Effects of Shiga Toxin Type 2 on a Bioengineered Three-Dimensional Model of Human Renal Tissue

Abstract

dShiga toxins (Stx) are a family of cytotoxic proteins that can cause hemolytic-uremic syndrome (HUS), a thrombotic microangiopathy, following infections by Shiga toxin-producing Escherichia coli (STEC). Renal failure is a key feature of HUS and a major cause of childhood renal failure worldwide. There are currently no specific therapies for STEC-associated HUS, and the mechanism of Stx-induced renal injury is not well understood primarily due to a lack of fully representative animal models and an inability to monitor disease progression on a molecular or cellular level in humans at early stages. Three-dimensional (3D) tissue models have been shown to be more in vivo-like in their phenotype and physiology than 2D cultures for numerous disease models, including cancer and polycystic kidney disease. It is unknown whether exposure of a 3D renal tissue model to Stx will yield a more in vivo-like response than 2D cell culture. In this study, we characterized Stx2-mediated cytotoxicity in a bioengineered 3D human renal tissue model previously shown to be a predictor of drug-induced nephrotoxicity and compared its response to Stx2 exposure in 2D cell culture. Our results demonstrate that although many mechanistic aspects of cytotoxicity were similar between 3D and 2D, treatment of the 3D tissues with Stx resulted in an elevated secretion of the kidney injury marker 1 (Kim-1) and the cytokine interleukin-8 compared to the 2D cell cultures. This study represents the first application of 3D tissues for the study of Stx-mediated kidney injury.

Organoids as an in vitro model of human development and disease

“…Helicobacter pylori, a causal agent of gastritis and gastric cancer onset in humans, was recently found to efficiently colonize the luminal epithelia of human gastric organoids, resulting in major physiological changes, including an increase in proliferation due to oncogenic CagA and increased β-catenin signalling 23,24,69,70 . Additionally, some 3D tissue models have been applied to the study of microbial pathogenesis such as haemolytic uremic syndrome caused by Shiga-toxin-producing Escherichia coli 71 . Here, the renal organoids can provide a window to study the cells colonized by the bacterium and the subsequent manifestation in the tissue.…”

Shiga Toxins as Multi-Functional Proteins: Induction of Host Cellular Stress Responses, Role in Pathogenesis and Therapeutic Applications

“…In the mouse model of Stx-mediated renal damage, Stx2 targeted murine collecting duct epithelium with evidence of toxin-induced loss of function contributing to renal failure through the induction of apoptosis in Gb 3 + murine renal cortical and medullary tubular cells [ 124 ]. Recently, in order to monitor HUS disease progression utilizing a system more closely resembling the human kidney, DesRochers et al [ 125 ] investigated the effect of Stx2 on a bioengineered three-dimensional model of human renal tissue. They observed similar aspects of cytotoxicity following toxin exposure as had been described in two-dimensional cell culture [ 125 ].…”

“…Recently, in order to monitor HUS disease progression utilizing a system more closely resembling the human kidney, DesRochers et al [ 125 ] investigated the effect of Stx2 on a bioengineered three-dimensional model of human renal tissue. They observed similar aspects of cytotoxicity following toxin exposure as had been described in two-dimensional cell culture [ 125 ]. Numbers of apoptotic monocytes and neutrophils were significantly elevated in the circulation of HUS patients, and leukocyte cell death positively correlated with disease severity as monitored by admission to the intensive care unit [ 33 ].…”

Kidney-based in vitro models for drug-induced toxicity testing

“…To model kidney diseases, direct pathogen exposure and genome editing have been applied, depending on the cause of disease. Effects of Shiga toxin 2, a cytotoxic protein causing hemolytic-uremic syndrome (HUS), were studied in a 3D model of renal cortical epithelial cells (DesRochers et al 2015). And polycystic kidney disease was studied via CRISPR-Cas9 genome editing of PC-1 and -2 in iPSCderived kidney organoids (Czerniecki et al 2018;Freedman et al 2015).…”