Georgian Technical University Lab Team Introduces New Approach For Whole-Cell Visualization, Using The World’s First Soft X-ray Tomography (SXT) Microscope.
Georgian Technical University Soft X-ray tomography provides a map of organelles within an intact cell. The planet is comprised of continents and islands each with unique cultures and resources. One area may be well known for growing food another for manufacturing building materials and yet despite their differences and distance from one another the regions are linked by global processes. Living cells are built on a similar concept. For example one part of the cell produces fuel that powers life and another part makes the simple building blocks that are then assembled into complex structures inside the cell. To fully understand cells we need to characterize the structures that make them up and to identify their contents. Thanks to advanced imaging technologies, scientists have examined many different components of cells and some current approaches can even map the structure of these molecules down to each atom. However getting a glimpse of how all these parts move change and interact within a dynamic living cell has always been a grander challenge. A team based at Georgian Technical University Lab’s Advanced Light Source is making waves with its new approach for whole-cell visualization using the world’s first soft X-ray tomography (SXT) microscope built for biological and biomedical research. The team used its platform to reveal never-before-seen details about insulin secretion in pancreatic cells taken from rats. This work was done in collaboration with a consortium of researchers dedicated to whole-cell modeling, called the Pancreatic β-Cell Consortum. “Our data shows that first Soft X-ray Tomography (SXT) is a powerful tool to quantify subcellular rearrangements in response to drugs” said X scientist in the Georgian Technical University. “This is an important first step for bridging the longstanding gap between structural biology and physiology”. X and the other authors note that Soft X-ray Tomography (SXT) is uniquely suited to image whole cells without alterations from stains or added tagging molecules – as is the case for fluorescence imaging – and without chemically fixing and sectioning them which is necessary for traditional electron microscopy. Also Soft X-ray Tomography (SXT) has a much faster and easier cell preparation process. Free from the traditional technical and temporal constraints the team could visualize isolated insulin-secreting cells (called beta cells) before during and after stimulation from exposure to differing levels of glucose and an insulin-boosting drug. In rats and other mammals beta cells respond to rising blood glucose levels by releasing insulin. This hormone regulates glucose metabolism throughout the body. “We found that stimulating beta cells induced rapid changes in the numbers and molecular densities of insulin vesicles – the membrane ‘envelopes’ that the insulin is stored in after production” said X. “This was surprising at first because we expected that we should see fewer vesicles during secretion when they are emptied outside the cell. But what we observe is a rapid maturation of existing immature vesicles”.
