250 research outputs found

    Synthesis and structure activity relationships of DCLK1 kinase inhibitors based on a 5,11-dihydro-6H-benzo[e]pyrimido[5,4-b] [1,4]diazepin-6-one scaffold

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    Doublecortin-like kinase 1 (DCLK1) is a serine/threonine kinase that is overexpressed in gastrointestinal cancers, including esophageal, gastric, colorectal, and pancreatic cancers. DCLK1 is also used as a marker of tuft cells, which regulate type II immunity in the gut. However, the substrates and functions of DCLK1 are understudied. We recently described the first selective DCLK1/2 inhibitor, DCLK1-IN-1, developed to aid the functional characterization of this important kinase. Here we describe the synthesis and structure-activity relationships of 5,11-dihydro-6H-benzo[e]pyrimido[5,4-b][1,4]diazepin-6-one DCLK1 inhibitors, resulting in the identification of DCLK1-IN-1

    Application of photogrammetry to generate quantitative geobody data in ephemeral fluvial systems

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    Outcrop studies are often used as analogues to subsurface sedimentary reservoirs, with photogrammetry representing a useful technique to obtain quantitative geometrical data of sedimentary architectures. Digital photogrammetry techniques were used to study fluvial sediments of the Lower Jurassic Kayenta Formation of the western USA, and model-extracted statistics for channel and sheetflood elements, relevant to reservoir modelling, were compared to 1D and 2D datasets from the same outcrops. Results suggest that the 1D/2D data significantly underestimated element dimensions and ranges in ephemeral-fluvial systems. Consequently, this study demonstrates the value of photogrammetric techniques for obtaining statistically relevant and more accurate reservoir modelling input data from outcrop

    Discovery of a Selective Inhibitor of Doublecortin Like Kinase 1

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    Doublecortin like kinase 1 (DCLK1) is an understudied kinase that is upregulated in a wide range of cancers, including pancreatic ductal adenocarcinoma (PDAC). However, little is known about its potential as a therapeutic target. We used chemoproteomic profiling and structure-based design to develop a selective, in vivo-compatible chemical probe of the DCLK1 kinase domain, DCLK1-IN-1. We demonstrate activity of DCLK1-IN-1 against clinically relevant patient-derived PDAC organoid models and use a combination of RNA-sequencing, proteomics and phosphoproteomics analysis to reveal that DCLK1 inhibition modulates proteins and pathways associated with cell motility in this context. DCLK1-IN-1 will serve as a versatile tool to investigate DCLK1 biology and establish its role in cancer

    Functional Diffusion Tensor Imaging: Measuring Task-Related Fractional Anisotropy Changes in the Human Brain along White Matter Tracts

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    Functional neural networks in the human brain can be studied from correlations between activated gray matter regions measured with fMRI. However, while providing important information on gray matter activation, no information is gathered on the co-activity along white matter tracts in neural networks.We report on a functional diffusion tensor imaging (fDTI) method that measures task-related changes in fractional anisotropy (FA) along white matter tracts. We hypothesize that these fractional anisotropy changes relate to morphological changes of glial cells induced by axonal activity although the exact physiological underpinnings of the measured FA changes remain to be elucidated. As expected, these changes are very small as compared to the physiological noise and a reliable detection of the signal change would require a large number of measurements. However, a substantial increase in signal-to-noise ratio was achieved by pooling the signal over the complete fiber tract. Adopting such a tract-based statistics enabled us to measure the signal within a practically feasible time period. Activation in the sensory thalamocortical tract and optic radiation in eight healthy human subjects was found during tactile and visual stimulation, respectively.The results of our experiments indicate that these FA changes may serve as a functional contrast mechanism for white matter. This noninvasive fDTI method may provide a new approach to study functional neural networks in the human brain

    Argyrin B a non-competitive inhibitor of the human immunoproteasome exhibiting preference for β1i

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    Inhibitors of the proteasome have found broad therapeutic applications however, they show severe toxicity due to the abundance of proteasomes in healthy cells. In contrast, inhibitors of the immunoproteasome, which is upregulated during disease states, are less toxic and have increased therapeutic potential including against autoimmune disorders. In this project, we report argyrin B, a natural product cyclic peptide to be a reversible, non-competitive inhibitor of the immunoproteasome. Argyrin B showed selective inhibition of the β5i and β1i sites of the immunoproteasome over the β5c and β1c sites of the constitutive proteasome with nearly 20-fold selective inhibition of β1i over the homologous β1c. Molecular modelling attributes the β1i over β1c selectivity to the small hydrophobic S1 pocket of β1i and β5i over β5c to site-specific amino acid variations that enable additional bonding interactions and stabilization of the binding conformation. These findings facilitate the design of immunoproteasome selective and reversible inhibitors that may have a greater therapeutic potential and lower toxicity

    Transcribed enhancers lead waves of coordinated transcription in transitioning mammalian cells

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    Although it is generally accepted that cellular differentiation requires changes to transcriptional networks, dynamic regulation of promoters and enhancers at specific sets of genes has not been previously studied en masse. Exploiting the fact that active promoters and enhancers are transcribed, we simultaneously measured their activity in 19 human and 14 mouse time courses covering a wide range of cell types and biological stimuli. Enhancer RNAs, then messenger RNAs encoding transcription factors, dominated the earliest responses. Binding sites for key lineage transcription factors were simultaneously overrepresented in enhancers and promoters active in each cellular system. Our data support a highly generalizable model in which enhancer transcription is the earliest event in successive waves of transcriptional change during cellular differentiation or activation

    Interventions for families affected by HIV

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    Family-based interventions are efficacious for human immunodeficiency virus (HIV) detection, prevention, and care, but they are not broadly diffused. Understanding intervention adaptation and translation processes can support evidence-based intervention (EBI) diffusion processes. This paper provides a narrative review of a series of EBI for families affected by HIV (FAH) that were adapted across five randomized controlled trials in the US, Thailand, and South Africa over 15 years. The FAH interventions targeted parents living with HIV and their children or caregiver supports. Parents with HIV were primarily mothers infected through sexual transmission. The EBIs for FAH are reviewed with attention to commonalities and variations in risk environments and intervention features. Frameworks for common and robust intervention functions, principles, practice elements, and delivery processes are utilized to highlight commonalities and adaptations for each location, time period, and intervention delivery settings. Health care, housing, food, and financial security vary dramatically in each risk environment. Yet, all FAH face common health, mental health, transmission, and relationship challenges. The EBIs efficaciously addressed these common challenges and were adapted across contexts with fidelity to robust intervention principles, processes, factors, and practices. Intervention adaptation teams have a series of structural decision points: mainstreaming HIV with other local health priorities or not; selecting an optimal delivery site (clinics, homes, community centers); and how to translate intervention protocols to local contexts and cultures. Replication of interventions with fidelity must occur at the level of standardized functions and robust principles, processes, and practices, not manualized protocols. Adopting a continuous quality improvement paradigm will enhance rapid and global diffusion of EBI for FAH
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