Publications

@article{pike_high-throughput_2025,

title = {High-throughput assay for predicting diarrhea risk using a 2D human intestinal stem cell-derived model},

author = {Colleen M. Pike and James A. Levi and Lauren A. Boone and Swetha Peddibhotla and Jacob Johnson and Bailey Zwarycz and Maureen K. Bunger and William Thelin and Elizabeth M. Boazak},

url = {https://www.sciencedirect.com/science/article/pii/S0887233325000347},

doi = {10.1016/j.tiv.2025.106040},

issn = {0887-2333},

year  = {2025},

date = {2025-06-01},

urldate = {2025-06-01},

journal = {Toxicology In Vitro},

volume = {106},

pages = {106040},

abstract = {Gastrointestinal toxicities (GITs) in clinical trials often lead to dose-limitations that reduce drug efficacy and delay treatment optimization. Preclinical animal models do not accurately replicate human physiology, leaving few options for early detection of GITs, such as diarrhea, before human studies. Chemotherapeutic agents, known to cause clinical diarrhea, frequently target mitotic cells. Therefore, we hypothesized a model utilizing proliferative cell populations derived from human intestinal crypts would predict clinical diarrhea occurrence with high accuracy. Here, we describe the development of a diarrhea prediction assay utilizing RepliGut® Planar, a primary intestinal stem cell-derived platform. To evaluate the ability of this model to predict clinical diarrhea risk, we assessed toxicity of 30 marketed drugs by measuring cell proliferation (EdU incorporation), cell abundance (nuclei quantification), and barrier formation (TEER) in cells derived from three human donors. Dose response curves were generated for each drug, and the IC15 to Cmax ratio was used to identify a threshold for assay positivity. This model accurately predicted diarrhea potential, achieving an accuracy of 91 % for proliferation, 90 % for abundance, and 88 % for barrier formation. In vitro toxicity screening using primary proliferative cells may reduce clinical diarrhea and ultimately lead to safer and more effective treatments for patients.},

keywords = {Adverse events, Diarrhea, Epithelium, High throughput, In vitro model, Intestine},

pubstate = {published},

tppubtype = {article}

}

@article{debad_trust_2024,

title = {Trust your gut: Establishing confidence in gastrointestinal models – An overview of the state of the science and contexts of use},

author = {Susan Debad and David Allen and Omari Bandele and Colin Bishop and Michaela Blaylock and Paul Brown and Maureen K. Bunger and Julia Y. Co and Lynn Crosby and Amber B. Daniel and Steve S. Ferguson and Kevin Ford and Gonçalo Gamboa da Costa and Kristin H. Gilchrist and Matthew W. Grogg and Maureen Gwinn and Thomas Hartung and Simon P. Hogan and Ye Eun Jeong and George E. N. Kass and Elaina Kenyon and Nicole C. Kleinstreuer and Ville Kujala and Patrik Lundquist and Joanna Matheson and Shaun D. McCullough and Angela Melton-Celsa and Steven Musser and Ilung Oh and Oluwakemi B. Oyetade and Sarita U. Patil and Elijah J. Petersen and Nakissa Sadrieh and Christie M. Sayes and Benjamin S. Scruggs and Yu-Mei Tan and Bill Thelin and M. Tyler Nelson and José V. Tarazona and John F. Wambaugh and Jun-Young Yang and Changwoo Yu and Suzanne Fitzpatrick},

url = {https://altex.org/index.php/altex/article/view/2787},

doi = {10.14573/altex.2403261},

issn = {1868-8551},

year  = {2024},

date = {2024-07-16},

urldate = {2024-07-16},

journal = {ALTEX},

volume = {41},

number = {3},

pages = {402–424},

abstract = {The webinar series and workshop titled “Trust Your Gut: Establishing Confidence in Gastrointestinal Models – An Overview of the State of the Science and Contexts of Use” was co-organized by NICEATM, NIEHS, FDA, EPA, CPSC, DoD, and the Johns Hopkins Center for Alternatives to Animal Testing (CAAT) and hosted at the National Institutes of Health in Bethesda, MD, USA on October 11-12, 2023. New approach methods (NAMs) for assessing issues of gastrointestinal tract (GIT)- related toxicity offer promise in addressing some of the limitations associated with animal-based assessments. GIT NAMs vary in complexity, from two-dimensional monolayer cell line-based systems to sophisticated 3-dimensional organoid systems derived from human primary cells. Despite advances in GIT NAMs, challenges remain in fully replicating the complex interactions and pro­cesses occurring within the human GIT. Presentations and discussions addressed regulatory needs, challenges, and innovations in incorporating NAMs into risk assessment frameworks; explored the state of the science in using NAMs for evaluating systemic toxicity, understanding absorption and pharmacokinetics, evaluating GIT toxicity, and assessing potential allergenicity; and discussed strengths, limitations, and data gaps of GIT NAMs as well as steps needed to establish confidence in these models for use in the regulatory setting. 

Plain language summaryNon-animal methods to assess whether chemicals may be toxic to the human digestive tract promise to complement or improve on animal-based methods. These approaches, which are based on human or animal cells and/or computer models, are faced with their own technical challenges and need to be shown to predict adverse effects in humans. Regulators are tasked with evaluating submitted data to best protect human health and the environment. A webinar series and workshop brought together scientists from academia, industry, military, and regulatory authorities from dif­ferent countries to discuss how non-animal methods can be integrated into the risk assessment of drugs, food additives, dietary supplements, pesticides, and industrial chemicals for gastrointestinal toxicity.},

keywords = {Adverse events, Co-culture model, Enteroendocrine Cells, epithelial barrier, Gut barrier function, Gut liver microphysiological system, in vitro models, intestinal barrier, microphysiological system, microphysiological systems, organ-on-chips},

pubstate = {published},

tppubtype = {article}

}

@article{sarma_design_2023,

title = {Design of 8-mer Peptides that Block Clostridioides difficile Toxin A in Intestinal Cells},

author = {Sudeep Sarma and Carly M. Catella and Ellyce T. San Pedro and Xingqing Xiao and Deniz Durmusoglu and Stefano Menegatti and Nathan Crook and Scott T. Magness and Carol K. Hall},

doi = {10.1101/2023.01.10.523493},

year  = {2023},

date = {2023-01-12},

urldate = {2023-01-12},

pages = {2023.01.10.523493},

abstract = {Clostridioides difficile ( C. diff .) is a bacterium that causes severe diarrhea and inflammation of the colon. The pathogenicity of C. diff . infection is derived from two major toxins, toxins A (TcdA) and B (TcdB). Peptide inhibitors that can be delivered to the gut to inactivate these toxins are an attractive therapeutic strategy. In this work, we present a new approach that combines a pep tide b inding d esign algorithm (PepBD), molecular-level simulations, rapid screening of candidate peptides for toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block the glucosyltransferase activity of TcdA by targeting its glucosyltransferase domain (GTD). Using PepBD and explicit-solvent molecular dynamics simulations, we identified seven candidate peptides, SA1-SA7. These peptides were selected for specific TcdA GTD binding through a custom solid-phase peptide screening system, which eliminated the weaker inhibitors SA5-SA7. The efficacies of SA1-SA4 were then tested using a trans-epithelial electrical resistance (TEER) assay on monolayers of the human gut epithelial culture model. One peptide, SA1, was found to block TcdA toxicity in primary-derived human jejunum (small intestinal) and colon (large intestinal) epithelial cells. SA1 bound TcdA with a K D of 56.1 ± 29.8 nM as measured by surface plasmon resonance (SPR). 

SIGNIFICANCE STATEMENT: Infections by Clostridioides difficile , a bacterium that targets the large intestine (colon), impact a significant number of people worldwide. Bacterial colonization is mediated by two exotoxins: toxins A and B. Short peptides that can inhibit the biocatalytic activity of these toxins represent a promising strategy to prevent and treat C. diff . infection. We describe an approach that combines a Peptide B inding D esign (PepBD) algorithm, molecular-level simulations, a rapid screening assay to evaluate peptide:toxin binding, a primary human cell-based assay, and surface plasmon resonance (SPR) measurements to develop peptide inhibitors that block Toxin A in small intestinal and colon epithelial cells. Importantly, our designed peptide, SA1, bound toxin A with nanomolar affinity and blocked toxicity in colon cells.},

keywords = {Adverse events, epithelial barrier, In vitro model, inflammatory bowel disease, intestinal organoids, intestinal stem cells, microbiome},

pubstate = {published},

tppubtype = {article}

}