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353 result(s) for "Uehara, Takashi"
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Integrated extracellular microRNA profiling for ovarian cancer screening
A major obstacle to improving prognoses in ovarian cancer is the lack of effective screening methods for early detection. Circulating microRNAs (miRNAs) have been recognized as promising biomarkers that could lead to clinical applications. Here, to develop an optimal detection method, we use microarrays to obtain comprehensive miRNA profiles from 4046 serum samples, including 428 patients with ovarian tumors. A diagnostic model based on expression levels of ten miRNAs is constructed in the discovery set. Validation in an independent cohort reveals that the model is very accurate (sensitivity, 0.99; specificity, 1.00), and the diagnostic accuracy is maintained even in early-stage ovarian cancers. Furthermore, we construct two additional models, each using 9–10 serum miRNAs, aimed at discriminating ovarian cancers from the other types of solid tumors or benign ovarian tumors. Our findings provide robust evidence that the serum miRNA profile represents a promising diagnostic biomarker for ovarian cancer. Screening methods for early detection of ovarian cancer is technically difficult. Here, the authors investigated circulating microRNA in human blood serum and developed a model using 10 microRNAs to discern between ovarian cancer and being ovarian tumors, solid tumors, and non-cancer patients.
Nitric oxide induces p53-mediated cell death in human nasal epithelial cells
Nitric oxide (NO) is a key signaling molecule that plays a vital role in maintaining homeostasis of physiological processes such as immune responses and neurotransmission. However, excessive NO production during inflammatory responses to infection can lead to cytotoxicity and tissue damage. The nasal epithelial barrier is a crucial first line of immunological defense against viral infections, and it is likely exposed to excessive NO levels during chronic inflammation. Therefore, clarifying the effects of NO on this barrier is thus critical. In this study, we investigated the biological effects of sustained NO exposure on RPMI2650 human nasal epithelial cells. Post-NO exposure transcriptomic analyses revealed significant upregulation of genes involved in the p53 signaling pathway. RT-qPCR analyses confirmed the temporal upregulation of p53 target genes associated with apoptosis and cell cycle regulation. These gene expression changes downregulated cell proliferation and induced cell death. Our findings suggest that excessive NO exposure induces nasal epithelial cell death via the p53 pathway, which over the long term can result in tissue damage and dysfunction under inflammatory conditions. These results provide new insights into how prolonged NO exposure affects the nasal epithelial cells and may contribute to the progression of chronic infectious diseases.
Characterization of pathological changes in the olfactory system of mice exposed to methylmercury
Methylmercury (MeHg) is a well-known environmental neurotoxicant that causes severe brain disorders such as Minamata disease. Although some patients with Minamata disease develop olfactory dysfunction, the underlying pathomechanism is largely unknown. We examined the effects of MeHg on the olfactory system using a model of MeHg poisoning in which mice were administered 30 ppm MeHg in drinking water for 8 weeks. Mice exposed to MeHg displayed significant mercury accumulation in the olfactory pathway, including the nasal mucosa, olfactory bulb, and olfactory cortex. The olfactory epithelium was partially atrophied, and olfactory sensory neurons were diminished. The olfactory bulb exhibited an increase in apoptotic cells, hypertrophic astrocytes, and amoeboid microglia, mainly in the granular cell layer. Neuronal cell death was observed in the olfactory cortex, particularly in the ventral tenia tecta. Neuronal cell death was also remarkable in higher-order areas such as the orbitofrontal cortex. Correlation analysis showed that neuronal loss in the olfactory cortex was strongly correlated with the plasma mercury concentration. Our results indicate that MeHg is an olfactory toxicant that damages the central regions involved in odor perception. The model described herein is useful for analyzing the mechanisms and treatments of olfactory dysfunction in MeHg-intoxicated patients.
Serum microRNA profile enables preoperative diagnosis of uterine leiomyosarcoma
Uterine leiomyosarcoma (ULMS) is the major subtype of uterine sarcoma (US) and contributes to uterine cancer deaths. Although preoperative diagnosis of US remains challenging, frequent application of laparoscopic surgery for benign uterine leiomyomas (ULM) requires precise exclusion of US. MicroRNAs are stably present in the bloodstream, and the application of circulating miRNAs as disease biomarkers has been recognized. In the present study, we aimed to identify diagnostic biomarkers for distinguishing US from ULM by focusing on circulating miRNAs. All serum samples were collected preoperatively between 2009 and 2017, and all cases were histopathologically diagnosed. Whole miRNA profiles were obtained using a miRNA microarray. By analyzing expression levels of the miRNAs, candidate miRNAs were selected based on diagnostic performance in discriminating US from ULM, and a diagnostic model was then constructed. A total of 90 serum samples were analyzed, and clustering analyses revealed that the profiles of ULMS were distinct from those of controls. Based on leave‐one‐out cross‐validation, seven miRNAs were selected as biomarker candidates. Based on model construction, the optimal model consisted of two miRNAs (miR‐1246 and miR‐191‐5p), with an area under the receiver operating characteristic curve (AUC) for identifying ULMS of 0.97 (95% confidence interval [CI], 0.91‐1.00). In contrast, serum lactate dehydrogenase had an AUC of only 0.64 (95% CI, 0.34‐0.94). Seven serum miRNAs with high diagnostic performance for preoperative US screening were detected, and a promising diagnostic model for ULMS was generated. Whole circulating miRNA profiles in uterine sarcoma patient serum are analyzed. The result demonstrates feasibility for application as a novel preoperative biomarker.
Educational benefits for nurses and nursing students of the dementia supporter training program in Japan
In Japan, which is thought to be a rapidly growing super-aging society, a national campaign named \"the Dementia Supporter Caravan\" has been deployed. The aim of this study was to assess the educational benefits of the dementia supporter training program for nurses and nursing students. We conducted dementia supporter training, and measured knowledge and attitudes regarding people with dementia as educational benefits pre- and post-training. Data sets of 134 nursing students and 63 nurses were analyzed. The results indicated that the two groups gained knowledge, understanding, and the confidence to care for people with dementia after attending the dementia supporter training program. Moreover, the two groups derived different benefits from the program. Nursing students gained substantial knowledge and learnt the importance of early detection and treatment, to levels similar to those of nurses prior to training. The training program reduced the difficulties of nurses to interact with and care for people with dementia. We can conclude that the dementia supporter training program has considerable educational benefits for nurses and nursing students.
Overexpression of Lysophosphatidylcholine Acyltransferase 1 and Concomitant Lipid Alterations in Gastric Cancer
Background The involvement of lipids in carcinogenic and developmental processes has been reported in some malignancies, but their roles in gastric cancer remain to be analyzed. In this study, we compared the lipid content of gastric cancer tissue and adjacent nonneoplastic mucosa using imaging mass spectrometry. Methods Mass spectra were acquired from 12 sections of human gastric cancer tissue and adjacent nonneoplastic mucosa using a matrix-assisted laser desorption-ionization time-of-flight tandem mass spectrometry type mass spectrometer equipped with a 355 nm Nd:YAG laser. Protein expression of lysophosphatidylcholine acyltransferase 1 (LPCAT1), which converts lysophosphatidylcholine (LPC) to phosphatidylcholine (PC) in the presence of acyl-CoA in Lands’ cycle, was immunohistochemically analyzed in 182 gastric cancer specimens. Results The averaged mass spectra from the cancer tissue and nonneoplastic mucosa were identical. Most of the signals that differed between cancer tissue and nonneoplastic mucosa corresponded to phospholipids, the majority of which were PC and LPC. Two signals, m/z 798.5 and 496.3, were higher and lower, respectively, in cancer tissues, predominantly in differentiated adenocarcinoma. A database search enabled identification of the ions at m/z 798.5 and m/z 496.3 as potassium-adducted PC (16:0/18:1) and proton-adducted LPC (16:0), respectively. Immunohistochemical analysis revealed that LPCAT1 was highly expressed in cancer lesions compared to nonneoplastic mucosa, predominantly in differentiated adenocarcinoma. LPCAT1 expression levels correlated positively with tumor differentiation and negatively with tumor depth, lymph node metastasis, and tumor stage. Conclusions Overexpressed LPCAT1 protein in gastric mucosa appears to play important roles in the tumorigenic process of gastric cancer by converting LPC to PC.
Therapeutic potential of 4-phenylbutyric acid against methylmercury-induced neuronal cell death in mice
Methylmercury (MeHg) is an environmental neurotoxin that induces damage to the central nervous system and is the causative agent in Minamata disease. The mechanisms underlying MeHg neurotoxicity remain largely unknown, and there is a need for effective therapeutic agents, such as those that target MeHg-induced endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), which is activated as a defense mechanism. We investigated whether intraperitoneal administration of the chemical chaperone, 4-phenylbutyric acid (4-PBA), at 120 mg/kg/day can alleviate neurotoxicity in the brains of mice administered 50 ppm MeHg in drinking water for 5 weeks. 4-PBA significantly reduced MeHg-induced ER stress, neuronal apoptosis, and neurological symptoms. Furthermore, 4-PBA was effective even when administered 2 weeks after the initiation of exposure to 30 ppm MeHg in drinking water. Our results strongly indicate that ER stress and the UPR are key processes involved in MeHg toxicity, and that 4-PBA is a novel therapeutic candidate for MeHg-induced neurotoxicity.
Methylmercury, an environmental electrophile capable of activation and disruption of the Akt/CREB/Bcl-2 signal transduction pathway in SH-SY5Y cells
Methylmercury (MeHg) modifies cellular proteins via their thiol groups in a process referred to as “ S -mercuration”, potentially resulting in modulation of the cellular signal transduction pathway. We examined whether low-dose MeHg could affect Akt signaling involved in cell survival. Exposure of human neuroblastoma SH-SY5Y cells of up to 2 μM MeHg phosphorylated Akt and its downstream signal molecule CREB, presumably due to inactivation of PTEN through S -mercuration. As a result, the anti-apoptotic protein Bcl-2 was up-regulated by MeHg. The activation of Akt/CREB/Bcl-2 signaling mediated by MeHg was, at least in part, linked to cellular defence because either pretreatment with wortmannin to block PI3K/Akt signaling or knockdown of Bcl-2 enhanced MeHg-mediated cytotoxicity. In contrast, increasing concentrations of MeHg disrupted Akt/CREB/Bcl-2 signaling. This phenomenon was attributed to S -mercuration of CREB through Cys286 rather than Akt. These results suggest that although MeHg is an apoptosis-inducing toxicant, this environmental electrophile is able to activate the cell survival signal transduction pathway at lower concentrations prior to apoptotic cell death.
Regulation of the unfolded protein response via S-nitrosylation of sensors of endoplasmic reticulum stress
Protein S -nitrosylation modulates important cellular processes, including neurotransmission, vasodilation, proliferation and apoptosis in various cell types. We have previously reported that protein disulfide isomerase (PDI) is S -nitrosylated in brains of patients with sporadic neurodegenerative diseases. This modification inhibits PDI enzymatic activity and consequently leads to the accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) lumen. Here, we describe S -nitrosylation of additional ER pathways that affect the unfolded protein response (UPR) in cell-based models of Parkinson’s disease (PD). We demonstrate that nitric oxide (NO) can S -nitrosylate the ER stress sensors IRE1α and PERK. While S -nitrosylation of IRE1α inhibited its ribonuclease activity, S -nitrosylation of PERK activated its kinase activity and downstream phosphorylation/inactivation or eIF2α. Site-directed mutagenesis of IRE1α(Cys931) prevented S -nitrosylation and inhibition of its ribonuclease activity, indicating that Cys931 is the predominant site of S -nitrosylation. Importantly, cells overexpressing mutant IRE1α(C931S) were resistant to NO-induced damage. Our findings show that nitrosative stress leads to dysfunctional ER stress signaling, thus contributing to neuronal cell death.
Smoking Rates and Number of Cigarettes Smoked per Day in Schizophrenia: A Large Cohort Meta-Analysis in a Japanese Population
Cigarette smoking is consistently more common among schizophrenia patients than the general population worldwide; however, the findings of studies in Japan are inconsistent. Recently, the smoking rate has gradually decreased among the general population. We performed a meta-analysis of smoking status in a large Japanese cohort of (1) 1845 schizophrenia patients and 196845 general population and (2) 842 schizophrenia patients and 766 psychiatrically healthy controls from 12 studies over a 25-year period, including 301 patients and 131 controls from our study. In our case-control sample, schizophrenia patients had a significantly higher smoking rate than healthy controls (P=.031). The proportion of heavy smokers (P=.027) and the number of cigarettes smoked per day (P=8.20×10-3) were significantly higher among schizophrenia patients than healthy controls. For the smokers in the schizophrenia group, atypical antipsychotics dosage was positively correlated with cigarettes per day (P=1.00×10-3). A meta-analysis found that schizophrenia patients had a higher smoking rate than the general population for both men (OR=1.53, P=.035; schizophrenia patients, 52.9%; general population, 40.1%) and women (OR=2.40, P=1.08×10-5; schizophrenia patients, 24.4%; general population, 11.8%). In addition, male schizophrenia patients had a higher smoking rate than male healthy controls (OR=2.84, P=9.48×10-3; schizophrenia patients, 53.6%; healthy controls, 32.9%), but the difference was not significant for women (OR=1.36, P=.53; schizophrenia patients, 17.0%; healthy controls,14.1%). Among both males and females, schizophrenia patients had a higher smoking rate than both the general population (OR=1.88, P=2.60×10-5) and healthy controls (OR=2.05, P=.018). These rates were not affected by the patients' recruitment year (P>.05). The cigarettes per day values of schizophrenia patients and the general population were 22.0 and 18.8, respectively. Schizophrenia patients are approximately 2 times more likely to smoke than the general population and healthy controls based on data collected over a decade in Japan.