Renal cells respond differently on various substrates in response to hydrostatic pressure

Several kidney pathologies result in elevated pressures within the renal interstitial fluid, thereby affecting cell function. Traditionally, these and related studies have been performed on rigid substrates. The objective of the current study was, therefore, to better simulate in vivo conditions by performing cell studies on a variety of substrates including fibronectin, gelatin, tissue culture plasticware, glass, and PLGA. In vitro studies on these substrates were performed with tubular and medullary renal cells. Specifically, changes in cell number and microfilament arrangement were examined following exposure to pathological (180 and 300 cmH₂O) pressures for 24 hours. Cell number studies provided evidence that exposure to pressures of 180 and 300 cmH₂O resulted in increased tubular renal cell numbers. In contrast, pressure-exposed medullary cell numbers were decreased in response to 180 and 300 cmH₂O. In both cell lines this response was more drastic in response to 300 cmH₂O pressure. In addition, substrate-dependent changes in microfilament structures took place in pressure-exposed renal cells. In combination, these results prove that the function of renal cells was affected by both substrate and pressure exposure. Hopefully, elucidating such renal cell responses to pressure will aid in the design of novel, targeted drug therapies for treating kidney pathologies.