A numerical analysis of the mechanosensory hypothesis of brush border microvilli

The flow rate in the proximal tubule of the kidney determines how quickly solutes are reabsorbed. Thus a sensitive system must be present to detect small changes in the flow rate. Recently, it was proposed that the brush border microvilli in the proximal tubule serve this function. To further investigate this hypothesis, we developed a finite element model of the microvillus cytoskeleton to analyze its deformation in the presence and absence of crosslinking proteins. Our model indicates that the stiffness of the crosslinkers could decrease the deflection of microvilli by up to two orders of magnitude as well as influence the deformed shape of the microvillus.