Nephrotoxicity and Kidney Transport Assessment on 3D Perfused Proximal Tubules

Abstract

Proximal tubules in the kidney play a crucial role in reabsorbing and eliminating substrates from the body into the urine, leading to high local concentrations of xenobiotics. This makes the proximal tubule a major target for drug toxicity that needs to be evaluated during the drug development process. Here, we describe an advanced in vitro model consisting of fully polarized renal proximal tubular epithelial cells cultured in a microfluidic system. Up to 40 leak-tight tubules were cultured on this platform that provides access to the basolateral as well as the apical side of the epithelial cells. Exposure to the nephrotoxicant cisplatin caused a dose-dependent disruption of the epithelial barrier, a decrease in viability, an increase in effluent LDH activity, and changes in expression of tight-junction marker zona-occludence 1, actin, and DNA-damage marker H2A.X, as detected by immunostaining. Activity and inhibition of the efflux pumps P-glycoprotein (P-gp) and multidrug resistance protein (MRP) were demonstrated using fluorescence-based transporter assays. In addition, the transepithelial transport function from the basolateral to the apical side of the proximal tubule was studied. The apparent permeability of the fluorescent P-gp substrate rhodamine 123 was decreased by 35% by co-incubation with cyclosporin A. Furthermore, the activity of the glucose transporter SGLT2 was demonstrated using the fluorescent glucose analog 6-NBDG which was sensitive to inhibition by phlorizin. Our results demonstrate that we developed a functional 3D perfused proximal tubule model with advanced renal epithelial characteristics that can be used for drug screening studies.

Recapitulation of Particulate matter Effected Human Alveolus on Chip Inflammatory Responses

“…IL-13 directly affect human airway epithelium and involved in inflammation of respiratory tract, respiratory tract hyperresponsiveness, goblet cell hyperplasia and mucus hypersecretion eventually subepithelial fibrosis occurs as a consequence of airway inflammation similar to that observed in airway mucosa of the individuals with asthma (43,44). In our experiment concentration of IL-13 found highest in media samples at 24 IL-6 is a cytokine has been considered as biomarker of inflammation rather than a regulatory cytokine with ability to modulate immune responses (45). In response to allergen stimulation to lung airway, IL- In order to achieve this goal, we select three levels of PM provided by daily climate control conditions of the country, Good, bad and worst and followed the exposure scheme that one individual can incidence of many diseases in our automated and sophisticated organ on chip platform.…”

Pharmacokinetics and Toxicokinetics Roles of Membrane Transporters at Kidney Level

“…OAT1, expressed by the SLC22A6 gene, is one of the most expressed transmembrane proteins in the adult kidney, located in the basolateral membrane of the cells of the proximal tubule (23), playing an important role in the clearance of a wide variety of xenobiotics (24). The expression of this transporter in the kidney increases during gestation and after birth (23).…”

“…On the other hand, besides being found in greater quantities, it is also present in other places like the choroid plexus, the brain capillary endothelium, and the retina (23). OAT1 and OAT3 have some common substances as substrates (3,23,24); however, these have higher affinity for one transporter or the other. Another difference between OAT1 and OAT3 is that OAT3 has higher affinity for carrying cations than OAT1 (23), whereas OAT1 shows higher affinity for carrying PAH (3,21).…”

“…In the kidney, the influx of cisplatin is performed by OCT2 and copper transporter 1 (SLC31A1) and basolateral transporters of proximal tubular cells, whereas efflux is performed by MATE1, MRP2 and P-gp, apical transporters (9,12). The combined activity of these transporters determines the inexistence of cisplatin accumulation, which will correlate with nephrotoxicity (24).…”

A Perfused Microfluidic System to Study the Differentiation of Neural Stem Cells in vitro

“…A perfused culture can constantly provide continuous nutrient supply as well as removing the waste, thus maintaining a fresh and stable local microenvironment. Some perfused culture systems have been developed for use for either cell expansion [Okamoto et al, 2013;Chapman, 2014] or three-dimensional cell culture [Parrish et al, 2018;Vormann et al, 2018].…”