708 research outputs found
IGF-1 increases invasive potential of MCF 7 breast cancer cells and induces activation of latent TGF-β1 resulting in epithelial to mesenchymal transition
<p>Abstract</p> <p>Introduction</p> <p>TGF-β signaling has been extensively studied in many developmental contexts, amongst which is its ability to induce epithelial to mesenchymal transitions (EMT). EMTs play crucial roles during embryonic development and have also come under intense scrutiny as a mechanism through which breast cancers progress to become metastatic. Interestingly, while the molecular hallmarks of EMT progression (loss of cell adhesion, nuclear localization of β-catenin) are straightforward, the cellular signaling cascades that result in an EMT are numerous and diverse. Furthermore, most studies describing the biological effects of TGF-β have been performed using high concentrations of active, soluble TGF-β, despite the fact that TGF-β is produced and secreted as a latent complex.</p> <p>Methods</p> <p>MCF-7 breast cancer cells treated with recombinant IGF-1 were assayed for metalloproteinase activity and invasiveness through a matrigel coated transwell invasion chamber. IGF-1 treatments were then followed by the addition of latent-TGF-β1 to determine if elevated levels of IGF-1 together with latent-TGF-β1 could cause EMT.</p> <p>Results</p> <p>Results showed that IGF-1 - a molecule known to be elevated in breast cancer is a regulator of matrix metalloproteinase activity (MMP) and the invasive potential of MCF-7 breast cancer cells. The effects of IGF-1 appear to be mediated through signals transduced via the PI3K and MAPK pathways. In addition, increased IGF-1, together with latent TGF-β1 and active MMPs result in EMT.</p> <p>Conclusions</p> <p>Taken together our data suggest a novel a link between IGF-1 levels, MMP activity, TGF-β signaling, and EMT in breast cancer cells.</p
Analysis of the MMP-dependent and independent functions of tissue inhibitor of metalloproteinase-2 on the invasiveness of breast cancer cells
Matrix metalloproteinases (MMPs) are secreted endopeptidases that play an essential role in remodeling the extracellular matrix (ECM). MMPs are primarily active during development, when the majority of ECM remodeling events occurs. In adults, elevated MMP activity has been observed in many pathological conditions such as cancer and osteoarthritis. The proteolytic activity of MMPs is controlled by their natural inhibitors - the tissue inhibitor of metalloproteinases (TIMPs). In addition to blocking MMP-mediated proteolysis, TIMPs have a number of MMP-independent functions including binding to cell surface proteins thereby stimulating signaling cascades. TIMP-2, the most studied member of the family, can both inhibit and activate MMPs directly, as well as inhibit MMP activity indirectly by upregulating expression of RECK, a membrane anchored MMP regulator. While TIMP-2 has been shown to play important roles in breast cancer, we describe how the MMP-independent effects of TIMP-2 can modulate the invasiveness of MCF-7, T47D and MDA-MB-231 breast cancer cells. Using an ALA + TIMP-2 mutant which is devoid of MMP inhibition, but still capable of initiating specific cell signaling cascades, we show that TIMP-2 can differentially affect MMP activity and cellular invasiveness in both an MMP dependent and independent manner. More specifically, MMP activity and invasiveness is increased with the addition of exogenous TIMP-2 in poorly invasive cell lines whereas it is decreased in highly invasive cells lines (MDA-MB-231). Conversely, the addition of ALA + TIMP-2 resulted in decreased invasiveness regardless of cell line. Š The International CCN Society 2012
PEX11β induces peroxisomal gene expression and alters peroxisome number during early Xenopus laevis development
<p>Abstract</p> <p>Background</p> <p>Peroxisomes are organelles whose roles in fatty acid metabolism and reactive oxygen species elimination have contributed much attention in understanding their origin and biogenesis. Many studies have shown that <it>de novo </it>peroxisome biogenesis is an important regulatory process, while yeast studies suggest that total peroxisome numbers are in part regulated by proteins such as Pex11, which can facilitate the division of existing peroxisomes. Although <it>de novo </it>biogenesis and divisions are likely important mechanisms, the regulation of peroxisome numbers during embryonic development is poorly understood. Peroxisome number and function are particularly crucial in oviparous animals such as frogs where large embryonic yolk and fatty acid stores must be quickly metabolized, and resulting reactive oxygen species eliminated. Here we elucidate the role of Pex11β in regulating peroxisomal gene expression and number in <it>Xenopus laevis </it>embryogenesis.</p> <p>Results</p> <p>Microinjecting haemagglutinin (HA) tagged Pex11β in early embryos resulted in increased RNA levels for peroxisome related genes PMP70 and catalase at developmental stages 10 and 20, versus uninjected embryos. Catalase and PMP70 proteins were found in punctate structures at stage 20 in control embryos, whereas the injection of ectopic HA-Pex11β induced their earlier localization in punctate structures at stage 10. Furthermore, the peroxisomal marker GFP-SKL, which was found localized as peroxisome-like structures at stage 20, was similarly found at stage 10 when co-microinjected with HA-Pex11β.</p> <p>Conclusions</p> <p>Overexpressed Pex11β altered peroxisomal gene levels and induced the early formation of peroxisomes-like structures during development, both of which demonstrate that Pex11β may be a key regulator of peroxisome number in early Xenopus embryos.</p
Prospectus, September 17, 1980
CATCHY SLOGAN BRINGS OUT RECORD NUMBER OF VOTES; Parkland People; Parkland English teacher speaks to PCF\u27ers on Self-Image ; Head of Placement Counseling will help employment seekers; PACT offers program; Blood drive to be at PC; Attention Accounting students; Classifieds; PC Datebook; Record number of voters turn out to elect new Student Senators; Letters to the editor: Student disappointed; Long distance marriage works-- Susan Kelley sets an example; Women\u27s Program offers self-series; Jackson Browne performance: unforgettable; Molly Hatchet\u27s cuts are consistently impressive and original; Bowen: Radio won\u27t roll over and die; Two kinds of clouds cause false tornado reports; Team shirts or fan shirts-- T-shirts make us all more human; P.C. Women\u27s Program offers workshops; Sign up for insurance this week; PACT offers program; Science You Can See: Cosmos Is Coming!!; Parkland College Cross Country Schedule 1980; 100 cash awards offered young people; Local members attend convention; Golf team disappointing in PC Invitational; Fast Freddy won\u27t contend Jimmy The Greek this week; Volleyball team opens season; Fast Freddy Contest; Bench Warmer: Faculty out to upset softball teamhttps://spark.parkland.edu/prospectus_1980/1021/thumbnail.jp
Identification and proteomic profiling of exosomes in human cerebrospinal fluid
<p>Abstract</p> <p>Background</p> <p>Exosomes are released from multiple cell types, contain protein and RNA species, and have been exploited as a novel reservoir for disease biomarker discovery. They can transfer information between cells and may cause pathology, for example, a role for exosomes has been proposed in the pathophysiology of Alzheimer's disease. Although studied in several biofluids, exosomes have not been extensively studied in the cerebrospinal fluid (CSF) from humans. The objective of this study was to determine: 1) whether human CSF contains exosomes and 2) the variability in exosomal protein content across individuals.</p> <p>Methods</p> <p>CSF was collected from 5 study participants undergoing thoraco-abdominal aortic aneurysm repair (around 200 - 500 ml per participant) and low-density membrane vesicles were concentrated by ultracentrifugation. The presence of exosomes was determined by western blot for marker proteins, isopycnic centrifugation on a sucrose step gradient and transmission electron microscopy with immuno-labelling. Whole protein profiling was performed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR).</p> <p>Results</p> <p>Flotillin 1 and tumor susceptibility gene 101 (TSG101), two exosomal marker proteins, were identified in the ultracentrifugation pellet using western blot. These markers localized to a density consistent with exosomes following isopycnic centrifugation. Transmission electron microscopy visualized structures consistent with exosomes in size and appearance that labelled positive for flotillin 1. Therefore, the pellet that resulted from ultracentrifugation of human CSF contained exosomes. FT-ICR profiling of this pellet was performed and 84-161 ions were detected per study participant. Around one third of these ions were only present in a single study participant and one third were detected in all five. With regard to ion quantity, the median coefficient of variation was 81% for ions detected in two or more samples.</p> <p>Conclusions</p> <p>Exosomes were identified in human CSF and their proteome is a potential new reservoir for biomarker discovery in neurological disorders such as Alzheimer's disease. However, techniques used to concentrate exosomes from CSF need refinement to reduce variability. In this study we used relatively large starting volumes of human CSF, future studies will focus on exosome isolation from smaller 'real life' clinical samples; a key challenge in the development of exosomes as translational tools.</p
Epidemiological, clinical and genetic aspects of adult onset isolated focal dystonia in Ireland
Background: Adult onset idiopathic isolated focal dystonia presents with a number of phenotypes. Reported prevalence rates vary considerably; well-characterized cohorts are important to our understanding of this disorder.
Aim: To perform a nationwide epidemiological study of adult onset idiopathic isolated focal dystonia in the Republic of Ireland.
Methods: Patients with adult onset idiopathic isolated focal dystonia were recruited from multiple sources. Diagnosis was based on assessment by a neurologist with an expertise in movement disorders. When consent was obtained, a number of clinical features including family history were assessed.
Results: On the prevalence date there were 592 individuals in Ireland with adult onset idiopathic isolated focal dystonia, a point prevalence of 17.8 per 100 000 (95% confidence interval 16.4-19.2). Phenotype numbers were cervical dystonia 410 (69.2%), blepharospasm 102 (17.2%), focal hand dystonia 39 (6.6%), spasmodic dysphonia 18 (3.0%), musician\u27s dystonia 17 (2.9%) and oromandibular dystonia six (1.0%). Sixty-two (16.5%) of 375 consenting index cases had a relative with clinically confirmed adult onset idiopathic isolated focal dystonia (18 multiplex and 24 duplex families). Marked variations in the proportions of patients with tremor, segmental spread, sensory tricks, pain and psychiatric symptoms by phenotype were documented.
Conclusions: The prevalence of adult onset idiopathic isolated focal dystonia in Ireland is higher than that recorded in many similar service-based epidemiological studies but is still likely to be an underestimate. The low proportion of individuals with blepharospasm may reflect reduced environmental exposure to sunlight in Ireland. This study will serve as a resource for international comparative studies of environmental and genetic factors in the pathogenesis of the disorder
CDR3 Variants of the TXB2 Shuttle with Increased TfR1 Association Rate and Enhanced Brain Penetration
âIt Happens to Girls All the Timeâ: Examining Sexual Assault Survivorsâ Reasons for Not Using Campus Supports
Sexual assault is a prevalent problem in higher education, and despite the increasing availability of formal supports on college campuses, few sexual assault survivors use them. Experiencing sexual assault can have devastating consequences on survivorsâ psychological and educational wellbeing, which may intensify if survivors do not receive adequate care. Drawing from existing theoretical frameworks and empirical research, this study used a mixed methodological approach to examine why survivors did not use three key campus supportsâthe Title IX Office, the sexual assault center, and housing staffâand if these reasons differed across the three supports. Using data from 284 women who experienced sexual assault in college, our qualitative findings identified four overarching themes, including logistical issues (e.g., lacking time and knowledge), feelings, beliefs, and responses that made it seem unacceptable to use campus supports, judgments about the appropriateness of the support, and alternative methods of coping. Quantitative findings revealed that survivorsâ reasons for not seeking help differed across supports. Collectively, our findings suggest that community norms and institutional policies can make it challenging for survivors to use campus supports. We propose several suggestions for institutional change (e.g., taking a stronger stance against âless seriousâ forms of sexual assault, reducing a quasiâcriminal justice approach to investigation and adjudication, limiting mandated reporting).HighlightsIdentifies reasons why college students who experience sexual assault do not use formal sources of support on campus.Examines how reasons for not using formal supports differ across sources of support: Title IX Office, sexual assault center, and housing staff.Provides an inâdepth, contextual understanding of sexual assault survivorsâ use and avoidance of campus supports in the wake of substantial policy change.Contributes recommendations for institutional policy and practice based on findings, including taking a stronger stance against âless seriousâ forms of sexual assault, reducing a quasiâcriminal justice approach to investigation and adjudication, and limiting mandated reporting.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136479/1/ajcp12126.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136479/2/ajcp12126_am.pd
Argonia Cup senior capstone competition: Final presentation
The goal of this project was to design and develop a rocket that could get a payload golf ball to at least 8,000 AGL and then return it as close to the X on the ground as possible. In order to achieve this goal, we decided to design an integrated deployable quadcopter UAC that would deploy at apogee and then autonomously fly itself back to the designated target location. This concept has never been achieved before and therefore we wanted to be the first to successfully complete the mission. Despite our work and determination we were unsuccessful of a true recovery however we believe we have made the most progress and had the most success of anyone attempting such a feat at the high-powered rocketry level
Rocket launched autonomous quadcopter final report
The goal of this project was to design and develop a rocket that could get a payload golf ball to at least 8,000 AGL and then return it as close to the X on the ground as possible. In order to achieve this goal, we decided to design an integrated deployable quadcopter UAC that would deploy at apogee and then autonomously fly itself back to the designated target location. This concept has never been achieved before and therefore we wanted to be the first to successfully complete the mission. Despite our work and determination we were unsuccessful of a true recovery however we believe we have made the most progress and had the most success of anyone attempting such a feat at the high-powered rocketry level
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