Medizinische Universität Graz - Research portal
Selected Publication:
Karner, C.
Validation of a fluidic flow chamber with renal proximal tubule cells and investigation of ACKR4.
[ Diplomarbeit/Master Thesis (UNI) ] Universität Graz; 2025.
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- Authors Med Uni Graz:
- Advisor:
- Gauster Martin
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- Abstract:
- In the context of human health and wellbeing, effective communication between various processes is essential. Such processes include the oxygen concentration and the specific pH of organs. Fluid shear stress (FSS), generated by blood, plasma or urine flow in the body, is associated with these vital processes and directly affects cells in numerous organs. The resulting mechanical force impacts various aspects of cell function, including metabolism, morphology and endocrine activity. Furthermore, shear forces play a crucial role in the formation of microvilli, which serve to increase the surface area available for the uptake and exchange of substances. In order to analyse these changes, cells are subjected to flow chambers. While there are already some commercially available fluidic flow chambers that can be used to analyse the response of cells to FSS, these chambers are either too small for molecular analysis or cannot reach every organ-specific shear rate. Consequently, novel flow chambers were developed at Medical University of Graz (EP 22208565.6. PCT/EP2023/080546), which should be validated for a variety of research fields. In this master's thesis, the innovative fluidic flow chambers were validated for epithelial cells of the kidney, specifically for renal proximal tubule cells. The renal proximal tubule (PT) is exposed to a constant flow of unfiltered liquid. Consequently, these cells were selected for study. The physiological flow rate for renal PT cells is 1 dyne/cm². Human embryonal kidney cells (HEK293) were analysed on morphological and molecular level. Following the validation phase, a brief investigation was initiated into the subject area of the immune system, whereby atypical chemokine receptor 4 (ACKR4)-transfected HEK cells were used and examined using our flow system. These were provided by the nephrology department in Graz and were additionally subjected to a pathological flow rate of 2 dyne/cm². Following the completion of the flow experiments, the cells were harvested for subsequent downstream analysis. The experimental approach included cell culture with flow systems, immunohistochemistry, Western Blot, qPCR, proliferation and toxicity assays. The results showed slightly increased, non-significant cytotoxicity due to the shear rates. A trend also showed increased cell proliferation compared to the static controls. Gene analysis also revealed higher expression of several genes in many of the flow-treated samples. Staining showed the differences in membrane protein distribution between static and flow treatment. The findings of this study indicate the validation of the fluidic flow chamber has been successful for kidney's epithelial PT cells. Collaborations with the nephrology department in Graz will continue in order to further research the ACKR4 receptor. The results of the study highlight the importance of implementing different physiological conditions in the work with epithelial cells. Additional investigations of the flow chambers in other research areas have great potential for creating deeper insights in medical research.