40 research outputs found

    MAPK-Activated Protein Kinase 2 Is Required for Mouse Meiotic Spindle Assembly and Kinetochore-Microtubule Attachment

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    MAPK-activated protein kinase 2 (MK2), a direct substrate of p38 MAPK, plays key roles in multiple physiological functions in mitosis. Here, we show for the first time the unique distribution pattern of MK2 in meiosis. Phospho-MK2 was localized on bipolar spindle minus ends and along the interstitial axes of homologous chromosomes extending over centromere regions and arm regions at metaphase of first meiosis (MI stage) in mouse oocytes. At metaphase of second meiosis (MII stage), p-MK2 was localized on the bipolar spindle minus ends and at the inner centromere region of sister chromatids as dots. Knockdown or inhibition of MK2 resulted in spindle defects. Spindles were surrounded by irregular nondisjunction chromosomes, which were arranged in an amphitelic or syntelic/monotelic manner, or chromosomes detached from the spindles. Kinetochore–microtubule attachments were impaired in MK2-deficient oocytes because spindle microtubules became unstable in response to cold treatment. In addition, homologous chromosome segregation and meiosis progression were inhibited in these oocytes. Our data suggest that MK2 may be essential for functional meiotic bipolar spindle formation, chromosome segregation and proper kinetochore–microtubule attachments

    CD1d-Expressing Breast Cancer Cells Modulate NKT Cell-Mediated Antitumor Immunity in a Murine Model of Breast Cancer Metastasis

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    Tumor tolerance and immune suppression remain formidable obstacles to the efficacy of immunotherapies that harness the immune system to eradicate breast cancer. A novel syngeneic mouse model of breast cancer metastasis was developed in our lab to investigate mechanisms of immune regulation of breast cancer. Comparative analysis of low-metastatic vs. highly metastatic tumor cells isolated from these mice revealed several important genetic alterations related to immune control of cancer, including a significant downregulation of cd1d1 in the highly metastatic tumor cells. The cd1d1 gene in mice encodes the MHC class I-like molecule CD1d, which presents glycolipid antigens to a specialized subset of T cells known as natural killer T (NKT) cells. We hypothesize that breast cancer cells, through downregulation of CD1d and subsequent evasion of NKT-mediated antitumor immunity, gain increased potential for metastatic tumor progression.In this study, we demonstrate in a mouse model of breast cancer metastasis that tumor downregulation of CD1d inhibits iNKT-mediated antitumor immunity and promotes metastatic breast cancer progression in a CD1d-dependent manner in vitro and in vivo. Using NKT-deficient transgenic mouse models, we demonstrate important differences between type I and type II NKT cells in their ability to regulate antitumor immunity of CD1d-expressing breast tumors.The results of this study emphasize the importance of determining the CD1d expression status of the tumor when tailoring NKT-based immunotherapies for the prevention and treatment of metastatic breast cancer

    Direct Injection of Functional Single-Domain Antibodies from E. coli into Human Cells

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    Intracellular proteins have a great potential as targets for therapeutic antibodies (Abs) but the plasma membrane prevents access to these antigens. Ab fragments and IgGs are selected and engineered in E. coli and this microorganism may be also an ideal vector for their intracellular delivery. In this work we demonstrate that single-domain Ab (sdAbs) can be engineered to be injected into human cells by E. coli bacteria carrying molecular syringes assembled by a type III protein secretion system (T3SS). The injected sdAbs accumulate in the cytoplasm of HeLa cells at levels ca. 105–106 molecules per cell and their functionality is shown by the isolation of sdAb-antigen complexes. Injection of sdAbs does not require bacterial invasion or the transfer of genetic material. These results are proof-of-principle for the capacity of E. coli bacteria to directly deliver intracellular sdAbs (intrabodies) into human cells for analytical and therapeutic purposes

    Development and Psychometric Properties of a New Questionnaire to Assess Mental Health and Concerning Behaviors in Children and Young People with Autism Spectrum Disorder (ASD):The Assessment of Concerning Behavior (ACB) Scale

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    Although 70% of autistic children and young people meet criteria for co-occurring psychiatric conditions, there are few screening measures specifically for autistic individuals. We describe the development and validation of the Assessment of Concerning Behavior (ACB), an instrument co-developed with the autistic community to assess mental health and problematic/risky behaviors. Items include descriptions to facilitate symptom recognition by autistic people, and carers/professionals. The ACB was completed by 255 parents, 149 autistic children and young people and 30 teachers. Internal consistency, stability and validity was assessed. The ACB parent-version fit a two-factor model (internalizing and externalizing problems) and showed adequate test–retest reliability, internal consistency and construct validity. The ACB is a promising new measure for research and clinical use in autism

    Associations of adult measures of childhood growth with breast cancer: findings from the British Women's Heart and Health Study.

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    Since the two components of adult height - leg length and trunk length - are poorly correlated with each other and appear to be influenced by different early life factors, examining their separate influence on breast cancer may provide additional insights into the mechanisms responsible for the positive association between adult height and breast cancer. In a cross-sectional study of 4286 women aged 60-79 years, in whom there were 170 cases of breast cancer, we found total height, leg length and trunk length were all modestly positively and linearly associated with breast cancer. The magnitudes of the associations of leg and trunk length were similar: fully adjusted odds ratio (95% confidence interval) of breast cancer for a one standard deviation (s.d.) increase in leg length 1.17 (0.98, 1.39) and for a 1 s.d. increase in trunk length 1.19 (0.99, 1.41). Self-reported birth weight (available on 33% of the sample) was positively and linearly associated with breast cancer: fully adjusted odds ratio of breast cancer for a 1 s.d. increase in birth weight 1.30 (0.93, 1.80). These associations were all independent of each other and other potential confounding factors and are likely to reflect different mechanisms by which factors operating prenatally and prepubertally influence breast cancer risk

    Stacking Functions: Identifying Motivational Frames Guiding Urban Agriculture Organizations and Businesses in the United States and Canada

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    While a growing body of scholarship identifies urban agriculture\u27s broad suite of benefits and drivers, it remains unclear how motivations to engage in urban agriculture (UA) interrelate or how they differ across cities and types of organizations. In this paper, we draw on survey responses collected from more than 250 UA organizations and businesses from 84 cities across the United States and Canada. Synthesizing the results of our quantitative analysis of responses (including principal components analysis), qualitative analysis of textual data excerpted from open-ended responses, and a review of existing literature, we describe six motivational frames that appear to guide organizations and businesses in their UA practice: Entrepreneurial, Sustainable Development, Educational, Eco-Centric, DIY Secessionist, and Radical. Identifying how practitioners stack functions and frame their work is a first step in helping to differentiate the diverse and often contradictory efforts transforming urban food environments. We demonstrate that a wide range of objectives impact how urban agriculturalists practice UA and that political orientations and discourses differ across geographies, organizational type and size, and funding regime. These six paradigms provide a basic framework for understanding UA that can guide more in-depth studies of the gap between intentions and outcomes, while helping link historically and geographically specific insights to wider social and political economic processes
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