?Secretory diarrhea is a leading cause of death worldwide among children under the age of five. Its pathology involves cystic fibrosis transmembrane conductance regulator CFTR, which provides a primary pathway for Cl- secretion. Targeting CFTR to prevent/reduce losses of electrolytes and water is a therapeutic strategy. Lysophosphatidic acid (LPA), a naturally occurring phospholipid mediator acts through G-protein-coupled receptors (GPCRs). Our research group has demonstrated that the LPA2 GPCR inhibits CFTR-dependent Cl- transport in intestinal epithelial cells. We have synthesized Rx100, a potent and metabolically stabilized agonist for the LPA2 GPCR. We have demonstrated that Rx100 significantly inhibited cholera toxin (CTX)-induced CFTR-mediated secretory diarrhea in mice. We propose to develop Rx100 into a highly effective anti-diarrheal agent. Aim #1. Optimize the efficacy of Rx100 in inhibiting (CTX)-induced diarrhea 1.1. Determine the oral bioavailability of Rx100 in mice. 1.2. Determine and optimize the anti-diarrheal effect of Rx100 by oral delivery. 1.3. Determine and optimize the anti-diarrheal effect of Rx100 by parenteral delivery Aim #2. Confirm the efficacy of Rx100 in inhibiting CTX-induced diarrhea Aim #3. Evaluate the anti-diarrheal effect of Rx100 in inhibiting Escherichia coli toxin and Citrobacter rodentium infection-induced diarrhea in mice. Methods: (1) Oral Rx100 bioavailability under 1.1 will be determined using tandem mass spectrometry detection (LC/MS/MS). (2) For Rx100's efficacy studies under 1.2 & 1.3, we will use an open-loop mouse model of CTX-induced diarrhea. (3) We will confirm Rx100's efficacy under aim #2 using a closed-loop mouse model of CTX-induced diarrhea. (4) We will also test Rx100's efficacy in a closed-loop model of Escherichia coli heat-stable toxin-induced intestinal fluid secretion under aim #3. We will also test Rx100's efficacy using a mouse model of C. rodentium infection under aim #3. Relevance to Public Health: Rx100 can be developed into a highly effective anti-diarrheal drug for the benefit of human beings.
Public Health Relevance Statement: Public Health Relevance: Secretory diarrhea is a leading cause of death worldwide among children under the age of five. No truly satisfactory therapeutic agents are available yet and oral rehydration remains the primary approach in managing secretory diarrhea. We propose to develop Rx100 into a highly effective anti- diarrheal agent.
NIH Spending Category: Digestive Diseases; Foodborne Illness
Project Terms: Age; Agonist; analog; Apical; Bacteria; base; Biological; Biological Availability; Cause of Death; Chemical Structure; Child; Chloride Channels; Cholera Toxin; Citrobacter rodentium; Clinical; clinically relevant; Computer Simulation; Cyclic AMP; Cyclic GMP; Cystic Fibrosis Transmembrane Conductance Regulator; Data; Dehydration; Detection; Development; Diarrhea; Dose; Drug Delivery Systems; Electrolytes; enteric pathogen; Epithelial Cells; Escherichia coli; Escherichia coli Infections; Fluids and Secretions; Food; Foundations; G-Protein-Coupled Receptors; heat stable toxin (E coli); Human; Hyperactive behavior; Infection; inhibitor/antagonist; Injection of therapeutic agent; Intervention; Intestines; liquid chromatography mass spectrometry; Liquid substance; lysophosphatidic acid; Lysophospholipids; Mediating; Mediator of activation protein; Methods; Modeling; mouse model; Mus; Oral; Oral Administration; Pathogenesis; Pathology; Pathway interactions; Pharmaceutical Preparations; Phospholipids; prevent; public health medicine (field); public health relevance; Regimen; Rehydrations; Research; response; Route; Subcutaneous Injections; success; Surface; tandem mass spectrometry; Testing; Therapeutic; Therapeutic Agents; Time; Toxin; Water
