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29 result(s) for "Nishigaki, Yuka"
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Raman spectroscopy of large extracellular vesicles derived from human microvascular endothelial cells to detect benzoapyrene exposure
Extracellular vesicles (EVs) have shown great potential as biomarkers since they reflect the physio-pathological status of the producing cell. In the context of cytotoxicity, it has been found that exposing cells to toxicants leads to changes in protein expression and the cargo of the EVs they produce. Here, we studied large extracellular vesicles (lEVs) derived from human microvascular endothelial cells (HMEC-1) to detect the modifications induced by cell exposure to benzo[a]pyrene (B[a]P). We used a custom CaF2-based biochip which allowed hyphenated techniques of investigation: surface plasmon resonance imaging (SPRi) to monitor the adsorption of objects, atomic force microscopy (AFM) to characterise EVs’ size and morphology, and Raman spectroscopy to detect molecular modifications. Results obtained on EVs by Raman microscopy and tip-enhanced Raman spectroscopy (TERS) showed significant differences induced by B[a]P in the high wavenumber region of Raman spectra (2800 to 3000 cm−1), corresponding mainly to lipid modifications. Two types of spectra were detected in the control sample. A support vector machine (SVM) model was trained on the pre-processed spectral data to differentiate between EVs from cells exposed or not to B[a]P at the spectrum level; this model could achieve a sensitivity of 88% and a specificity of 99.5%. Thus, this experimental setup facilitated the distinction between EVs originating from two cell culture conditions and enabled the discrimination of EV subsets within one cell culture condition.
Inhibition of GCN2 sensitizes ASNS-low cancer cells to asparaginase by disrupting the amino acid response
General control nonderepressible 2 (GCN2) plays a major role in the cellular response to amino acid limitation. Although maintenance of amino acid homeostasis is critical for tumor growth, the contribution of GCN2 to cancer cell survival and proliferation is poorly understood. In this study, we generated GCN2 inhibitors and demonstrated that inhibition of GCN2 sensitizes cancer cells with low basal-level expression of asparagine synthetase (ASNS) to the antileukemic agent L-asparaginase (ASNase) in vitro and in vivo. We first tested acute lymphoblastic leukemia (ALL) cells and showed that treatment with GCN2 inhibitors rendered ALL cells sensitive to ASNase by preventing the induction of ASNS, resulting in reduced levels of de novo protein synthesis. Comprehensive gene-expression profiling revealed that combined treatment with ASNase and GCN2 inhibitors induced the stress-activated MAPK pathway, thereby triggering apoptosis. By using cell-panel analyses, we also showed that acute myelogenous leukemia and pancreatic cancer cells were highly sensitive to the combined treatment. Notably, basal ASNS expression at protein levels was significantly correlated with sensitivity to combined treatment. These results provide mechanistic insights into the role of GCN2 in the amino acid response and a rationale for further investigation of GCN2 inhibitors for the treatment of cancer.
Human iPSC-derived NK cells armed with CCL19, CCR2B, high-affinity CD16, IL-15, and NKG2D complex enhance anti-solid tumor activity
Background Studies of chimeric antigen receptor (CAR)-T and -Natural killer (NK) cells have shown promising results in treating hematological malignancies. However, there are still obstacles to effectively treating solid tumors. These include the challenges of CAR-T cell homing and infiltration, the presence of immunosuppressive microenvironments, and the potential for antigen escape in solid tumors. To overcome the known limitations of immune cell therapy, we engineered human induced pluripotent stem cell (hiPSC)-derived NK cells armed with CCL19, CCR2B, high-affinity CD16, IL-15, and NKG2D-DAP10 complex. Methods We introduced the six genes, CCL19 , CCR2B , FCGR3A (CD16), IL-15 , KLRK1 (NKG2D), and HCST (DAP10), which were controlled under human EF1a promoter, into hiPSCs using the piggyBac system and differentiated them into NK cells. We evaluate the antitumor function, including killing activity, antibody-dependent cytotoxicity, migration ability, and recruitment of dendritic cells. In addition, in vivo antitumor activity was determined by using an orthotopic lung cancer mouse model. Results The gene-engineered hiPSCs expressed all six transgenes, showed normal karyotypes, and were able to differentiate into CD56 + NK cells. The gene-engineered hiPSC-derived NK (eNK) cells showed improvement in viability without additional cytokine supplement in vitro and in vivo. Overexpression of NKG2D complex and high-affinity CD16 enhanced the antitumor function of the eNK cells. Forced expression of CCR2B enhanced eNK cell tumor infiltration. Forced expression of CCL19 endowed the eNK cells with the ability to recruit dendritic cells. We found that the eNK cells were able to lyse HLA-E-expressing tumor cells, but not normal human cells. Moreover, eNK cells demonstrated superior anti-tumor activity in an orthotropic lung cancer mouse model. Conclusion These proof-of-concept studies demonstrate the promise of our eNK cells as a novel adoptive cell therapy product for the treatment of solid tumors. Graphical abstract
High-salt intake accelerates functional and histological renal damage associated with renal tissue overexpression of (pro)renin receptors and AT1 receptors in spontaneously hypertensive rats
ObjectiveThis study aimed to investigate the effect of combination of high-salt intake and hypertension on renal functional and histological damage, associated with renal (pro)renin receptor [(P)RR] and AT1 receptor in rats.MethodsWistar Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) received regular rat chow (normal-salt diet 0.9%) or high-salt rat chow (high-salt diet 8.9%) for 6 weeks from 6 to 12 weeks of age. Systolic blood pressure, serum creatinine and blood urea nitrogen (BUN) were measured. Histological analysis of the kidney was performed. Western blot analysis was performed on the expressions of (P)RR, angiotensinogen and AT1 receptor in the kidney.ResultsHigh-salt intake significantly increased systolic blood pressure in WKYs and especially in SHRs. High-salt intake significantly increased serum creatinine and BUN, and accelerated renal tubulointerstitial fibrosis and glomerular sclerosis in SHRs. High-salt intake significantly enhanced the renal tissue expressions of (P)RR, angiotensinogen and AT1 receptor in SHRs.ConclusionHigh-salt intake accelerates functional and histological renal damage associated with renal tissue overexpression of (P)RR and AT1 receptors in SHRs.
Azilsartan attenuates cardiac damage caused by high salt intake through the downregulation of the cardiac (pro)renin receptor and its downstream signals in spontaneously hypertensive rats
We examined whether the stimulation of the angiotensin II AT1 receptor increases the expression of the cardiac (pro)renin receptor ((P)RR) and its downstream signals and whether the blockade of the angiotensin II AT1 receptor by azilsartan decreases the expression of the cardiac (P)RR and its signaling in spontaneously hypertensive rats (SHRs) with a high-salt intake. Rats received normal-salt (0.9%) chow, high-salt (8.9%) chow, normal-salt chow with 1 mg/day of azilsartan, and high-salt chow with 1 mg/day of azilsartan from 6 to 12 weeks of age. Rats with normal-salt chow were administered 100 ng/kg/min of angiotensin II by osmotic minipump from 6 to 12 weeks of age. A high-salt diet and angiotensin II significantly increased the systolic blood pressure; overexpressed cardiac (P)RR, phosphorylated (p)-ERK1/2, p-p38MAPK, p-HSP27, and TGF-ß1; enhanced cardiac interstitial and perivascular fibrosis, cardiomyocyte size, interventricular septum (IVS) thickness, and left ventricular (LV) end-diastolic dimension; and decreased LV fractional shortening. Azilsartan decreased systolic blood pressure, cardiac expressions of (P)RR, p-ERK1/2, p-p38MAPK, p-HSP27, and TGF-ß1, cardiac interstitial and perivascular fibrosis, cardiomyocyte size, and LV diastolic dimension, and improved LV fractional shortening. In conclusion, azilsartan attenuates cardiac damage caused by high salt intake through the downregulation of the cardiac (pro)renin receptor and its downstream signals in SHRs.
High Salt Intake Damages the Heart through Activation of Cardiac (Pro) Renin Receptors Even at an Early Stage of Hypertension
It has not yet been fully elucidated whether cardiac tissue levels of prorenin, renin and (P)RR are activated in hypertension with a high salt intake. We hypothesized that a high salt intake activates the cardiac tissue renin angiotensin system and prorenin-(pro)renin receptor system, and damages the heart at an early stage of hypertension. Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) received regular (normal-salt diet, 0.9%) and high-salt (8.9%) chow for 6 weeks from 6 to 12 weeks of age. The systolic blood pressure, plasma renin activity (PRA) and plasma angiotensin II concentration were measured, and the protein expressions of prorenin, (pro)renin receptor, angiotensinogen, angiotensin II AT1 receptor, ERK1/2, TGF-β, p38MAPK and HSP27 in the myocardium were investigated. The cardiac function was assessed by echocardiography, and histological analysis of the myocardium was performed. The high-salt diet significantly increased the systolic blood pressure, and significantly reduced the PRA and plasma angiotensin II concentration both in the WKYs and SHRs. Cardiac expressions of prorenin, renin, (P)RR, angiotensinogen, angiotensin II AT1 receptor, phosphorylated (p)-ERK1/2, p-p38MAPK, TGF-β and p-HSP27 were significantly increased by the high salt diet both in the WKYs and SHRs. The high-salt diet significantly increased the interventricular septum thickness and cardiomyocyte size, and accelerated cardiac interstitial and perivascular fibrosis both in the WKYs and SHRs. On the other hand, dilatation of left ventricular end-diastolic dimension and impairment of left ventricular fractional shortening was shown only in salt loaded SHRs. The high-salt diet markedly accelerated cardiac damage through the stimulation of cardiac (P)RR and angiotensin II AT1 receptor by increasing tissue prorenin, renin and angiotensinogen and the activation of ERK1/2, TGF-β, p38MAPK and HSP27 under higher blood pressure.
Excessively low salt diet damages the heart through activation of cardiac (pro) renin receptor, renin-angiotensin-aldosterone, and sympatho-adrenal systems in spontaneously hypertensive rats
A high salt intake causes hypertension and leads to cardiovascular disease. Therefore, a low salt diet is now recommended to prevent hypertension and cardiovascular disease. However, it is still unknown whether an excessively low salt diet is beneficial or harmful for the heart. Wistar Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) received normal salt chow (0.9% salt diet) and excessively low salt chow (0.01% salt diet referred to as saltless diet) for 8 weeks from 8 to 16 weeks of age. The effects of the excessively low salt diet on the cardiac (pro) renin receptor, renin-angiotensin-aldosterone, and sympatho-adrenal systems were investigated. The excessively low salt diet did not affect the systolic blood pressure but significantly increased the heart rate both in WKYs and SHRs. The excessively low salt diet significantly elevated plasma renin activity, plasma angiotensin I, II and aldosterone concentrations, and plasma noradrenaline and adrenaline concentrations both in WKYs and SHRs. Cardiac expressions of renin, prorenin, (P)RR, angiotensinogen, and angiotensin II AT1 receptor and phosphorylated (p)-ERK1/2, p-HSP27, p-38MAPK, and TGF-ß1 were significantly enhanced by the excessively low salt diet in both WKYs and SHRs. The excessively low salt diet accelerated cardiac interstitial and perivascular fibrosis and increased the cardiomyocyte size and interventricular septum thickness in WKYs and SHRs but the extent was greater in SHRs. An excessively low salt diet damages the heart through activation of plasma renin-angiotensin-aldosterone and sympatho-adrenal systems and activation of cardiac (P)RR and angiotensin II AT1 receptor and their downstream signals both in WKYs and SHRs.
Phylogenetic and Structural Diversity in the Feline Leukemia Virus Env Gene
Feline leukemia virus (FeLV) belongs to the genus Gammaretrovirus, and causes a variety of neoplastic and non-neoplastic diseases in cats. Alteration of viral env sequences is thought to be associated with disease specificity, but the way in which genetic diversity of FeLV contributes to the generation of such variants in nature is poorly understood. We isolated FeLV env genes from naturally infected cats in Japan and analyzed the evolutionary dynamics of these genes. Phylogenetic reconstructions separated our FeLV samples into three distinct genetic clusters, termed Genotypes I, II, and III. Genotype I is a major genetic cluster and can be further classified into Clades 1-7 in Japan. Genotypes were correlated with geographical distribution; Genotypes I and II were distributed within Japan, whilst FeLV samples from outside Japan belonged to Genotype III. These results may be due to geographical isolation of FeLVs in Japan. The observed structural diversity of the FeLV env gene appears to be caused primarily by mutation, deletion, insertion and recombination, and these variants may be generated de novo in individual cats. FeLV interference assay revealed that FeLV genotypes did not correlate with known FeLV receptor subgroups. We have identified the genotypes which we consider to be reliable for evaluating phylogenetic relationships of FeLV, which embrace the high structural diversity observed in our sample. Overall, these findings extend our understanding of Gammaretrovirus evolutionary patterns in the field, and may provide a useful basis for assessing the emergence of novel strains and understanding the molecular mechanisms of FeLV transmission in cats.
LOX-1 Plays an Important Role in Ischemia-Induced Angiogenesis of Limbs
LOX-1, lectin-like oxidized low-density lipoprotein (LDL) receptor-1, is a single transmembrane receptor mainly expressed on endothelial cells. LOX-1 mediates the uptake of oxidized LDL, an early step in atherosclerosis; however, little is known about whether LOX-1 is involved in angiogenesis during tissue ischemia. Therefore, we examined the role of LOX-1 in ischemia-induced angiogenesis in the hindlimbs of LOX-1 knockout (KO) mice. Angiogenesis was evaluated in a surgically induced hindlimb ischemia model using laser Doppler blood flowmetry (LDBF) and histological capillary density (CD) and arteriole density (AD). After right hindlimb ischemia, the ischemic/nonischemic hindlimb blood flow ratio was persistently lower in LOX-1 KO mice than in wild-type (WT) mice. CD and AD were significantly smaller in LOX-1 KO mice than in WT mice on postoperative day 14. Immunohistochemical analysis revealed that the number of macrophages infiltrating ischemic tissues was significantly smaller in LOX-1 KO mice than in WT mice. The number of infiltrated macrophages expressing VEGF was also significantly smaller in LOX-1 KO mice than in WT mice. Western blot analysis and ROS production assay revealed that LOX- KO mice show significant decrease in Nox2 expression, ROS production and HIF-1α expression, the phosphorylation of p38 MAPK and NF-κB p65 subunit as well as expression of redox-sensitive vascular cell adhesion molecule-1 (VCAM-1) and LOX-1 itself in ischemic muscles, which is supposed to be required for macrophage infiltration expressing angiogenic factor VEGF. Reduction of VEGF expression successively suppressed the phosphorylation of Akt and eNOS, which accelerated angiogenesis, in the ischemic leg of LOX-1 KO mice. Our findings indicate that LOX-1 plays an important role in ischemia-induced angiogenesis by 1) Nox2-ROS-NF-κB activation, 2) upregulated expression of adhesion molecules: VCAM-1 and LOX-1 and 3) promoting macrophage infiltration, which expresses angiogenic factor VEGF.
A randomized phase II trial of cisplatin plus gemcitabine versus carboplatin plus gemcitabine in patients with completely resected non-small cell lung cancer: Hokkaido Lung Cancer Clinical Study Group Trial (HOT0703)
PurposeThis study evaluated the efficacy and safety of platinum plus gemcitabine (P/G) combinations as postoperative adjuvant chemotherapies for non-small cell lung cancer.MethodsPatients with postoperative stage IB–IIIA non-small cell lung cancer were randomly assigned to receive either cisplatin plus gemcitabine (GP arm) or carboplatin plus gemcitabine (GC arm) every 3 weeks for four cycles. The primary endpoint was 2-year disease-free survival (DFS). Secondary endpoints were safety, feasibility, overall survival (OS), and biomarker analyses.ResultsA total of 102 patients were randomized (stage IB, 22%; II, 36%; IIIA, 42%; histology: 74% adenocarcinoma). Of the 51 patients in each arm, 37 (73%) completed 4 cycles. During follow-up (median 5.8 years; range 0.1–9.7 years), estimated DFS and OS rates at 2 years were 59.6% and 86.3% with GP and 68.0% and 86.3% with GC, respectively. No significant difference in DFS was noted between arms (P = 0.163), although 3-, 4-, and 5-year DFS rates were higher with GC. Hematological toxic effects were comparable and non-hematological toxic effects were infrequent. DFS was significantly higher in the excision repair cross-complementation group 1 (ERCC1)-low group than in the ERCC1-high group for the GP arm (P = 0.045).ConclusionBoth P/G combination regimens were feasible and well-tolerated, and thus may represent valid options for postoperative adjuvant treatment of non-small cell lung cancer. Although no significant differences in DFS were evident between regimens, the present data favor the adoption of GC for further evaluation.Clinical trial registrationUMIN-CTR (https://www.umin.ac.jp/ctr/) identifier: UMIN000000913.