542 - Piezo1 expression is associated with inflammation mediated gut injury

Poster Number: 542
Publication Number: 542.2232

Background: Preterm birth remains the leading cause of mortality for children < 5 years of age worldwide, with necrotizing enterocolitis (NEC) the leading cause of mortality (20-50%). The impaired mucosal barrier and underdeveloped innate immunity in preterm infants make them particularly susceptible to intestinal injury. Piezo1 is a mechanosensitive channel essential for maintaining the intestinal epithelial barrier and regulating innate immunity. Despite its broad expression across the numerous intestinal layers, its specific expression and role in the developing gut and inflammation-mediated gut injury have yet to be elucidated.

Objective: This project aimed to define Piezo1 gene expression and localization in the developing gut of mice from early embryonic age into adulthood, as well as the impact of Piezo1 expression during intestinal injury/inflammation. We hypothesized that Piezo1 is necessary for epithelial morphogenesis of the neonatal gut. We further hypothesized that Piezo1 expression will be directly associated with the development of sepsis in neonatal murine pups.

Design/Methods: Time-dated C57BL/6 mouse pups were extracted at multiple embryological (E) and postnatal (P) ages (E14.5-P56). Neonatal pups at P7 were then subjected to experimental sepsis by administering 3.00x107 CFU/ml of NECteria (mixed enteric bacteria extracted from a neonate that died from NEC) or sterile normal saline (sham control) via intraperitoneal injection. Distal ileal segments were then processed for Piezo1 mRNA levels, quantified using droplet digital PCR, and localized within the intestinal structures using RNAscope.

Results: Piezo1 mRNA expression (n = 6-8/group) was highest at E14.5 and then significantly decreased in an age-dependent manner until P56 (p < 0.0001). Sepsis-exposed pups at P7 died at an average of 5-6 hours post-inoculation, while sham control pups remained healthy and active for the entire protocol. Piezo1 levels were significantly elevated in the distal ileal segments of mouse pups with experimental sepsis (n=11) compared to sham controls (n=13) (9.15 vs 15.09 copies/ng; p=.0003). This was further correlated using RNAscope, suggesting an overall increase in Piezo1 expression across both the epithelial and muscularis layers of the gut.

Conclusion(s): Our data suggests that Piezo1 is expressed in a developmentally dependent manner and up-regulated during sepsis/intestinal inflammation, making it a potentially critical therapeutic target. Further studies are needed to elucidate the signaling mechanisms driving these processes and the role
of Piezo1 in gut injury-mediated sepsis and NEC.