Medizinische Klinik und Poliklinik I
  1. Startseite LMU Klinikum
  2. Medizinische Klinik und Poliklinik I
  3. Forschung und Lehre
  4. Grundlagenforschung
  5. AG Ishikawa-Ankerhold

AG Ishikawa-Ankerhold

  • Mechanisms of Platelet Biogenesis and Their Implications in Immunothrombosis Using Intravital Microscopy

    Intravital microscopy (IVM) is the method of choice for directly observing dynamic cellular processes within living organisms. The primary objective is to study cell-to-cell interactions within tissues and organs in their most native environment, both under normal physiological conditions and in disease models. This approach provides unique insights that are unattainable with any other method at comparable spatial and temporal resolution.

    The high-resolution observation of cellular microenvironments in living organisms presents various technological, preparative, and methodological challenges. To address these, we employ state-of-the-art 4D in vivo imaging techniques, including confocal laser scanning and multiphoton microscopy, combined with advanced software for live drift correction (VivoFollow software 7,12) to correct or minimize motion artifacts caused by respiration and cardiac activity.

    Beyond developing the necessary technological and methodological frameworks, we have also established a range of mouse models that, due to their genetic similarity to humans, facilitate the study of human disease patterns and the development of appropriate therapeutic approaches.

    Our research played a central role within Collaborative Research Center (CRC) 914, focusing on immune cell migration in inflammation, development, and disease, where we provide a core competence platform for 4D multiphoton intravital microscopy of immune cell trafficking in mouse models. In CRC 1321, dedicated to modeling and targeting pancreatic cancer, our work is centered on investigating mechanisms that promote coagulation and thrombosis during metastasis. Additionally, we contribute to numerous collaborative projects, including CRC 1123, which explores atherosclerosis and novel therapeutic targets.

    A significant focus of our research group is the study of immunothrombosis, particularly the mechanisms regulating platelet biogenesis in the bone marrow and their implications in thrombo-inflammatory diseases. In this context, we recently discovered a key regulatory mechanism of megakaryopoiesis, where plasmacytoid dendritic cells release interferon-alpha, influencing platelet production. This groundbreaking discovery, published in Nature 5 (2024), was made possible using IVM, highlighting the power of this technology in uncovering cellular interactions in vivo. Understanding this mechanism provides new insights into the role of immune regulation in platelet formation and its potential contributions to immunothrombotic events.

    Our research group is dedicated to both the advancement and standardization of intravital microscopy techniques and the development of highly informative mouse models (link to the IVM webpage). Our scientific focus encompasses cardiovascular research, immunothrombosis processes, as well as the cellular dynamics and interactions of immune cells with pathogens, cancer cells, and within embryonic development.

    A key advantage of our work is its close connection to clinical applications. Positioned at the intersection of fundamental research and clinical medicine, our studies aim to bridge the gap between scientific discovery and medical innovation.

    Methods

    AG Ishikawa-Ankerhold expertise encompasses a broad range of murine translational disease models, covering various tissues and organs, including the skin, liver, stomach, kidney, spleen, pancreas, placenta, yolk sac, brain, adipose tissue, bone and bone marrow, intestine, and muscle tissue, among others (Figure 1).

    LMU Klinikum





    Figure 1. Multiphoton Intravital Imaging of Murine Tissues. Representative intravital multiphoton microscopy (IVM) images of various murine organs, including the brain, bone marrow, liver, stomach, pancreas, and yolk sac. The images depict immune cells, tumor cells, and blood vessels, visualized using fluorescent markers. This technique enables real-time tracking of cellular dynamics and facilitates the observation of therapeutic interventions in vivo. Different colors represent distinct structures or cell types, aiding in the study of tissue-specific interactions and disease progression.

    To investigate these models with high spatial and temporal resolution, we employ cutting-edge intravital imaging techniques, with a strong emphasis on 4D multiphoton microscopy and confocal laser-scanning microscopy. These technologies allow us to capture dynamic cellular processes in vivo with unparalleled precision.

    In addition to advanced imaging, our methodological spectrum includes:

    • Advanced intravital imaging techniques, utilizing 4D confocal laser scanning and multiphoton microscopy (link to the IVM webpage)
    • 3D printing technologies for the customization of sample holders, ensuring optimal positioning and stability during imaging
    • Image analysis (Imaris, ZEN, Fiji softwares), multi-dimensional image processing, and image reconstruction, enabling a deeper understanding of complex biological structures and interactions
    • Immunohistochemical/Immunofluorescence characterization of tissues and cell types, as well as the use of live-cell dyes to visualize specific biological processes
    • Flow cytometry characterization and separation of diverse cell populations, facilitating targeted analysis and functional studies
    • Cell migration and chemotaxis assays using flow chambers, which allow us to study the directed movement of cells in response to various stimuli

    Through the integration of these advanced methodologies, we aim to refine disease models, enhance imaging accuracy, and contribute to a deeper understanding of cellular behavior in both health and disease.