Episode 3: Insights of a Scientist, Nanomechanics in Living Cells
Episode 3: Insights of a Scientist, Nanomechanics in Living Cells
In this episode, Prof. Kristina Kusche-Vihrog, Director of the Lübeck Institute of Physiology, Germany, speaks about her fascinating work investigating the nanomechanical properties of cells, their role in physiological mechanisms and implications for medical conditions such as cardiovascular disease and hypertension.
She discusses the importance of endothelial cell stiffness in health, the role of the glycocalyx, and the impact of inflammatory processes on endothelial dysfunction. This episode explores bench-to-bedside AFM applications and potential future advancements in clinical diagnostics.
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How AFM is Transforming Cardiovascular Research
Atomic Force Microscopy (AFM) is an imaging technique widely used in industry, materials, and life sciences. AFM technology advances have made it a powerful technique to study living cells in (near-)physiological conditions, called BioAFM.
In episode 1 of our AFM podcast “Conversations on AFM”, we learned more about the origins and impact of AFM from Prof Dr Mervyn Miles. We then moved on to learn about “Applications of BioAFM in the Life Sciences” in the podcast episode 2 with Dr. Andre Körnig .
Here, we explore how AFM is transforming biomedical research. For this, we have interviewed Prof Kristina Kusche-Vihrog, the Director of the Lübeck Institute of Physiology. Her research focuses on the influence of inflammatory processes on endothelial dysfunction as a precursor to the development of cardiovascular diseases and hypertension.
Measuring Endothelial Cells with AFM
Endothelial Cells (ECs), which line our blood vessels, are central to maintaining blood flow and actively respond to physical and chemical changes. One key player in this is the actin cortex — a network of actin filaments just beneath the cell membrane — which plays a crucial role in determining cell stiffness. Another key feature of ECs is the glycocalyx, a thin mesh-like layer on the cell surface composed of sugars and proteins. The glycocalyx layer protects ECs from direct blood flow shear stress and plays a vital role in cell signalling, inflammation response, and vascular integrity. With the help of AFM, scientists can probe, measure and describe the glycocalyx and the underlying structures [1]
Dynamic morphological changes in living HUVEC cell, imaged at 37°C in full growth medium. Consecutive phase channel images show dynamic cellular events such as cytoskeleton reorganization (circle). Scan size: 7.17x7.17 µm. Sample courtesy of Prof. Dr. Stefan Zahler, LMU München, Germany.
Cellular Stiffness in Health and Disease
When thinking about cellular stiffness, we need to distinguish between physiology and pathophysiology. In a physiologically healthy state, ECs respond to and regulate blood pressure by releasing the vasodilator nitric oxide (NO). Using AFM and cellular stiffness measurements, it was found that softer ECs tend to release more NO. On the other hand, cells that are older or affected by certain diseases are stiffer and thus can no longer effectively release NO for blood pressure regulation [2]. Research suggests that this process of stiffening does not just happen in healthy ageing but is also found in autoimmune diseases and chronic inflammation, linking cardiovascular and immune system health [3].
Bench-to-Bedside AFM: From Patient Sera to Patient Stratification
Prof. Kusche-Vihrog shares that when studying chronic kidney disease, using Primary Human Umbilical Vein Endothelial Cells (HUVECs) and incubating them with patient sera, ECs were found to have a damaged glycocalyx and were stiffened [4]. The research group also found that EC stiffness, on the single-cell level, could be extrapolated to larger parts of the arterial system. Thus, their data suggest that cellular stiffness is a predictor of the systemic immune and vascular system status.
Ideally, these findings could be taken further using patient sera with conditions like hypertension or autoimmune diseases to stratify patients based on their unique cellular mechanics, potentially leading to more personalised treatments. Patient stratification in this way could provide a foundation for precision medicine, where treatments are tailored to the patient’s specific vascular profile and immune response.
Altogether, AFM could be used in predictive diagnostics, potentially identifying vascular health issues and inflammation risks.
Using AFM to Understand Immunity and Autoimmunity
Prof. Kusche-Vihrog shared with us that auto-antibody-mediated effects in a COVID-19 infection can lead to glycocalyx shedding and cell stiffening, effects which were correlated to levels of proinflammatory cytokines [5]. Together with collaborators, she is currently working to understand whether similar auto-antibody-mediated effects are observed in ECs for the autoimmune disease systemic sclerosis [6]. This adds to other AFM applications in systemic sclerosis, where it was found that fibroblasts are softer but with an unaltered surface topography in patients [7].
The Future of AFM in Biomedicine
Although AFM excels at reliably quantifying cell mechanics, Prof. Kusche-Vihrog says that a key challenge is the expertise needed to work with living cells while maintaining their optimal condition throughout experiments. She also hopes that AFM measurements will be standardised to a point where AFM can be used as a diagnostic tool in clinics.
You can also download our ressource collection to learn more about AFM technologies and their application.
References
- M. Giergiel, K. E. Malek-Zietek, J. Konior, and M. Targosz-Korecka, “Endothelial glycocalyx detection and characterization by means of atomic force spectroscopy: Comparison of various data analysis approaches,” Micron, vol. 151, p. 103153, Dec. 2021, doi: 10.1016/j.micron.2021.103153.
- A. Jannatbabaei, M. Tafazzoli-Shadpour, and E. Seyedjafari, “Effects of substrate mechanics on angiogenic capacity and nitric oxide release in human endothelial cells,” Annals of the New York Academy of Sciences, vol. 1470, no. 1, pp. 31–43, 2020, doi: 10.1111/nyas.14326.
- F. Porsch and C. J. Binder, “Autoimmune diseases and atherosclerotic cardiovascular disease,” Nat Rev Cardiol, vol. 21, no. 11, pp. 780–807, Nov. 2024, doi: 10.1038/s41569-024-01045-7.
- B. Fels et al., “Effects of Chronic Kidney Disease on Nanomechanics of the Endothelial Glycocalyx Are Mediated by the Mineralocorticoid Receptor,” International Journal of Molecular Sciences, vol. 23, no. 18, Art. no. 18, Jan. 2022, doi: 10.3390/ijms231810659.
- B. Fels et al., “Mineralocorticoid receptor-antagonism prevents COVID-19-dependent glycocalyx damage,” Pflugers Arch, vol. 474, no. 10, pp. 1069–1076, Oct. 2022, doi: 10.1007/s00424-022-02726-3.
- “MD A17 - Autoantibody-mediated effects on endothelial and immune cell signaling in systemic sclerosis: GRK2633 | Defining and Targeting Autoimmune Pre-Disease.” Accessed: Nov. 11, 2024. [Online]. Available: https://www.grk2633.uni-luebeck.de/projects/1st-generation/md-projects/md-a17-autoantibody-mediated-effects-on-endothelial-and-immune-cell-signaling-in-systemic-sclerosis
- A. Reich, M. Meurer, B. Eckes, J. Friedrichs, and D. J. Muller, “Surface morphology and mechanical properties of fibroblasts from scleroderma patients,” Journal of Cellular and Molecular Medicine, vol. 13, no. 8b, p. 1644, Jul. 2008, doi: 10.1111/j.1582-4934.2008.00401.x.
Interested in learning more about this topic?
You can find detailed applications and technical notes, expert-led webinars, and on-demand instrument and measurement demonstrations in our online resource library. Get instant, full-length access to all resources related to this podcast using the form below.
This resource collection includes:
- 1 full-length e-book
- 1 full-length application note
- 2 full length on-demand webinar recordings
- 2 real-time instrument demonstrations
FULL-LENGTH E-BOOK
Atomic Force Microscopy for Life Sciences
Learn about the life science research capabilities of atomic force microscopy, including working principles, mechanics, uses, and common challenges.
FULL-LENGTH APPLICATION NOTE
Investigation of Viruses Using Atomic Force Microscopy
Learn about AFM-based high-resolution topography imaging and advanced mechanical and electrical characterization of virus particles and their life cycle.
ON-DEMAND WEBINAR RECORDING
Probing Dynamic Mechanical Changes in Cells and Tissues by AFM
In this recording, guest speaker Dr. Guillaume Charras, University College London, UK, speaks about approaches for studying dynamic mechanical changes in cells and tissues and their role in morphogenesis.
REAL-TIME-DEMONSTRATION
Mechanics of Cells and Tissues
In this recording, Bruker applications experts demonstrate instrument setup, software configuration and calibration of Bruker's BioAFMs to acquire biomechanical data of cells and tissues.
ON-DEMAND WEBINAR RECORDING
AFM Mechanical Mapping of Large-Scale 3D Cellular Models
In this recording, Dr. Lydia Powell, Swansea University Medical School, UK, speaks about using 3D spheroid cellular models to study the mechanisms of drug resistance in ovarian cancer treatment, metastasis, and chronic wound biofilm-related infections, and how this research can be translated into the design and delivery of new therapies.
REAL-TIME DEMONSTRATION
Measurements over Large Sample Areas
In this recording, Bruker applications experts demonstrate the SmartMapping feature and how to set up experiments to perform measurements and microrheology over large sample areas with Bruker's BioAFMs.
