Environmental Toxin Screening Using Human-Derived 3D Bioengineered Liver and Cardiac Organoids.

Steven D Forsythe,Aleksander Skardal,Colin Bishop,Thomas Shupe,Anthony Atala,Mahesh Devarasetty,Shay Soker

doi:10.3389/fpubh.2018.00103

Abstract

Environmental toxins, such as lead and other heavy metals, pesticides, and other compounds, represent a significant health concern within the USA and around the world. Even in the twenty-first century, a plethora of cities and towns in the U.S. have suffered from exposures to lead in drinking water or other heavy metals in food or the earth, while there is a high possibility of further places to suffer such exposures in the near future. We employed bioengineered 3D human liver and cardiac organoids to screen a panel of environmental toxins (lead, mercury, thallium, and glyphosate), and charted the response of the organoids to these compounds. Liver and cardiac organoids were exposed to lead (10 µM-10 mM), mercury (200 nM-200 µM), thallium (10 nM-10 µM), or glyphosate (25 µM-25 mM) for a duration of 48 h. The impacts of toxin exposure were then assessed by LIVE/DEAD viability and cytotoxicity staining, measuring ATP activity and determining IC50 values, and determining changes in cardiac organoid beating activity. As expected, all of the toxins induced toxicity in the organoids. Both ATP and LIVE/DEAD assays showed toxicity in both liver and cardiac organoids. In particular, thallium was the most toxic, with IC50 values of 13.5 and 1.35 µM in liver and cardiac organoids, respectively. Conversely, glyphosate was the least toxic of the four compounds, with IC50 values of 10.53 and 10.85 mM in liver and cardiac organoids, respectively. Additionally, toxins had a negative influence on cardiac organoid beating activity as well. Thallium resulting in the most significant decreases in beating rate, followed by mercury, then glyphosate, and finally, lead. These results suggest that the 3D organoids have significant utility to be deployed in additional toxicity screening applications, and future development of treatments to mitigate exposures. 3D organoids have significant utility to be deployed in additional toxicity screening applications, such as future development of treatments to mitigate exposures, drug screening, and environmental toxin detection.

Highlights

Environmental toxins continue to represent a significant health concern within the United States and around the world
Liver organoids successfully formed at 4 days, with cardiac organoids taking 7 days to allow for self-propagating beating to occur
While countless environmental toxins exist, and there are many that are pertinent to human health, and many more that require study to understand their potential impacts on human health, we chose several traditional, well-studied toxins to challenge our organoid systems

Summary

Introduction

Environmental toxins continue to represent a significant health concern within the United States and around the world. Even in the twenty-first century, we continue to hear of cities and towns in the U.S have suffered from exposures to lead in drinking water and other heavy metals in food or the earth [1, 2]. Environmental heavy metals have long been known to cause cell and tissue damage, often leading to major health complications, especially in children [3]. Heavy metals are able to interact directly with nucleic acids and nuclear proteins resulting in DNA damage leading to altered cell function, cancer, and cell death [6, 7]. In addition to heavy metals, some compounds in pesticides have been determined to cause toxic effects in humans and wildlife, with many becoming banned due to these consequences, the most famous being DDT [8, 9]. In addition to cases of acute toxicity, possible negative chronic afflictions on exposed populations include cancers, diabetes, endocrine disruption, neurodegenerative diseases, and potential epigenetic changes [10,11,12,13,14,15]

Objectives

Methods

Results

Conclusion