Caveolin-1-Mediated Tight Junction Assembly and Intestinal Permeability in Necrotizing Enterocolitis

Introduction: Necrotizing Enterocolitis (NEC) is a gastrointestinal emergency in premature neonates. Its multifactorial pathogenesis includes increased permeability and dysregulated inflammation. Caveolin-1 regulates intestinal permeability via endocytosis and trafficking of tight junction proteins, specifically occludin. We hypothesize that caveolin-1 expression is altered in NEC leading to decreased tight junction protein trafficking and increased intestinal permeability. Methods: Wild-type and caveolin-1 knockout mice underwent experimental NEC for survival analysis followed by tissue harvest for histologic evaluation, permeability assay, RNA and protein extraction, immunohistochemistry, and enteroid generation. Enteroids derived from wild-type and caveolin-1 knockout mice underwent experimental NEC followed by permeability assay and RNA extraction for RT-qPCR. Additionally, tissue from human patients with and without active NEC underwent protein extraction for western blot and immunofluorescent staining. Results: Caveolin-1 knockout mice had worsened experimental NEC on gross and histologic analysis compared to wild-type and decreased survival (p<0.05,p=0.003). Caveolin-1 knockout enteroids had increased permeability following experimental NEC (p=0.022, p=0.006). Occludin localization was more disorganized and expression was decreased in experimental caveolin-1 knockout mice compared to wild-type (p=0.002). Caveolin-1 and occludin protein was found to be decreased in active human NEC tissue compared to control (p=0.004, p=0.025). Conclusion: Caveolin-1 deficiency is associated with decreased survival and more severe histologic disease in a mouse model of NEC. Caveolin-1 expression is decreased in NEC, which correlates with a decrease in occludin expression and resultant increase in intestinal permeability. Our work suggests caveolin-1 deficiency may lead to a predisposition to increased permeability in response to NEC.