301 research outputs found

    Intracranial extension of adenoid cystic carcinoma: potential involvement of EphA2 expression and epithelial-mesenchymal transition in tumor metastasis: a case report

    Get PDF
    BACKGROUND: Adenoid cystic carcinoma is a malignant epithelial tumor derived from salivary glands and tends to invade the surrounding structures including nervous system. We present a case of adenoid cystic carcinoma with intracranial extension and propose a novel molecular mechanism of adenoid cystic carcinoma metastasis. CASE PRESENTATION: A 29-year-old Japanese male presented with left trigeminal nerve disturbance. Neuroimaging revealed a tumor located at the right middle cranial and infratemporal fossa. The tumor was removed via a subtemporal extradural and infratemporal fossa approach and histologically diagnosed as adenoid cystic carcinoma. Radiological and operative findings confirmed a perineural spread of the tumor along the mandibular nerve. Immunohistochemical analyses of molecular consequences in this case were performed for better understanding of the biological processes associated with adenoid cystic carcinoma metastasis. First, the neoplastic cells were not immunoreactive for E-cadherin, an epithelial marker, but for vimentin, a mesenchymal marker, suggesting changes in cell phenotype from epithelial to mesenchymal states. Correspondingly, immunoreactivity of transcriptional factors, such as Slug, Twist, matrix metalloproteinase-2 and -9, which are involved in epithelial–mesenchymal transition, were observed. Second, elevated expression of EphA2 receptor, not ephrin-A1, was notable in the neoplastic cells, suggesting morphological changes reminiscent of epithelial–mesenchymal transition and ligand-independent promotion of tumor cell migration and invasion. CONCLUSIONS: We report a case of adenoid cystic carcinoma with perineural spread and provide the first published evidence that EphA2 expression without ephrin-A1 and epithelial–mesenchymal transition might play important roles in adenoid cystic carcinoma progression

    Applications for Induced Pluripotent Stem Cells in Disease Modelling and Drug Development for Heart Diseases

    Get PDF
    Induced pluripotent stem cells (iPSCs) are derived from reprogrammed somatic cells by the introduction of defined transcription factors. They are characterised by a capacity for self-renewal and pluripotency. Human (h)iPSCs are expected to be used extensively for disease modelling, drug screening and regenerative medicine. Obtaining cardiac tissue from patients with mutations for genetic studies and functional analyses is a highly invasive procedure. In contrast, disease-specific hiPSCs are derived from the somatic cells of patients with specific genetic mutations responsible for disease phenotypes. These disease-specific hiPSCs are a better tool for studies of the pathophysiology and cellular responses to therapeutic agents. This article focuses on the current understanding, limitations and future direction of disease-specific hiPSC-derived cardiomyocytes for further applications

    Modeling of lung phenotype of Hermansky–Pudlak syndrome type I using patient-specific iPSCs

    Get PDF
    iPS細胞を用いてヘルマンスキー・パドラック症候群の肺病態の解析に成功 --研究が困難な遺伝性疾患の治療薬開発の足がかりに--. 京都大学プレスリリース. 2021-11-15.[Background] Somatic cells differentiated from patient-specific human induced pluripotent stem cells (iPSCs) could be a useful tool in human cell-based disease research. Hermansky–Pudlak syndrome (HPS) is an autosomal recessive genetic disorder characterized by oculocutaneous albinism and a platelet dysfunction. HPS patients often suffer from lethal HPS associated interstitial pneumonia (HPSIP). Lung transplantation has been the only treatment for HPSIP. Lysosome-related organelles are impaired in HPS, thereby disrupting alveolar type 2 (AT2) cells with lamellar bodies. HPSIP lungs are characterized by enlarged lamellar bodies. Despite species differences between human and mouse in HPSIP, most studies have been conducted in mice since culturing human AT2 cells is difficult. [Methods] We generated patient-specific iPSCs from patient-derived fibroblasts with the most common bi-allelic variant, c.1472_1487dup16, in HPS1 for modeling severe phenotypes of HPSIP. We then corrected the variant of patient-specific iPSCs using CRISPR-based microhomology-mediated end joining to obtain isogenic controls. The iPSCs were then differentiated into lung epithelial cells using two different lung organoid models, lung bud organoids (LBOs) and alveolar organoids (AOs), and explored the phenotypes contributing to the pathogenesis of HPSIP using transcriptomic and proteomic analyses. [Results] The LBOs derived from patient-specific iPSCs successfully recapitulated the abnormalities in morphology and size. Proteomic analysis of AOs involving iPSC-derived AT2 cells and primary lung fibroblasts revealed mitochondrial dysfunction in HPS1 patient-specific alveolar epithelial cells. Further, giant lamellar bodies were recapitulated in patient-specific AT2 cells. [Conclusions] The HPS1 patient-specific iPSCs and their gene-corrected counterparts generated in this study could be a new research tool for understanding the pathogenesis of HPSIP caused by HPS1 deficiency in humans

    Disease modeling of pulmonary fibrosis using human pluripotent stem cell-derived alveolar organoids

    Get PDF
    iPS細胞を用いて作製した肺胞オルガノイドで間質性肺炎の病態再現に成功 --治療満足度の低い間質性肺炎の治療薬開発に向けて前進--. 京都大学プレスリリース. 2021-11-19.Although alveolar epithelial cells play a critical role in the pathogenesis of pulmonary fibrosis, few practical in vitro models exist to study them. Here, we established a novel in vitro pulmonary fibrosis model using alveolar organoids consisting of human pluripotent stem cell-derived alveolar epithelial cells and primary human lung fibroblasts. In this human model, bleomycin treatment induced phenotypes such as epithelial cell-mediated fibroblast activation, cellular senescence, and presence of alveolar epithelial cells in abnormal differentiation states. Chemical screening performed to target these abnormalities showed that inhibition of ALK5 or blocking of integrin αVβ6 ameliorated the fibrogenic changes in the alveolar organoids. Furthermore, organoid contraction and extracellular matrix accumulation in the model recapitulated the pathological changes observed in pulmonary fibrosis. This human model may therefore accelerate the development of highly effective therapeutic agents for otherwise incurable pulmonary fibrosis by targeting alveolar epithelial cells and epithelial-mesenchymal interactions

    Prompt and Long-term Prophylactic Effect of Closed Loop Stimulation against Paroxysmal Atrial Fibrillation in a Patient with Sick Sinus Syndrome

    Get PDF
    A 72-year-old woman with sick sinus syndrome (SSS), who had frequent paroxysmal atrial fibrillations (PAfs) and normal cardiac function, was admitted to our hospital due to syncope. PAfs frequently occurred during the first week after DDD pacemaker implantation (PMI), with closed loop stimulation (CLS) rate-adaptive mode off, but were completely suppressed during the second week, with CLS on, and had been well-controlled over three years thereafter. However, PAfs occasionally occurred under intense sympathetic activity during 6 months after PMI as well, and were effectively terminated by disopyramide which had anticholinergic effect. Thus, the development and maintenance of PAf were thought to be associated with destabilized cardiac autonomic activities, that is, sympathetic and parasympathetic dominance, respectively. Additionally, heart rate variability analyses after implementation of CLS revealed the restoration of sympathetic and parasympathetic components. Accordingly, CLS mode was considered to play a critical role in preventing PAf by reflecting autonomic activity in heart rhythm in this SSS patient

    Is Pulse Pressure a Predictor of New-Onset Diabetes in High-Risk Hypertensive Patients?: A subanalysis of the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial

    Get PDF
    OBJECTIVE: Hypertensive patients have an increased risk of developing diabetes. Accumulating evidence suggests a close relation between metabolic disturbance and increased arterial stiffness. Here, we examined the association between pulse pressure and the risk of new-onset diabetes in high-risk Japanese hypertensive patients. RESEARCH DESIGN AND METHODS: The Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial examined the effects of candesartan and amlodipine on the incidence of cardiovascular events in 4, 728 high-risk Japanese hypertensive patients. In the present study, we analyzed the relationship between pulse pressure at baseline and new-onset diabetes in 2, 685 patients without diabetes at baseline (male 1, 471; mean age 63.7 years; mean BMI 24.8 kg/m(2)) as a subanalysis of the CASE-J trial. RESULTS: During 3.3 +/- 0.8 years of follow-up, 97 patients (3.6%) developed diabetes. In multiple Cox regression analysis, pulse pressure was an independent predictor for new-onset diabetes (hazard ratio [HR] per 1 SD increase 1.44 [95% CI 1.15-1.79]) as were male sex, BMI, and additional use of diuretics, whereas age and heart rate were not. Plots of HRs for new-onset diabetes considering both systolic and diastolic blood pressure (DBP) revealed that a higher pulse pressure with a lower DBP, indicating that the increased pulse pressure was largely due to increased arterial stiffness, was strongly associated with the risk of new-onset diabetes. CONCLUSIONS: Pulse pressure is an independent predictor of new-onset diabetes in high-risk Japanese hypertensive patients. Increased arterial stiffness may be involved in the development of diabetes
    corecore