Hyaluronic Acid 35 kDa Protects against a Hyperosmotic, Formula Feeding Model of Necrotizing Enterocolitis

Abstract

Necrotizing enterocolitis (NEC), an inflammatory disease of the intestine, is a common gastrointestinal emergency among preterm infants. Intestinal barrier dysfunction, hyperactivation of the premature immune system, and dysbiosis are thought to play major roles in the disease. Human milk (HM) is protective, but the mechanisms underpinning formula feeding as a risk factor in the development of NEC are incompletely understood. Hyaluronic acid 35 kDa (HA35), a bioactive glycosaminoglycan of HM, accelerates intestinal development in murine pups during homeostasis. In addition, HA35 prevents inflammation-induced tissue damage in pups subjected to murine NEC, incorporating Paneth cell dysfunction and dysbiosis. We hypothesized HA35 treatment would reduce histological injury and mortality in a secondary mouse model of NEC incorporating formula feeding. NEC-like injury was induced in 14-day mice by dithizone-induced disruption of Paneth cells and oral gavage of rodent milk substitute. Mortality and histological injury, serum and tissue cytokine levels, stool bacterial sequencing, and bulk RNA-Seq comparisons were analyzed. HA35 significantly reduced the severity of illness in this model, with a trend toward reduced mortality, while RNA-Seq analysis demonstrated HA35 upregulated genes associated with goblet cell function and innate immunity. Activation of these critical protective and reparative mechanisms of the small intestine likely play a role in the reduced pathology and enhanced survival trends of HA-treated pups subjected to intestinal inflammation in this secondary model of NEC, providing potentially interesting translational targets for the human preterm disease.

A comparative study of the ameliorative effects of hyaluronic acid oligosaccharides and hyaluronic acid on DSS-induced colitis in mice and research on relevant mechanisms

“…Consistent with our results, a previous study showed that hyaluronic acid could prevent dithizone-induced disruption of epithelial tight junctions. 44 Furthermore, in vitro experiments showed that both could restore the TEER value in the Caco-2 monolayer cell injury model, decrease the FD4 flux, and reduce intestinal epithelial permeability. Given that the expression of TJ proteins is dependent upon the MLCK/p-MLC pathway, myosin light chain kinase (MLCK) activation has been found to compromise the epithelial TJ barrier.…”

Clinical Characteristics and Potential Pathogenesis of Cardiac Necrotizing Enterocolitis in Neonates with Congenital Heart Disease: A Narrative Review

“…In addition, ambitious preterm growth targets often necessitate the use of HM fortifiers, increasing the solute concentration of the infant diet. Fortification of HM, based largely on animal studies [ 84 , 85 ], is a suggested risk factor for classical NEC [ 86 ], but the risks associated with increased dietary osmolality may be further extended in the setting of CHD-associated intestinal ischemia [ 87 ]. Cognata et al demonstrated that an exclusively HM diet without fortification has been associated with a significant reduction in NEC risk preceding complex CHD repair [ 83 ].…”

Host defense peptides human β defensin 2 and LL-37 ameliorate murine necrotizing enterocolitis

“…Importantly, these three endpoints are all dysregulated in our lab’s NEC models. 57 , 58 , 60 , 61 , 64 , 70 Our data show that hBD2 is safe as an in vivo treatment in newborn mice with immature intestines. We also demonstrate that oral hBD2 given either before or after NEC induction as well as subcutaneous injection of hBD2 and oral LL-37 after NEC induction significantly decreased NEC injury scores.…”

“…To further determine the relevance of hBD2’s antimicrobial effects on prevention of experimental NEC, we used our recently described modification of the Paneth cell disruption NEC model with formula gavage replacing K. pneumoniae exposure as the second hit of the model. 57 , 58 , 64 Thus, this model does not use the addition of exogenous live bacteria to induce disease. In brief, P14-P16-day-old C57Bl/6J mice were fed a prepared rodent milk substitute formula (RMS) 57 , 58 , 65 1 h before receiving an intraperitoneal injection with dithizone as above, and then every 3 h for a total of four feeds.…”