recombinant amidase originally derived from Cupriavidus sp. KNK-J915. The produced ( S )-2-ethyl-2-methyl-malonamic acid (98.6% ee) could be easily converted into ( R )-isovaline by the Hofmann rearrangement. Starting from diethyl 2-methylmalonate, we obtained ( R )-isovaline (99.1% ee) in 58.6% yield over eight steps, including the Cs AM-catalyzed asymmetric hydrolysis of 2-ethyl-2-methyl-malonamide.

Background: Temporomandibular disorders (TMD) occur at an incidence of 5–12% in the general population. We aimed to investigate the rate of true-positives for a screening questionnaire for TMD (SQ-TMD) and differences in the characteristics between the true-positive and false-negative groups. Materials and Methods: Seventy-six individuals (16 men, 60 women; mean age, 41.1 ± 16.5 years) were selected from pa-tients with TMD who had visited the Temporomandibular Joint Clinic at Tokyo Medical and Dental University. The patients were assessed using a questionnaire that contained items on TMD screening (SQ-TMD); pain intensity (at rest, maximum mouth-opening, and chewing), as assessed using the visual analog scale (VAS); and TMD-related limitations of daily func-tion (LDF-TMD). A logistic regression analysis was performed to assess the factors potentially influencing the true-positive rate. Results: Of the 76 subjects, 62 (81.6%) were true-positive for the questionnaire based on the SQ-TMD scores. The mean VAS score for maximum mouth-opening and chewing and the mean LDF-TMD score were significantly greater in the true-positive group than those in the false-negative group. The results of the logistic regression analysis showed that only the VAS score for chewing was a statistically significant factor (P < 0.05). Conclusion: The true-positive rate of TMD using SQ-TMD was very high. The results indicate that SQ-TMD can be used to screen TMD in patients with moderate or severe pain and difficulty in living a healthy daily life.

An asymptomatic 48-year-old man presented with multiple aneurysms in a primary racemose hemangioma of the right bronchial artery. Bronchial arteriography revealed a tortuous artery with four fusiform aneurysms of varying sizes and aneurysmal dilatation with marked thrombus formation in the long segment of the distal portion. Because the tip of catheter could not pass beyond the aneurysmal dilatation, we performed balloon-occluded embolization using a mixture of N-butyl-2-cyanoacrylate (NBCA) and iodized oil. For four other aneurysms, we performed embolization using a coil alone or with NBCA. After 6 months, right bronchial arteriography revealed no enhancement of the aneurysms. Despite the rarity of this procedure, embolization with NBCA is a good option for bronchial artery aneurysm embolization.

The production of erythropoietin (EPO) by the kidneys, a principal hormone for the hematopoietic system, is reduced in patients with chronic kidney disease (CKD), eventually resulting in severe anemia. Although recombinant human EPO treatment improves anemia in patients with CKD, returning to full red blood cell production without fluctuations does not always occur. We established a method to generate EPO-producing cells from human induced pluripotent stem cells (hiPSCs) by modifying previously reported hepatic differentiation protocols. These cells showed increased EPO expression and secretion in response to low oxygen conditions, prolyl hydroxylase domain-containing enzyme inhibitors, and insulin-like growth factor 1. The EPO protein secreted from hiPSC-derived EPO-producing (hiPSC-EPO) cells induced the erythropoietic differentiation of human umbilical cord blood progenitor cells in vitro. Furthermore, transplantation of hiPSC-EPO cells into mice with CKD induced by adenine treatment improved renal anemia. Thus, hiPSC-EPO cells may be a useful tool for clarifying the mechanisms of EPO production and may be useful as a therapeutic strategy for treating renal anemia.

Multiple large clinical trials have shown that sodium-glucose cotransporter (SGLT) 2 inhibitors reduce the risk of renal events. However, the mechanism responsible for this outcome remains unknown. Here we investigated the effects of the SGLT2 inhibitor luseogliflozin on the development of renal fibrosis after renal ischemia/reperfusion injury in non-diabetic mice. Luseogliflozin significantly suppressed development of renal fibrosis, prevented peritubular capillary congestion/hemorrhage, attenuated CD31-positive cell loss, suppressed hypoxia, and increased vascular endothelial growth factor (VEGF)-A expression in the kidney after ischemia/reperfusion injury. Luseogliflozin failed to induce the above-mentioned protection in animals co-treated with sunitinib, a VEGF receptor inhibitor. Additionally, luseogliflozin reduced glucose uptake and increased VEGF-A expression in the kidneys of glucose transporter 2 (GLUT2)-downregulated mice following ischemia/reperfusion and in GLUT2-knock-down cells compared with those in normal controls. Withdrawal of glucose from cultured medium, to halt glucose uptake, remarkably increased VEGF-A expression and reversed the luseogliflozin-induced increase in VEGF-A expression in the proximal tubular cells. Thus, luseogliflozin prevented endothelial rarefaction and subsequent renal fibrosis after renal ischemia/reperfusion injury through a VEGF-dependent pathway induced by the dysfunction of proximal tubular glucose uptake in tubules with injury-induced GLUT2 downregulation.

Recent data indicate that klotho interacts with the renin-angiotensin system (RAS). However, the effects of klotho protein supplementation on hypertensive renal injury have not been examined yet. First, the in vivo experiments were performed using spontaneously hypertensive rats (SHR). To elucidate in vivo observations, the in vitro studies were carried out to examine the interactions between klotho protein and angiotensin type-1 (AT1) receptor with immunoprecipitation and cell culture (HK-2 cell) methods. Uninephrectomized SHRs were treated with exogenous klotho protein or vehicle. Exogenous klotho protein supplementation to uninephrectomized SHRs decreased blood pressure, renal angiotensin II levels, angiotensinogen expression, HIF-1α abundance, and medullary fibronectin with increased renal klotho expression and serum and urine klotho levels. Klotho supplementation also reduced kidney weight, renal phosphorylated Akt and mTOR abundance. Furthermore, klotho supplementation restored renal autoregulation of glomerular filtration rate and renal plasma flow, and improved pressure-induced natriuresis in SHR. Klotho protein bound to AT1 receptors without affecting the bindings of angiotensin II to AT1 receptor. Klotho decreased the presence of AT1 receptors on HK-2 cells, attenuating inositol triphosphate generation. Angiotensin II elevated angiotensinogen expression in HK-2 cells, and klotho protein suppressed angiotensin II-induced increases in angiotensinogen expression. Of note, although angiotensin II improves glomerular autoregulatory ability especially at lower pressure range, angiotensin II impairs pressure-induced natriuresis. Collectively, the present data demonstrate that klotho binds with the AT1 receptors to suppress angiotensin signal transduction and inactivate the renal RAS. In addition, our results suggest that exogenous klotho supplementation suppresses Akt-mTOR signaling to decline renal hypertrophy and restores renal autoregulatory ability in uninephrectomized SHRs. Finally, the present findings implicate that klotho supplementation inhibits HIF-1α pathway to suppress medullary fibrosis, presumably involved in improvements of pressure-natriuresis and reduction in blood pressure.

Chronic diabetic complications are classified as microvascular or macrovascular and contribute to mortality and loss of quality of life. Hyperglycemia plays a critical role in the pathogenesis of microvascular complications, such as diabetic retinopathy, incipient nephropathy, and neuropathy, while atherosclerosis contributes to the pathogenesis of macrovascular complications. Diabetes mellitus and hypertension are frequently present together. Among many microvascular diabetic complications, hypertension plays a predominant role in the progression of diabetic nephropathy by glomerular hyperfiltration. Hypertension also induces atherosclerosis in diabetes. Thus, hypertension is a high-risk factor for both microvascular and macrovascular chronic diabetic complications. In this review, we summarize the current knowledge on the pathophysiological mechanisms of microvascular and macrovascular chronic diabetic complications with particular emphasis on the contribution of hypertension. We also briefly discuss various options available for the treatment of each diabetic complication.

Retinal ganglion cell (RGC) loss associated with thinning of the retinal nerve fiber layer without elevated intraocular pressure (IOP) occurs after the systemic administration of aldosterone. Since it is important to determine the mechanism of cell death independent of the IOP, we examined gene expression changes in the retina after the systemic administration of aldosterone. Following subcutaneous implantation of an osmotic minipump into the mid-scapular region of rats, we administered an 80 μg/kg/day dose of aldosterone. Differences in the gene expression in the retina between normal rats and aldosterone-treated rats were investigated using microarrays. Real-time PCR was used to confirm the differential expression. Analysis of the microarray data sets revealed the upregulation of 24 genes and the downregulation of 24 genes of key apoptosis-specific genes. Real-time PCR revealed 4 genes (Cdkn1a, Tbox5, Pf4, Vdr) were upregulated while 12 genes (Acvr1c, Asns, Bard1, Card9, Crh, Fcgr1a, Inhba, Kcnh8, Lck, Phlda1, Ptprc, Sh3rf1) were downregulated. Significant increases and decreases were noted in several genes after the systemic administration of aldosterone. Further studies will need to be undertaken in order to definitively clarify the role of these genes in the eyes of animals with normal-tension glaucoma.

Natriuretic regulation of extracellular fluid volume homeostasis includes suppression of the renin-angiotensin-aldosterone system, pressure natriuresis, and reduced renal nerve activity, actions that concomitantly increase urinary Na+ excretion and lead to increased urine volume. The resulting natriuresis-driven diuretic water loss is assumed to control the extracellular volume. Here, we have demonstrated that urine concentration, and therefore regulation of water conservation, is an important control system for urine formation and extracellular volume homeostasis in mice and humans across various levels of salt intake. We observed that the renal concentration mechanism couples natriuresis with correspondent renal water reabsorption, limits natriuretic osmotic diuresis, and results in concurrent extracellular volume conservation and concentration of salt excreted into urine. This water-conserving mechanism of dietary salt excretion relies on urea transporter–driven urea recycling by the kidneys and on urea production by liver and skeletal muscle. The energy-intense nature of hepatic and extrahepatic urea osmolyte production for renal water conservation requires reprioritization of energy and substrate metabolism in liver and skeletal muscle, resulting in hepatic ketogenesis and glucocorticoid-driven muscle catabolism, which are prevented by increasing food intake. This natriuretic-ureotelic, water-conserving principle relies on metabolism-driven extracellular volume control and is regulated by concerted liver, muscle, and renal actions.

Activation of the Renin-Angiotensin-Aldosterone-System (RAAS) is proposed to play a role in the development of insulin resistance and type II diabetes. Angiotensin II (AngII) is a principal effector molecule that binds AT1 receptors (AT1R) in various tissues. Recent data shows that activated endothelial cells secrete protein disulfide isomerase (PDI), a multifunctional protein that has been shown to be critical to the initiation and regulation of thrombus formation. However, the effects of RAAS on PDI regulation are unknown. We hypothesized that RAAS activation would lead to increased PDI levels thus contributing to inflammation. First, we studied the in vitro effects of AngII on EA.hy926 human endothelial cells and measured PDI activity. Our results show that AngII increased PDI activity; an event that was blocked by preincubation with 0.5 M losartan, an AT1R antagonist (ARB) (P5). We then studied the obese Otsuka Long Evans Tokushima Fatty (OLETF) (n = 6/group) rats, a model of naturally increased AngII and RAAS mediated insulin resistance and hypertension. OLETF and their lean strain controls were randomly assigned to the following groups: (1) untreated Long Evans Tokushima Otsuka (lean, control); (2) untreated OLETF; (3) OLETF + ARB. Our results show that OLETF rats had increased insulin resistance and significantly greater circulating PDI activity than control rats (P

Hypoxia predisposes renal fibrosis. This study was conducted to identify novel approaches to ameliorate the pathogenic effect of hypoxia. Using human proximal tubular epithelial cells we showed that a pan-phosphodiesterase (PDE) inhibitor, 3-isobutyl-1-methylxanthine (IBMX) dose and time dependently downregulated hypoxia-inducible factor 1α (HIF-1α) mRNA expression, which was further augmented by addition of a transcriptional inhibitor, actinomycin D. IBMX also increased the cellular cyclic adenosine monophosphate (cAMP) level. Luciferase assay showed that blocking of protein kinase A (PKA) using H89 reduced, while 8-Br-cAMP agonized the repression of HIF-1α promoter activity in hypoxic condition. Deletion of cAMP response element binding sites from the HIF-1α promoter abrogated the effect of IBMX. Western blot and immunofluorescent study confirmed that the CoCl2 induced increased HIF-1α protein in whole cell lysate and in nucleus was reduced by the IBMX. Through this process, IBMX attenuated both CoCl2 and hypoxia induced mRNA expressions of two pro-fibrogenic factors, platelet-derived growth factor B and lysyl oxidase. Moreover, IBMX reduced production of a mesenchymal transformation factor, β-catenin; as well as protected against hypoxia induced cell-death. Taken together, our study showed novel evidence that the PDE inhibitor IBMX can downregulate the transcription of HIF-1α, and thus may attenuate hypoxia induced renal fibrosis.

How nutritional excess leads to inflammatory responses in metabolic syndrome is not well characterized. Here, we evaluated the effects of ω-3 polyunsaturated fatty acid specific G-protein coupled receptor 120 (GPR120) activation on inflammatory pathways in adipocytes, and the influence of this process on macrophage migration. Using 3T3-L1 adipocytes, we found that agonizing GPR120 using its synthetic ligand, GSK137647, attenuated both basal and lipopolysaccharide-induced production of interleukin-6 (IL-6) and C-C motif chemokine ligand 2 (CCL2). Moreover, the intervention reduced the phosphorylation of nuclear factor kappa B inhibitor alpha (IκBα) and nuclear translocation of nuclear factor kappa-B p65 subunit (p65). Furthermore, the silencing of GPR120 itself reduced IL-6 and CCL2 mRNA expression. Inhibition of protein kinase C (PKC) augmented the down-regulatory effect of GSK137647 on IL-6 and CCL2 mRNA. Using a luciferase assay to measure promoter activity of the IL-6 gene in mouse embryonic fibroblasts, we demonstrated that exogenous transfection of GPR120 alone reduced the promoter activity, which was augmented by GSK137647. Inhibition of PKC further reduced the promoter activity. Nevertheless, RAW 264.7 macrophages grown in conditioned medium collected from GSK137647-treated adipocytes attenuated the expressions of matrix metalloproteinases-9 and -3, and tissue inhibitor of metalloproteinase-1. Conditioned medium also inhibited the lipopolysaccharide-induced migration of these macrophages. Taken together, these findings provide critical evidence that although GPR120 is associated with a PKC-mediated pro-inflammatory pathway, the direct inhibitory effects of GPR120 on the nuclear factor kappa B pathway are anti-inflammatory. Moreover, GPR120 activity can attenuate the adipocyte-mediated enhanced production of extracellular matrix-modulating factors in macrophages and can reduce their migration by a paracrine mechanism.

Metabolic syndrome is often associated with disruption of circadian rhythm of systemic haemodynamics and cardiovascular disease. Experiments were conducted to investigate the effects of luseogliflozin, a selective SGLT2 inhibitor, on circadian rhythm of sympathetic nervous function and locomotor activity (LA) in metabolic syndrome rats. The difference in the low frequency component of systolic blood pressure between the dark and light period significantly increased in the luseogliflozin-treated SHRcp. LA also increased in the dark period compared with the light period following luseogliflozin treatment. These data suggest that circadian rhythm of sympathetic nervous function and LA is improved by luseogliflozin in metabolic syndrome rats, which may contribute to SGLT2 inhibitor-induced improvement of cardiovascular outcomes.

High glucose has been demonstrated to induce angiotensinogen (AGT) synthesis in the renal proximal tubular cells (RPTCs) of rats, which may further activate the intrarenal renin-angiotensin system (RAS) and contribute to diabetic nephropathy. This study aimed to investigate the effects of high glucose on AGT in the RPTCs of human origin and identify the glucose-responsive transcriptional factor(s) that bind(s) to the DNA sequences of AGT promoter in human RPTCs. Human kidney (HK)-2 cells were treated with normal glucose (5.5 mM) and high glucose (15.0 mM), respectively. Levels of AGT mRNA and AGT secretion of HK-2 cells were measured by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Consecutive 5'-end deletion mutant constructs and different site-directed mutagenesis products of human AGT promoter sequences were respectively transfected into HK-2 cells, followed by AGT promoter activity measurement through dual luciferase assay. High glucose significantly augmented the levels of AGT mRNA and AGT secretion of HK-2 cells, compared with normal glucose treatment. High glucose also significantly augmented AGT promoter activity in HK-2 cells transfected with the constructs of human AGT promoter sequences, compared with normal glucose treatment. Hepatocyte nuclear factor (HNF)-5 was found to be one of the glucose-responsive transcriptional factors of AGT in human RPTCs, since the mutation of its binding sites within AGT promoter sequences abolished the above effects of high glucose on AGT promoter activity as well as levels of AGT mRNA and its secretion. The present study has demonstrated, for the first time, that high glucose augments AGT in human RPTCs through HNF-5, which provides a potential therapeutic target for diabetic nephropathy.

The urinary angiotensinogen (AGT) excretion rate could be a novel biomarker for the intrarenal activity of the renin-angiotensin system. Little is known about the circadian rhythm of AGT levels in plasma or urine. In this short article, making use of data in plasma and urine of healthy volunteers and patients with chronic kidney diseases, we first report that we were unable to find evidence for a circadian rhythm of AGT under any condition. Next we critically discuss to what degree elevated urinary AGT levels might be considered an independent biomarker that is not simply the non-specific consequence of proteinuria.

Transcription factors (TFs) bind to DNA and regulate the transcription of nearby genes. However, only a small fraction of TF binding sites have such regulatory effects. Here we search for the predictors of functional binding sites by carrying out a systematic computational screening of a variety of contextual factors (histone modifications, nuclear lamin-bindings, and cofactor bindings). We used regression analysis to test if contextual factors are associated with upregulation or downregulation of neighboring genes following the induction or knockdown of the 9 TFs in mouse embryonic stem (ES) cells. Functional TF binding sites appeared to be either active (i.e., bound by P300, CHD7, mediator, cohesin, and SWI/SNF) or repressed (i.e., with H3K27me3 histone marks and bound by Polycomb factors). Active binding sites mediated the downregulation of nearby genes upon knocking down the activating TFs or inducing repressors. Repressed TF binding sites mediated the upregulation of nearby genes (e.g., poised developmental regulators) upon inducing TFs. In addition, repressed binding sites mediated repressive effects of TFs, identified by the downregulation of target genes after the induction of TFs or by the upregulation of target genes after the knockdown of TFs. The contextual factors associated with functions of DNA-bound TFs were used to improve the identification of candidate target genes regulated by TFs.

Stimulation of renal proximal tubule (PT) transport by angiotensin II (Ang II) is critical for regulation of BP. Notably, in rats, mice, and rabbits, the regulation of PT sodium transport by Ang II is biphasic: transport is stimulated by picomolar to nanomolar concentrations of Ang II but inhibited by nanomolar to micromolar concentrations of Ang II. However, little is known about the effects of Ang II on human PT transport. By functional analysis with isolated PTs obtained from nephrectomy surgery, we found that Ang II induces a dose-dependent profound stimulation of human PT transport by type 1 Ang II receptor (AT1)-dependent phosphorylation of extracellular signal-regulated kinase (ERK). In PTs of wild-type mice, the nitric oxide (NO) /cGMP/cGMP-dependent kinase II (cGKII) pathway mediated the inhibitory effect of Ang II. In PTs of cGKII-deficient mice, the inhibitory effect of Ang II was lost, but activation of the NO/cGMP pathway failed to phosphorylate ERK. Conversely, in human PTs, the NO/cGMP pathway mediated the stimulatory effect of Ang II by phosphorylating ERK independently of cGKII. These contrasting responses to the NO/cGMP pathway may largely explain the different modes of PT transport regulation by Ang II, and the unopposed marked stimulation of PT transport by high intrarenal concentrations of Ang II may be an important factor in the pathogenesis of human hypertension. Additionally, the previously unrecognized stimulatory effect of the NO/cGMP pathway on PT transport may represent a human-specific therapeutic target in hypertension.

(Pro)renin receptor [(P)RR], a trans-membrane receptor for renin and prorenin, is involved in the local activation of renin-angiotensin system (RAS) in the kidney. However, it remains to be determined whether (P)RR plays a role in the development of ischemic acute kidney injury (AKI).We examined the abundance of (P)RR, renin/prorenin, angiotensinogen (AGT), AT1 receptor (AT1R), phosphorylation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2) and nuclear factor-κB (NF-κB) by Western blots at 6, 24 and 48 h, and at 7 days after 45-min ischemic injury in rats. Intrarenal angiotensin II (Ang II) levels were determined by radioimmunoassay. We then tested whether the beneficial effects of oral loading of saline solution (1.0 % NaCl) for 7 days prior to ischemic injury were associated with changes in RAS components and ERK 1/2 and NF-κB phosphorylation in the kidney. We also examined the effect of AT1R blocker, olmesartan, on ischemia-induced changes of (P)RR downstream such as AGT and phosphorylation of ERK 1/2.Renal ischemia increased the abundance of (P)RR protein at 24 h, and peaked at 48 h. (P)RR was mainly stained in the connecting tubules and collecting ducts in control rats, while ischemia increased its immunointensity in the damaged proximal tubules. Renal ischemia increased phosphorylation of ERK 1/2 and NF-κB proteins as early as at 6 h. There was a significant increase in AGT and Ang II levels at 24 and 48 h. Prior saline loading prevented the increase in serum creatinine at 48 h (5.36 ± 1.26 vs. 3.38 ± 1.74 mg/dL, p0.05), and suppressed the increases in renal (P)RR, AGT and Ang II contents. Saline drinking also significantly blocked the ischemia-induced increases in phosphorylation of ERK 1/2 and NF-κB. In contrast, although treatment with olmesartan (10 mg/kg/day) for 14 days suppressed an increase of intrarenal AGT, olmesartan did not alleviate ischemic AKI, along with no change of (P)RR and phosphorylated ERK 1/2.These findings suggest that increased (P)RR is associated with activation of RAS-independent downstream such as ERK 1/2 and NF-κB phosphorylation in the ischemic kidney.

A new type of silicon-based Tunneling FET (TFET) using semiconducting silicide Mg2Si/Si hetero-junction as source-channel structure is proposed and the device simulation has been presented. With narrow bandgap of silicide and the conduction and valence band discontinuous at the hetero-junction, larger drain current and smaller subthreshold swing than those of Si homo-junction TFET can be obtained. Structural optimization study reveals that low Si channel impurity concentration and the alignment of the gate electrode edge to the hetero-junction lead to better performance of the TFET. Scaling of the gate length increases the off-state leakage current, however, the drain voltage (Vd) reduction in accordance with the gate scaling suppresses the phenomenon, keeping its high drivability.

The purpose of this study was to investigate the effect of the renin inhibitor, aliskiren, on retinal ischemia-reperfusion injury. Retinal ischemia was induced by increasing intraocular pressure to 130 mmHg. At 7 days after ischemia, retinal damage was evaluated by measuring the retinal thickness and the number of retinal ganglion cells. Western blot was used to measure changes in the (pro)renin receptor expression. Retinal mRNA expressions of prorenin, angiotensinogen and angiotensin II type 1 receptor (AT1-R) were measured by real-time polymerase chain reaction. Rats were treated with the renin inhibitor, aliskiren. Although the number of retinal ganglion cells and the inner retinal thickness were significantly decreased at 7 days after ischemia, treatment with aliskiren significantly inhibited retinal ischemic injury. Administration of aliskiren increased mRNA expression of prorenin in the retina at 3 h after the reperfusion. The expression of the (pro)renin receptor was not changed after ischemia-reperfusion injury with or without aliskiren. Although there was an increase in the retinal expression of AT1-R at 3 h after the reperfusion, aliskiren administration suppressed this expression. A renin inhibitor attenuated subsequent ischemic damage in the rat retina via the inhibition of the prorenin-induced angiotensin generation.

Intrarenal angiotensin II is increased in kidney diseases independently of plasma angiotensin II and is thought to promote progressive deterioration of renal architecture. Here we investigated the mechanism of enhanced renal angiotensin II generation in kidney glomerular diseases. For this, kidney- or liver-specific angiotensinogen gene (Agt) knockout was superimposed on the mouse model of inducible podocyte injury (NEP25). Seven days after induction of podocyte injury, renal angiotensin II was increased ninefold in NEP25 mice with intact Agt, accompanied by increases in urinary albumin and angiotensinogen excretion, renal angiotensinogen protein, and its mRNA. Kidney Agt knockout attenuated renal Agt mRNA but not renal angiotensin II, renal, or urinary angiotensinogen protein. In contrast, liver Agt knockout markedly reduced renal angiotensin II to 18.7% of that of control NEP25 mice, renal and urinary angiotensinogen protein, but not renal Agt mRNA. Renal angiotensin II had no relationship with renal Agt mRNA, or with renal renin mRNA, which was elevated in liver Agt knockouts. Kidney and liver dual Agt knockout mice showed phenotypes comparable to those of liver Agt knockout mice. Thus, increased renal angiotensin II generation upon severe podocyte injury is attributed to increased filtered angiotensinogen of liver origin resulting from loss of macromolecular barrier function of the glomerular capillary wall that occurs upon severe podocyte injury.

The cyclin-dependent kinase inhibitor p21 plays important roles in chronic renal disorders; however, its roles in response to acute renal stress are unclear. Here we evaluated p21 in acute kidney injury and ischemic preconditioning using wild-type and p21 knockout mice that underwent renal ischemia followed by reperfusion. The decline in renal function and histological changes were worse in the knockout than in wild-type mice. Ischemia/reperfusion increased p21 expression in the kidney of wild-type mice compared with sham surgery, suggesting p21 may confer tolerance to ischemia/reperfusion injury. We next tested whether p21 is associated with the protective effect of ischemic preconditioning, an established method to reduce ischemia/reperfusion injury. Ischemic preconditioning attenuated ischemia/reperfusion injury in wild-type but not p21-knockout mice. This preconditioning decreased the number of proliferating tubular cells before but increased them at 24 h after ischemia/reperfusion in the kidneys of wild-type mice. In p21-knockout mice, ischemic preconditioning did not change the number of proliferating cells before but decreased them after ischemia/reperfusion. Ischemic preconditioning increased renal p21 expression and the number of cells in the G1 phase of the cell cycle before ischemia/reperfusion compared with sham surgery. Thus, renal p21 is essential for the beneficial effects of renal ischemic preconditioning. Transient cell cycle arrest induced by ischemic preconditioning by a p21-dependent pathway seems to be important for subsequent tubular cell proliferation after ischemia/reperfusion.

The (pro)renin receptor ((P)RR) is expressed in several tissues including kidney, heart and brain, and is thought to regulate the tissue renin–angiotensin system (RAS) through the non-proteolytic activation of prorenin. (P)RR is cleaved by furin to generate soluble (P)RR (s(P)RR), which is secreted into the extracellular space. s(P)RR is a candidate biomarker reflecting the status of the tissue RAS. Here, we investigated the relationship between background factors and serum s(P)RR levels. We measured s(P)RR levels in 122 patients with essential hypertension (EH) and assessed the relationships between background factors and s(P)RR levels. Serum s(P)RR levels were 19.0 ± 4.9 ng ml−1. Single regression analyses showed that age (r =0.251, P