Purinergic Signaling Drives Multiple Aspects of Rotavirus Pathophysiology
Authors: Engevik Kristen , Gebert J. Thomas , Scribano Francesca , Hyser Joseph 
Published: May 2024

Background: Rotavirus causes life-threatening diarrhea in children, resulting in ~200,000 deaths each year. Rotavirus infects a limited number of cells at the tips of the villi in the small intestine; however, rotavirus is known to dysregulate cells distant from the site of infection through paracrine signaling. We recently identified that rotavirus infected cells release the purinergic signaling molecule ADP, which binds to the P2Y1 receptor on nearby uninfected cells; causing a signaling cascade that affects distant uninfected cells. In vitro P2Y1 was found to contribute to chloride and serotonin secretion; suggesting P2Y1 may activate pathways responsible for diarrhea. Hypothesis: We hypothesize that P2Y1 orchestrates cell-cell communication involved in diarrhea and infection severity. Methods: To elucidate the role of purinergic signaling via P2Y1 receptors during rotavirus infection, we used the mouse-like rotavirus (rD6/2) to investigate the effects of purinergic signaling in the context of homologous murine rotavirus infection in vivo. C57Black6 mouse pups were orally gavaged rD6/2 rotavirus at day 4-6 of age and assessed over the course of 5 days. Beginning at day 1 post infection, infected pups were treated daily by oral gavage with saline or 4mg/kg MRS2500, a P2Y1-selective, competitive antagonist. Stool was collected and scored for diarrhea daily prior to each treatment. Pups were euthanized and small intestine tissue was collected at 3- and 5-days post infection for immunostaining, qRT-PCR and luminal contents. Intestinal organoids derived from Balb/C pup jejunum were inoculated with rD6/2 rotavirus, followed by supplementation with vehicle or MRS2500 to assess fluid secretion by organoid swelling over time. Results: Rotavirus-infected pups exhibited significant diarrhea incidence and high diarrhea scores on days 2, 3, and 4 post infection. Treatment of rotavirus-infected mouse pups with MRS2500 resulted in decreased severity and incidence of diarrhea compared to vehicle treated controls. This was consistent with in vitro, rD6/2-infected organoids exhibiting a significant increase in organoid swelling compared to uninfected organoids, which was significantly prevented by inhibition of P2Y1 signaling. Viral stool shedding from MRS2500 treated pups was significantly lower than saline-treated pups starting at day 4 post infection, which suggests P2Y1 signaling may amplify rotavirus replication in vivo. Finally, transmission experiments in litters with infected (but not treated) and pretreated MRS2500 uninfected pups show a decreased incidence in diarrhea suggesting that P2Y1 inhibition has a potential protective role in reducing the effects of transmission. Conclusion: Collectively these findings establish a conserved role of purinergic signaling in the pathophysiology of rotavirus infection. Additionally, our data indicates P2Y1 as a new candidate for host-targeted therapeutics that could have both antiviral and antidiarrheal effects against rotavirus pathophysiology. R01 DK115507 (Hyser) R01 AI158683 (Hyser)APS Postdoctoral Fellowship (Engevik) F32 DK130288 (Engevik). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.