MICROFILAMENTS ARE INVOLVED IN RENAL CELL RESPONSES TO SUSTAINED HYDROSTATIC PRESSURE

ABSTRACT Purpose: Increased pressures within renal interstitial fluid, as associated with a number of renal pathologies, could affect cell function and gene expression. The long-term objective of this research is to elucidate kidney cell responses to pathological hydrostatic pressures. Materials and Methods: In vitro studies were performed in 2 kidney cell lines (cortical tubular and medullary) to determine changes in cell numbers and cytoskeletal (specifically microfilament, microtubule and intermediate filament) arrangement following exposure to pathological (60 cm H 2 O) pressures. A novel pressure system was used to apply pressure to renal cells for up to 7 days. Cell counts and fluorescent staining were performed to determine alterations in response to pressure. Results: Exposure to pressures of 60 cm H 2 O resulted in increased renal cell numbers and rearrangement in individual microfilament structures after 7 days. Conclusions: These results prove that hydrostatic pressure alters the function of renal cells. In the future such knowledge of renal cell responses to pressure along with an understanding of the mechanisms involved will aid in the design of novel, targeted drug therapies for treating kidney pathologies.