Successful Establishment of Equine Duodenal Organoids From Endoscopically-Guided Biopsies

Abstract: Background– Intestinal organoids are utilized for understanding epithelial biology, disease mechanisms, and drug metabolism in human medicine. They are increasingly important for personalized and precision medicine. To date, all published methods of producing equine intestinal organoids use tissue obtained post-mortem or via exploratory celiotomy, which limits the utility of this model.
Hypothesis– Duodenal organoids will be cultured from duodenal endoscopically-guided biopsies performed in standing sedating horses.
Animals– 5 healthy adult mares (age range: 12-21 years, 4 TB and 1 QH) from NC State Research herds.
Methods – After fasting, horses were sedated and gastroscopy was performed with a 3.25m endoscope. After passing into the proximal duodenum, 6-8 biopsies were obtained using 2.3mm serrated biopsy forceps (Figure 1A, B). Duodenal crypts were separated from the underlying lamina propria by mechanical and chemical dissociation (Figure 1D-F). Crypts were then filtered and plated in a 3D matrix (Matrigel). After polymerization, media was applied to the cultures and they were incubated at 37*C in 5% CO2. Organoid growth was monitored daily and media was changed as necessary. Media modifications with varying concentrations of R-spondin, a Wnt signaling molecule, were performed to test the requirements for organoid growth.
Results– Duodenal organoids were successfully cultured from endoscopically-guided biopsies from adult horses (Figure 1). Sufficient crypts for culture were obtained in 4/5 horses. R-spondin supplementation is required for duodenal organoid growth (Figure 2).
Conclusions and clinical importance– This study demonstrates duodenal organoid establishment from live adult horses, allowing for personalized medicine approaches based on organoid assays.