61 research outputs found

    Role of Secondary Organic Matter on Soot Particle Toxicity in Reconstituted Human Bronchial Epithelia Exposed at the Air-Liquid Interface.

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    Secondary organic matter (SOM) formed from gaseous precursors constitutes a major mass fraction of fine particulate matter. However, there is only limited evidence on its toxicological impact. In this study, air-liquid interface cultures of human bronchial epithelia were exposed to different series of fresh and aged soot particles generated by a miniCAST burner combined with a micro smog chamber (MSC). Soot cores with geometric mean mobility diameters of 30 and 90 nm were coated with increasing amounts of SOM, generated from the photo-oxidation of mesitylene and ozonolysis of α-pinene. At 24 h after exposure, the release of lactate dehydrogenase (LDH), indicating cell membrane damage, was measured and proteome analysis, i.e. the release of 102 cytokines and chemokines to assess the inflammatory response, was performed. The data indicate that the presence of the SOM coating and its bioavailability play an important role in cytotoxicity. In particular, LDH release increased with increasing SOM mass/total particle mass ratio, but only when SOM had condensed on the outer surface of the soot cores. Proteome analysis provided further evidence for substantial interference of coated particles with essential properties of the respiratory epithelium as a barrier as well as affecting cell remodeling and inflammatory activity

    Mitochondria-Associated MicroRNAs in Rat Hippocampus Following Traumatic Brain Injury

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    Traumatic brain injury (TBI) is a major cause of death and disability. However, the molecular events contributing to the pathogenesis are not well understood. Mitochondria serve as the powerhouse of cells, respond to cellular demands and stressors, and play an essential role in cell signaling, differentiation, and survival. There is clear evidence of compromised mitochondrial function following TBI; however, the underlying mechanisms and consequences are not clear. MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression post-transcriptionally, and function as important mediators of neuronal development, synaptic plasticity, and neurodegeneration. Several miRNAs show altered expression following TBI; however, the relevance of mitochondria in these pathways is unknown. Here, we present evidence supporting the association of miRNA with hippocampal mitochondria, as well as changes in mitochondria-associated miRNA expression following a controlled cortical impact (CCI) injury in rats. Specifically, we found that the miRNA processing proteins Argonaute (AGO) and Dicer are present in mitochondria fractions from uninjured rat hippocampus, and immunoprecipitation of AGO associated miRNA from mitochondria suggests the presence of functional RNA-induced silencing complexes. Interestingly, RT-qPCR miRNA array studies revealed that a subset of miRNA is enriched in mitochondria relative to cytoplasm. At 12h following CCI, several miRNAs are significantly altered in hippocampal mitochondria and cytoplasm. In addition, levels of miR-155 and miR-223, both of which play a role in inflammatory processes, are significantly elevated in both cytoplasm and mitochondria. We propose that mitochondria-associated miRNAs may play an important role in regulating the response to TBI

    Haemolysis during Sample Preparation Alters microRNA Content of Plasma

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    The presence of cell-free microRNAs (miRNAs) has been detected in a range of body fluids. The miRNA content of plasma/serum in particular has been proposed as a potential source of novel biomarkers for a number of diseases. Nevertheless, the quantification of miRNAs from plasma or serum is made difficult due to inefficient isolation and lack of consensus regarding the optimal reference miRNA. The effect of haemolysis on the quantification and normalisation of miRNAs in plasma has not been investigated in great detail. We found that levels of miR-16, a commonly used reference gene, showed little variation when measured in plasma samples from healthy volunteers or patients with malignant mesothelioma or coronary artery disease. Including samples with evidence of haemolysis led to variation in miR-16 levels and consequently decreased its ability to serve as a reference. The levels of miR-16 and miR-451, both present in significant levels in red blood cells, were proportional to the degree of haemolysis. Measurements of the level of these miRNAs in whole blood, plasma, red blood cells and peripheral blood mononuclear cells revealed that the miRNA content of red blood cells represents the major source of variation in miR-16 and miR-451 levels measured in plasma. Adding lysed red blood cells to non-haemolysed plasma allowed a cut-off level of free haemoglobin to be determined, below which miR-16 and miR-451 levels displayed little variation between individuals. In conclusion, increases in plasma miR-16 and miR-451 are caused by haemolysis. In the absence of haemolysis the levels of both miR-16 and miR-451 are sufficiently constant to serve as normalisers

    Psychosocial functioning of young adolescent and adult survivors of childhood cancer

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    Goals of work: The present study aimed to assess the psychosocial well-being of Greek adolescent and young adult survivors of childhood cancer and, in particular, self-esteem, anxiety, coping strategies, and social functioning. Patients and methods: The sample comprised 103 Greek childhood cancer survivors and 135 healthy controls. The Battle Culture-free Self-esteem Inventory (BCSEI), the Spielberger State-Trait Anxiety Inventory (STAI), the Lazarus and Folkman Ways of Coping, and 36-item short-form instruments were used along with The Questionnaire for the Quality of Life. Main results: Survivors scored higher than controls on all STAI subscales, but on State, the difference was statistically significant only for female adults, while on the Trait subscale, for the entire group. Survivors scored lower on Personal and higher on Lie subscale of BCSEI, by comparison to controls. When coping with stressful events, the use of self-blame strategies and wishful thinking were more frequent among controls, while distancing strategies more common among survivors. Conclusions: The long-term psychological functioning of Greek survivors of childhood cancer is satisfactory, with emotional difficulties, such as increased anxiety and lower self-esteem, receding over time. Survivors experience personal growth and mature through trauma as they develop a positive view of the impact that the cancer experience has upon their life. © 2007 Springer-Verlag

    Quality of Life of Adolescent and Young Adult Survivors of Childhood Cancer

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    The purpose of this study was to assess the quality of life of Greek survivors of childhood cancer by addressing the physical, psychological, spiritual, and social dimensions of their functioning. The SF-36 Health Survey and the Quality of Life Questionnaire, which was designed for this study, were used. Survivors' scores on most subscales of SF-36 were similar to those of controls, despite some difficulties in their daily activities. They perceived self as more susceptible to health problems, but also more mature and grounded. Generally, they seem to adapt well and focus on the positive aspects of their cancer experience, which enhances the meaning and quality of their life. © 2009 Elsevier Inc. All rights reserved

    The role of miRNAs in endometrial cancer

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    miRNAs are small noncoding RNAs that regulate gene expression at the post-transcriptional level. Since their discovery, miRNAs have been associated with every cell function including malignant transformation and metastasis. Endometrial cancer is the most common gynecologic malignancy. However, improvement should be made in interobserver agreement on histological typing and individualized therapeutic approaches. This article summarizes the role of miRNAs in endometrial cancer pathogenesis and treatment. © 2015 Future Medicine Ltd

    Epigenetics in gastrointestinal stromal tumors: Clinical implications and potential therapeutic perspectives

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    Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal neoplasms affecting the gastrointestinal tract. Activating mutations in either the KIT or PDGFRa gene are the principal oncogenic triggers with the former accounting for more than 80 % of cases. In the small subset of GIST that are wild type for both the aforementioned changes, other germline or somatic mutations have been identified. GIST exhibit a highly variable clinical behavior and the main prognostic determinants are tumor size, mitotic rate, and location. It is, however, strongly believed that, beyond classic genetics, additional epigenetic phenomena such as DNA hypomethylation and hypermethylation, microRNA alterations, and chromatin modifications underlie GIST tumorigenesis and influence the clinical course and response to standard treatment. This review aims to illuminate current advances in terms of epigenetics in GIST, as well as possible implications in prognosis and therapeutics. © 2013 Springer Science+Business Media New York
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