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result(s) for
"Minato Hiroyuki"
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Pretreatment with cilnidipine attenuates hypoxia/reoxygenation injury in HL-1 cardiomyocytes through enhanced NO production and action potential shortening
2020
Myocardial ischemia/reperfusion injury worsens in the absence of nitric oxide synthase (NOS). Cilnidipine, a Ca2+ channel blocker, has been reported to activate endothelial NOS (eNOS) and increases nitric oxide (NO) in vascular endothelial cells. We examined whether pretreatment with cilnidipine could attenuate cardiac cell deaths including apoptosis caused by hypoxia/reoxygenation (H/R) injury. HL-1 mouse atrial myocytes as well as H9c2 rat ventricular cells were exposed to H/R, and cell viability was evaluated by an autoanalyzer and flow cytometry; eNOS expression, NO production, and electrophysiological properties were also evaluated by western blotting, colorimetry, and patch clamping, respectively, in the absence and presence of cilnidipine. Cilnidipine enhanced phosphorylation of eNOS and NO production in a concentration-dependent manner, which was abolished by siRNAs against eNOS or an Hsp90 inhibitor, geldanamycin. Pretreatment with cilnidipine attenuated cell deaths including apoptosis during H/R; this effect was reproduced by an NO donor and a xanthine oxidase inhibitor. The NOS inhibitor L-NAME abolished the protective action of cilnidipine. Pretreatment with cilnidipine also attenuated H9c2 cell death during H/R. Additional cilnidipine treatment during H/R did not significantly enhance its protective action. There was no significant difference in the protective effect of cilnidipine under normal and high Ca2+ conditions. Action potential duration (APD) of HL-1 cells was shortened by cilnidipine, with this shortening augmented after H/R. L-NAME attenuated the APD shortening caused by cilnidipine. These findings indicate that cilnidipine enhances NO production, shortens APD in part by L-type Ca2+ channel block, and thereby prevents HL-1 cell deaths during H/R.
Journal Article
Azelnidipine protects HL-1 cardiomyocytes from hypoxia/reoxygenation injury by enhancement of NO production independently of effects on gene expression
by
Minato, Hiroyuki
,
Otsuki, Akihiro
,
Yamamoto, Kazuhiro
in
Acetylcysteine
,
Action potential
,
Action Potentials - drug effects
2024
It remains to be elucidated whether Ca
2+
antagonists induce pharmacological preconditioning to protect the heart against ischemia/reperfusion injury. The aim of this study was to determine whether and how pretreatment with a Ca
2+
antagonist, azelnidipine, could protect cardiomyocytes against hypoxia/reoxygenation (H/R) injury in vitro. Using HL-1 cardiomyocytes, we studied effects of azelnidipine on NO synthase (NOS) expression, NO production, cell death and apoptosis during H/R. Action potential durations (APDs) were determined by the whole-cell patch-clamp technique. Azelnidipine enhanced endothelial NOS phosphorylation and NO production in HL-1 cells under normoxia, which was abolished by a heat shock protein 90 inhibitor, geldanamycin, and an antioxidant,
N
-acetylcysteine. Pretreatment with azelnidipine reduced cell death and shortened APDs during H/R. These effects of azelnidipine were diminished by a NOS inhibitor, L-NAME, but were influenced by neither a T-type Ca
2+
channel inhibitor, NiCl
2
, nor a N-type Ca
2+
channel inhibitor, ω-conotoxin. The azelnidipine-induced reduction in cell death was not significantly enhanced by either additional azelnidipine treatment during H/R or increasing extracellular Ca
2+
concentrations. RNA sequence (RNA-seq) data indicated that azelnidipine-induced attenuation of cell death, which depended on enhanced NO production, did not involve any significant modifications of gene expression responsible for the NO/cGMP/PKG pathway. We conclude that pretreatment with azelnidipine protects HL-1 cardiomyocytes against H/R injury via NO-dependent APD shortening and L-type Ca
2+
channel blockade independently of effects on gene expression.
Journal Article
Hsp70 promotes maturation of uromodulin mutants that cause familial juvenile hyperuricemic nephropathy and suppresses cellular damage
2022
BackgroundFamilial juvenile hyperuricemic nephropathy (FJHN) is an autosomal dominant disorder caused by mutations in UMOD. Here we studied effects of genetic expression and pharmacological induction of Hsp70 on the UMOD mutants C112Y and C217G.MethodsWe expressed wild type (WT), C112Y and C217G in HEK293 cells and studied their maturation and cellular damage using western blot and flow cytometry.ResultsExpression of C112Y or C217G increased pro-apoptotic proteins, decreased anti-apoptotic proteins, and induced cellular apoptosis as examined by annexin V staining and flow cytometry. Overexpression of Hsp70 or administration of an Hsp70 inducer geranylgeranylacetone (GGA) promoted maturation of the mutant proteins, increased their secreted forms, normalized the levels of pro- and anti-apoptotic proteins and suppressed apoptosis.ConclusionThese findings indicated that Hsp70 enhanced maturation of C112Y and C217G and reduced cellular apoptosis, suggesting that Hsp70 induction might be of a therapeutic value for treatment of FJHN.
Journal Article
B38-CAP is a bacteria-derived ACE2-like enzyme that suppresses hypertension and cardiac dysfunction
2020
Angiotensin-converting enzyme 2 (ACE2) is critically involved in cardiovascular physiology and pathology, and is currently clinically evaluated to treat acute lung failure. Here we show that the B38-CAP, a carboxypeptidase derived from
Paenibacillus
sp. B38, is an ACE2-like enzyme to decrease angiotensin II levels in mice. In protein 3D structure analysis, B38-CAP homolog shares structural similarity to mammalian ACE2 with low sequence identity. In vitro, recombinant B38-CAP protein catalyzed the conversion of angiotensin II to angiotensin 1–7, as well as other known ACE2 target peptides. Treatment with B38-CAP suppressed angiotensin II-induced hypertension, cardiac hypertrophy, and fibrosis in mice. Moreover, B38-CAP inhibited pressure overload-induced pathological hypertrophy, myocardial fibrosis, and cardiac dysfunction in mice. Our data identify the bacterial B38-CAP as an ACE2-like carboxypeptidase, indicating that evolution has shaped a bacterial carboxypeptidase to a human ACE2-like enzyme. Bacterial engineering could be utilized to design improved protein drugs for hypertension and heart failure.
The enzyme ACE2 is involved in cardiac pathology and can counteract heart failure and other cardio-pulmonary diseases. Here the authors show that bacteria produce an ACE2-like enzyme that is effective in suppressing cardiac hypertrophy and fibrosis in mice.
Journal Article
Effectiveness of one-shot dual-energy subtraction chest radiography with flat-panel detector in distinguishing between calcified and non-calcified nodules
by
Hirata, Tetsuhiro
,
Yamazaki, Motohiko
,
Minato, Kojiro
in
631/114/1564
,
692/699/67/2321
,
Area Under Curve
2023
The purpose of this study was to evaluate the added value of the soft tissue image obtained by the one-shot dual-energy subtraction (DES) method using a flat-panel detector compared with the standard image alone in distinguishing calcified from non-calcified nodules on chest radiographs. We evaluated 155 nodules (48 calcified and 107 non-calcified) in 139 patients. Five radiologists (readers 1 − 5) with 26, 14, 8, 6 and 3 years of experience, respectively, evaluated whether the nodules were calcified using chest radiography. CT was used as the gold standard of calcification and non-calcification. Accuracy and area under the receiver operating characteristic curve (AUC) were compared between analyses with and without soft tissue images. The misdiagnosis ratio (false positive plus false negative ratios) when nodules and bones overlapped was also examined. The accuracy of all radiologists increased after adding soft tissue images (readers 1 − 5: 89.7% vs. 92.3% [P = 0.206], 83.2% vs. 87.7% [P = 0.178], 79.4% vs. 92.3% [P < 0.001], 77.4% vs. 87.1% [P = 0.007], and 63.2% vs. 83.2% [P < 0.001], respectively). AUCs for all the readers improved, except for reader 2 (readers 1 − 5: 0.927 vs. 0.937 [P = 0.495], 0.853 vs. 0.834 [P = 0.624], 0.825 vs. 0.878 [P = 0.151], 0.808 vs. 0.896 [P < 0.001], and 0.694 vs. 0.846 [P < 0.001], respectively). The misdiagnosis ratio for nodules that overlapped with the bone decreased after adding soft tissue images in all readers (11.5% vs. 7.6% [P = 0.096], 17.6% vs. 12.2% [P = 0.144], 21.4% vs. 7.6% [P < 0.001], 22.1% vs. 14.5% [P = 0.050] and 35.9% vs. 16.0% [P < 0.001], respectively), particularly that of readers 3 − 5. In conclusion, the soft tissue images obtained using one-shot DES with a flat-panel detector have added value in distinguishing calcified from non-calcified nodules on chest radiographs, especially for less experienced radiologists.
Journal Article
Association between preoperative proximal thoracic curve flexibility and postoperative spontaneous correction in Lenke type 1 adolescent idiopathic scoliosis: a retrospective study
2025
Lenke type 1 adolescent idiopathic scoliosis (AIS) is characterized by a structural main thoracic (MT) curve and a non-structural proximal thoracic (PT) curve. Accurate prediction of postoperative PT curve correction is crucial for achieving optimal surgical outcomes, including postoperative shoulder balance. This study aimed to determine which preoperative lateral bending and traction radiographs are most appropriate for assessing spontaneous postoperative PT curve correction. Fifty-five patients with Lenke type 1 AIS who underwent PSF between January 2006 and January 2020 were included. Preoperative curve flexibility was assessed using side-bending (SB), fulcrum-bending (FB), and traction (TR) radiographs. Radiographic measurements were conducted preoperatively, immediately postoperatively, and at the 2-year follow-up. The average preoperative Cobb angles for PT, main thoracic (MT), and thoracolumbar/lumbar (TL/L) curves were 24.7°, 53.5°, and 32.4°, respectively. SB radiographs demonstrated a significant correlation with 2-year postoperative PT Cobb angles (r = 0.526, p < 0.001), with no significant difference between preoperative SB measurements and actual 2-year postoperative outcomes (mean difference − 0.03°; 95%CI − 1.57 to 1.49;
p
= 0.88). FB radiographs accurately reflected MT correction but overestimated PT correction (mean difference 2.29°; 95%CI − 0.51 to 5.10;
p
= 0.11), while TR radiographs underestimated PT correction. These results indicate that SB radiographs can be used as a reliable reference for estimating postoperative spontaneous PT curve correction in Lenke type 1 AIS.
Journal Article
Pembrolizumab versus chemotherapy in recurrent, advanced urothelial cancer in Japanese patients: a subgroup analysis of the phase 3 KEYNOTE-045 trial
by
Nishiyama Hiroyuki
,
Sassa Naoto
,
Enokida Hideki
in
Antitumor activity
,
Bladder cancer
,
Cancer
2020
BackgroundThe open-label, randomized, active-controlled KEYNOTE-045 study (NCT02256436) showed that second-line pembrolizumab significantly improved overall survival (OS) of patients with advanced/metastatic urothelial cancer (UC) that progressed after first-line platinum-containing chemotherapy, compared with standard chemotherapy (paclitaxel, docetaxel, or vinflunine). Pembrolizumab is approved for patients with bladder cancer in Japan.Patients and methodsAnalysis was performed in the subgroup of Japanese patients enrolled in the KEYNOTE-045 study. Coprimary end points were OS and progression-free survival (PFS). Objective response rate (ORR) and safety were secondary end points.ResultsFifty-two Japanese patients (pembrolizumab, n = 30; chemotherapy, n = 22) were followed up for a median of 26.1 months. Patients who received pembrolizumab compared with chemotherapy had a 19% lower risk for death (hazard ratio [HR] 0.81, 95% CI 0.44–1.50); after adjusting for baseline covariates, the HR for OS was 0.61 (95% CI 0.32–1.15). The 24-month OS rate was higher with pembrolizumab (26.9% vs 14.3%). PFS was 2.0 and 4.9 months for pembrolizumab and chemotherapy, respectively (HR 1.71, 95% CI 0.95–3.08). ORR was similar for pembrolizumab and chemotherapy (20.0% vs 18.2%); durability of response was higher with pembrolizumab: 67% and 33% of patients, respectively, maintained a response for > 12 months. Treatment-related adverse events, including grade 3–5 events, occurred less frequently with pembrolizumab.ConclusionsPembrolizumab provided durable antitumor activity in patients with locally advanced/metastatic UC that progressed after platinum-containing chemotherapy in the overall population and in the Japanese subgroup; safety profile was consistent with that previously observed for pembrolizumab.
Journal Article
Physical and biological properties of a novel anti-adhesive punctate uneven gelatin film
2025
Since abdominal adhesion are quite problematic in abdominal and pelvic surgery, the conventional HA/CMC film are commonly used as an anti-adhesive material. However, such types are difficult to be rolled and delivered through the port of laparoscopic surgical devices due to adherence to the laparoscopic port or other parts of the films. To create an anti-adhesion film with more favorable handling properties and anti-adhesive effect, we developed a novel punctate uneven gelatin film (PU GF). In this study, we examined the physical strength, flexibilities and adhesiveness between film to tissues or film each other, compared to the conventional film and the flat gelatin film (Flat GF). In addition, we investigated the cell proliferation on each film and the anti-adhesive effect of the films and those reattachment possibility using a rat cecum abrasion model. The PU GF showed excellent tensile strength, ductility, and adherence to tissue compared to Flat GF and the conventional film. Moreover, the adherence of PU GF to the other film and to a silicon sheet were much lower than those of the Flat GF and conventional film. The proliferation of cells in PU GF and Flat GF were suppressed compared with control, though increased with time. The anti-adhesive scores of the PU GF after one time and re-attachment were significantly higher than that of non-covered control, although there was no significant difference between that of the conventional film and control. Our findings suggest that PU GF improve handling properties of laparoscopic surgery as it has excellent physical strength, ductility, and adherence to tissue, and low adherence to trocar. In addition, the punctate film may be more useful with the re-attachability without tearing and to retained sufficient anti-adhesion effect.
Journal Article
The phytoplasmal virulence factor TENGU causes plant sterility by downregulating of the jasmonic acid and auxin pathways
2014
Despite plants infected by pathogens are often unable to produce offspring, it remains unclear how sterility is induced in host plants. In this study, we demonstrate that TENGU, a phytoplasmal virulence peptide known as a dwarfism inducer, acts as an inducer of sterility. Transgenic expression of TENGU induced both male and female sterility in
Arabidopsis thaliana
flowers similar to those observed in double knockout mutants of
auxin response factor 6
(
ARF6
) and
ARF8
, which are known to regulate floral development in a jasmonic acid (JA)-dependent manner. Transcripts of
ARF6
and
ARF8
were significantly decreased in both
tengu
-transgenic and phytoplasma-infected plants. Furthermore, JA and auxin levels were actually decreased in
tengu
-transgenic buds, suggesting that TENGU reduces the endogenous levels of phytohormones by repressing
ARF6
and
ARF8
, resulting in impaired flower maturation. TENGU is the first virulence factor with the effects on plant reproduction by perturbation of phytohormone signaling.
Journal Article