Caveolin-1 and Tight Junction Expression in Human Intestine as a Susceptibility Marker of Necrotizing Enterocolitis

Abstract

INTRODUCTION: Necrotizing enterocolitis (NEC) is a devastating disease of prematurity. NEC has been associated with increased intestinal epithelium permeability due to dysregulation of tight junction (TJ) proteins. Caveolin-1 is a ubiquitous membrane protein that is involved in cellular membrane maintenance by aiding in TJ assembly. We hypothesize that baseline levels of caveolin-1 differ in patients with NEC when compared to patients without NEC. METHODS: Human intestinal tissue was collected from patient samples during the time of operation. Patients were all preterm (<37 weeks) infants who underwent exploratory laparotomy for either NEC or non-NEC sources. University of Oklahoma Health Sciences Center IRB approval (#11611) and informed consent were obtained. Specimens were collected, deidentified, and stored. Specimens were paraffin embedded, stained, and imaged by immunofluorescence. Western blot analysis was performed on protein isolates. RESULTS: Infant intestinal tissue demonstrated a relative decreased expression of epithelial caveolin-1 in NEC tissues compared with controls. A nuclear stain (4′,6-diamidino-2-phenylindole) was used in conjunction with anti–caveolin-1 Ab to visualize caveolin expression in the intestinal mucosa. There is an increased concentration of caveolin-1 in patients without history of NEC (Fig. 1a). Western blot of intestinal tissue also revealed diminished caveolin-1 protein in patients with NEC (Fig. 1b). These data correlate with a decrease in the TJ occluding in patients with NEC (Fig. 1c).Figure 1CONCLUSION: We conclude that decreased caveolin-1 levels in intestinal epithelium may increase susceptibility to the development of necrotizing enterocolitis. This may be caused by a decrease intestinal TJ assembly and increased permeability of the intestinal epithelium.