Figure 9
From: Architecture-Guided Fluid Flow Directs Renal Biomineralization
Architecture-guided bioengineering model to explain interstitial renal biomineralization. Distal interstitial mineralization of the medullo-papillary complex (MPC). (A) MPC (no Randall’s plaque) with uriniferous tubules and vasa recta, along with velocity profiles (top) and transverse cross section with functional radius (Ro) are shown. The flow velocity profile within the uriniferous tubule with radius ‘ro’ (blue) and vasa recta (pink) is indicated by minimum velocity near the wall and maximum central flow velocity with minimal to no accumulation or tubular obstruction. The resulting shear stress in the tube with certain radius is a function of fluid viscosity “ν”, and a differential in velocity. The decrease in functional radius of the MPC due to occlusion of peripheral tubules (Fig. 8) results in subsequent local biomineralization events (B). The differential in circumferential strains resulting from progression of peritubular biomineralization within both uriniferous tubules and juxtaposed vasa recta trigger a mechano-biological switch. This switch initiates the progression of peritubular to interstitial biomineralization through expression of osteogenic markers by differentiating cells in these local environments. These events decrease tissue compliance that can further decrease the functional radius of the MPC.
