A Multitubular Kidney-on-Chip to Decipher Pathophysiological Mechanisms in Renal Cystic Diseases.

Bertrand Cinquin,Aude Battistella,Fanny Cayrac,Brice Lapin,Giacomo Gropplero,Sarah Myram,Sophie Demolombe,Charles Cavaniol,Isabelle Bonnet,Sylvie Coscoy,Stéphanie Descroix,Bastien Venzac

doi:10.3389/fbioe.2021.624553

Abstract

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a major renal pathology provoked by the deletion of PKD1 or PKD2 genes leading to local renal tubule dilation followed by the formation of numerous cysts, ending up with renal failure in adulthood. In vivo, renal tubules are tightly packed, so that dilating tubules and expanding cysts may have mechanical influence on adjacent tubules. To decipher the role of this coupling between adjacent tubules, we developed a kidney-on-chip reproducing parallel networks of tightly packed tubes. This original microdevice is composed of cylindrical hollow tubes of physiological dimensions, parallel and closely packed with 100–200 μm spacing, embedded in a collagen I matrix. These multitubular systems were properly colonized by different types of renal cells with long-term survival, up to 2 months. While no significant tube dilation over time was observed with Madin-Darby Canine Kidney (MDCK) cells, wild-type mouse proximal tubule (PCT) cells, or with PCT Pkd1+/- cells (with only one functional Pkd1 allele), we observed a typical 1.5-fold increase in tube diameter with isogenic PCT Pkd1-/- cells, an ADPKD cellular model. This tube dilation was associated with an increased cell proliferation, as well as a decrease in F-actin stress fibers density along the tube axis. With this kidney-on-chip model, we also observed that for larger tube spacing, PCT Pkd1-/- tube deformations were not spatially correlated with adjacent tubes whereas for shorter spacing, tube deformations were increased between adjacent tubes. Our device reveals the interplay between tightly packed renal tubes, constituting a pioneering tool well-adapted to further study kidney pathophysiology.

Highlights

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common genetic renal disease, and the fourth most common cause of end-stage renal failure worldwide, without curative therapies except dialysis or transplantation (Ghata and Cowley, 2017; Li, 2017)
We describe the development of a new generation of kidney-on-chip with parallel aligned circular tubes, of 80 μm diameter and 100 or 200 μm spacing, in a biocompatible and deformable collagen I
This chip was designed in order to reproduce geometrical, mechanical and biological characteristics of an array of renal proximal tubules with the aim to study physiopathological mechanisms of ADPKD

Summary

Introduction

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common genetic renal disease (incidence 1/1,000), and the fourth most common cause of end-stage renal failure worldwide, without curative therapies except dialysis or transplantation (Ghata and Cowley, 2017; Li, 2017). Fundamental mechanisms involved in cystogenesis are based on increased proliferation of epithelial tubular cells (Terzi et al, 1996; Yamaguchi et al, 2003; Cowley et al, 2006; Grimm et al, 2006; Lee, 2016) coupled with de-regulated apoptosis (Boca et al, 2006; Foy et al, 2012; Kurbegovic and Trudel, 2020), loss of planar polarity and misorientation during mitosis (Fischer et al, 2006; Castelli et al, 2013), and remodeling of extracellular matrix (ECM) (Wilson et al, 1992; Schafer et al, 1994; Ramasubbu et al, 1998; Joly et al, 2003; Subramanian et al, 2012) Relying on those mechanisms, human cysts reaching up to 3 mm in diameter detach from the parent tubule and migrate away while continuing expanding (Ghata and Cowley, 2017). Expanding cysts constrain the functional renal parenchyma, and participate to its progressive failure during ADPKD evolution

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