The RNA-binding protein Imp1 promotes a Spdef transcriptional program and enhances goblet cell response to necrotizing enterocolitis

Background: In the United States over 10% of all neonates are born premature (less than 37 weeks gestational age), and many face complications, such as necrotizing enterocolitis (NEC). NEC is the most deadly gastrointestinal disease in preterm neonates with up to 50% mortality. Survivors face lifelong complications. NEC is a multifactorial disease caused in part by intestinal immaturity, including a poorly developed physical barrier between luminal contents and the rest of the body, leading to irreparable damage to the intestine. Since there is no cure for NEC, prevention is the best strategy. Enhancing our understanding of intestinal epithelial cell [IEC] barrier regulation during early development will provide novel therapeutic targets to prevent NEC. Published evidence indicates roles for the RNA-binding protein insulin-like growth factor 2 mRNA binding protein 1 (IMP1) in intestinal development, barrier function, and intestinal repair. Sequencing data from the inflamed tissue of a NEC patient indicates that IMP1 is down-regulated relative to uninflamed tissue. Notably, roles for IMP1 in NEC are not defined. Goblet cells produce protective mucus in the intestine, and their mature function is dependent on the transcription factor Spdef. Emerging evidence suggests that goblet cell mucus complexity impacts barrier function and inflammation susceptibility. This study aimed to define the role of IMP1 in NEC pathogenesis using a model of NEC-like intestinal injury in mice with IEC-specific Imp1 overexpression. Hypothesis: IMP1 expression is protective in a mouse model of NEC. Methods: All studies are OHSU IACUC-approved. This study used wildtype (WT, control) and Imp1 IEC-overexpression (VillinCre;lslFLAG-Imp1OE; Imp1IEC-OE) mice. At post-natal day 3, mice of both sexes were randomly assigned to control or NEC groups. The control mice remained with the dam. NEC was induced with the well-established experimental NEC-like intestinal injury model. Mice were separated from the dam and maintained in an incubator. Pups were gavage-fed a mixture of infant formula, puppy replacer, bacteria derived from a premature infant with NEC, and 2.5 ug/g body weight of lipopolysaccharide every 3 hours from 7:30 am-10 pm. Twice daily, the pups were exposed to hypoxia (5% oxygen). After 72 hours, tissue was collected for histology, gene, and protein expression analyses. Total RNA sequencing was performed using the NovaSeq S4. Goblet cells were evaluated by immunostaining. Statistical analyses were performed using 2-way ANOVA with Tukey’s test for multiple comparisons. Results: The NEC model induces pneumatosis, histological damage, and a significant up-regulation of inflammatory cytokine gene expression Lcn2 and Il1B, p< 0.05, n=30-31. Pathway analysis of RNA sequencing data revealed a unique and significant enrichment of Spdef transcriptional activity in Imp1IEC-OE during NEC. This included significant upregulation of Spdef target genes such as, Agr2 (in NEC WT: 617.8 +/- 33.56 vs Imp1IEC-OE: 812.9 +/- 111.3, p=0.02) and Fut2 (in NEC WT: 219.4 +/- 34 vs Imp1IEC-OE: 396.6 +/- 62.9, p=0.05). In silico analysis predicted Imp1 binding to Spdef mRNA. Although genotype did not affect goblet cell number, Imp1IEC-OE mice with NEC exhibited significant increases (p< 0.05) in genes responsible for goblet cell function (Spink4, Klk1, Tspg1) mucus glycosylation (Gcnt3, B3gnt7, Qsox1), and mucus secretion (Creb3l4, Ramp1, Chrm1). Conclusion: Our data indicate that during NEC, Imp1 may enhance goblet cell function via Spdef. Ongoing studies will examine mucus glycosylation and secretion, and assess Imp1 binding targets. Funding: NIH K01DK129401, R01HD097367, R03DK142841-01, the Gerber Foundation This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.