Medical Clinic and Polyclinic I
  1. Homepage LMU Hospital
  2. Medical Clinic and Polyclinic I
  3. Research and teaching
  4. Basic research
  5. AG Ishikawa-Ankerhold

AG Ishikawa-Ankerhold

Mechanisms of platelet biogenesis and their impact on immune thrombosis using intravital microscopy

Intravital microscopy(IVM) is the method of choice for the direct observation of dynamic cellular processes in living organisms. The primary goal is to study the interactions between cells in tissues and organs in their natural environment, both under normal physiological conditions and in disease models. This approach provides unique insights that cannot be obtained with any other method at comparable spatial and temporal resolution.

The high-resolution observation of cellular microenvironments in living organisms poses several 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 live drift correction software(VivoFollow software 7,12) to correct or minimize motion artifacts caused by respiration and cardiac activity.

In addition to developing the necessary technological and methodological framework, we have also established a number 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 in the Collaborative Research Center (SFB) 914, which focused on immune cell migration in inflammation, development and disease. There, we provided a core competence platform for 4D multiphoton intravital microscopy of immune cell transport in mouse models. In CRC 1321, which deals with the modeling and control of pancreatic cancer, our work focuses on the investigation of mechanisms that promote coagulation and thrombosis during metastasis. In addition, we participate in numerous collaborative projects, including the SFB 1123, which focuses on atherosclerosis and new therapeutic targets.

An important focus of our research group is the study of immune thrombosis, in particular the mechanisms regulating platelet biogenesis in the bone marrow and their impact on thromboinflammatory diseases. In this context, we have recently discovered an important regulatory mechanism of megakaryopoiesis in which plasmacytoid dendritic cells release interferon-alpha and thus influence platelet production. This groundbreaking discovery, published in Nature 5 (2024), was made possible by the use of IVM and highlights the power of this technology in revealing cell interactions in vivo. Understanding this mechanism provides new insights into the role of immune regulation in platelet formation and its potential contribution to immune thrombotic events.

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

A major advantage of our work is its close connection to clinical applications. Located at the interface between basic research and clinical medicine, our studies aim to bridge the gap between scientific discovery and medical innovation.

Methods

The expertise of AG Ishikawa-Ankerhold includes a wide range of translational mouse models for diseases covering various tissues and organs, including skin, liver, stomach, kidney, spleen, pancreas, placenta, yolk sac, brain, adipose tissue, bone and bone marrow, intestine and muscle tissue(Figure 1).

LMU Klinikum





Figure 1. multiphoton intravital imaging of mouse tissues. Representative intravital multiphoton microscopy (IVM) images of various mouse organs, including brain, bone marrow, liver, stomach, pancreas and yolk sac. The images show immune cells, tumor cells and blood vessels visualized using fluorescent markers. This technique enables real-time tracking of cell dynamics and facilitates the observation of therapeutic interventions in vivo. Different colors represent different structures or cell types and help to investigate tissue-specific interactions and disease progression.

To study these models with high spatial and temporal resolution, we use state-of-the-art intravital imaging techniques, with a focus on 4D multiphoton microscopy and confocal laser scanning microscopy. These technologies allow us to capture dynamic cellular processes in vivo with unprecedented precision.

In addition to advanced imaging, our methodological spectrum includes

  • Advanced intravital imaging techniques using 4D confocal laser scanning and multiphoton microscopy (link to IVM website)

  • 3D printing technologies for customization of sample holders to ensure optimal positioning and stability during imaging
  • Image analysis (Imaris, ZEN and Fiji software), multidimensional image processing and image reconstruction to enable a deeper understanding of complex biological structures and interactions
  • Immunohistochemical/immunofluorescence characterization of tissues and cell types and use of live cell stains to visualize specific biological processes
  • Flow cytometric characterization and separation of different cell populations, enabling targeted analyses and functional studies
  • Cell migration and chemotaxis assays using flow chambers, allowing us to study the directional movement of cells in response to different stimuli

By integrating these advanced methods, we aim to refine disease models, improve imaging accuracy and contribute to a deeper understanding of cell behavior in both healthy and diseased individuals.


Imaging core facility
Originally translated with DeepL