Hyaluronan 35 kDa treatment protects mice from Citrobacter rodentium infection and induces epithelial tight junction protein ZO-1 in vivo

Abstract

Maintaining a healthy intestinal barrier, the primary physical barrier between intestinal microbiota and the underlying lamina propria, is critical for optimal health. Epithelial integrity is essential for prevention of the entrance of luminal contents, such as bacteria and their products, through the large intestinal barrier. In this study, we investigated the protective functions of biosynthetic, specific sized, hyaluronan around 35 kDa (HA35) on intestinal epithelium in healthy mice, as well as mice infected Citrobacter rodentium, an established model that mimics infection with a serious human pathogen, enteropathogenic E. coli (EPEC). Our results reveal that treatment with HA35 protects mice from Citrobacter infection and enhances the epithelial barrier function. In particular, we have found that HA35 induces the expression of tight junction protein zonula occludens (ZO)-1 in both healthy and Citrobacter infected mice, as demonstrated by immunoflurorescence and Western blot analyses. Furthermore, we determined that HA35 treatment enhances ZO-1 expression and reduces intestinal permeability at the early stages of dextran sulfate sodium (DSS)-induced colitis in mice. Together, our data demonstrate that the expression and functionality of tight junctions, is increased by HA35 treatment, suggesting a novel mechanism for the protection from Citrobacter infection.

MicroRNA 181b‐3p and its target importin α5 regulate toll‐like receptor 4 signaling in Kupffer cells and liver injury in mice in response to ethanol

“…(33) HA35 upregulates ZO-1 in mice undergoing Citrobacter rodentium infection, associated with protection from C rodentium infection in vivo. (24) Although our data from Kupffer cells indicates that HA35 has direct effects on inflammatory signaling in Kupffer cells, it is also possible that HA35 treatment in mice during ethanol feeding has direct and/or indirect protective effects on the intestine. Dietary HA is absorbed and migrates to the skin and other organs, and is then excreted in the urine and feces.…”

“…(21) IMMUNOHISTOCHEMISTRY Formalin (liver) or Histochoice (proximal colon)fixed paraffin-embedded sections were deparaffinized and used to assess M30 cytoDEATH (Roche, 12140322), terminal deoxynucleotidyl transferasemediated deoxyuridine triphosphate nick-end labeling (TUNEL) (Merck Millipore, S7111), and phosphorylated p65 (phospho-p65) in the liver (23) or ZO-1 and occludin in the proximal colon. (24) Staining for Oil Red O was performed using sections cut from frozen liver in OCT. Nuclei were labeled using Vectashield with DAPI or hematoxylin.…”

Specifically Sized Hyaluronan (35 kDa) Prevents Ethanol‐Induced Disruption of Epithelial Tight Junctions Through a layilin‐Dependent Mechanism in Caco‐2 Cells

“…EtOH‐induced disruption of intestinal barrier function is an important contributor to the pathophysiological mechanisms for alcohol‐induced liver and tissue injury. HA35, a small specific‐sized hyaluronan species, has protective effects on intestinal homeostasis in both development and disease (Hill et al., ; Kim et al., ). Importantly, oral provision of HA35 during short‐term EtOH feeding to mice prevented EtOH‐induced loss of tight junction integrity in the proximal colon, reduced the concentration of endotoxin in the portal circulation, and protected from liver injury (Saikia et al., ).…”

“…Immunofluorescent staining of tight junction proteins in the jejunum, ileum, proximal colon, and distal colon (Kim et al., ) and Caco‐2 monolayers (Rezaee et al., ) was performed. Paraffin‐embedded intestinal sections were deparaffinized.…”

“…For example, hyaluronan is a component of breast milk and contributes to the establishment of intestinal health in newborns (de la Motte and Kessler, ; Hill et al., ). Further, specific‐sized hyaluronan of an average molecular weight of 35kD (HA35) protects mice from Salmonella (Kessler et al., )‐ and Citrobacter (Kim et al., )‐mediated disruption of the intestinal barrier and induces the expression of zonula occludens‐1 (ZO‐1).…”