BACKGROUND: The intestinal epithelium, with the potential to restrict luminal noxae from the host, secretes a mucous layer with various protective functions. Microbial colonization of germfree (GF) rats stimulates this mucin-secreting tissue. The present study determined the effect of bacterial lipopolysaccharides (LPS) on this process. METHODS: One, 3, and 5 days after peroral application of 35 micrograms LPS/100 g body weight (from Escherichia coli O55:B5), LPS concentrations were monitored in ingesta, intestinal tissue, and liver. Mucin high molecular weight glycoproteins (HMG), released in response to LPS, were isolated and separated into mucins, i) attached to the colonic epithelium (EM) and ii) mixed to the luminal content (LM), respectively. Subsequently, the binding capacity of both mucin fractions for various lectins and for type-1 pili expressing E. coli was determined. RESULTS: Ingesta and tissue had maximal LPS concentrations on days 3 (jejunum) and 5 (colon). Maximal EM secretion was found on day 3, release of LM further increased to day 5. Both mucin fractions had altered glycosylation patterns: augmentation of beta-galactose, alpha-N-acetyl galactosamine, and mannose coincided with a decrease in alpha-fucose. Compared with the controls, attachment of E. coli to EM increased slightly on day 1 only; the binding capacity of LM increased continuously up to day 5. CONCLUSION: Results suggest that mucins, released in response to LPS, in addition to the epithelial protection, support the gut microbial clearance system.
BACKGROUND: The intestinal epithelium, with the potential to restrict luminal noxae from the host, secretes a mucous layer with various protective functions. Microbial colonization of germfree (GF) rats stimulates this mucin-secreting tissue. The present study determined the effect of bacterial lipopolysaccharides (LPS) on this process. METHODS: One, 3, and 5 days after peroral application of 35 micrograms LPS/100 g body weight (from Escherichia coli O55:B5), LPS concentrations were monitored in ingesta, intestinal tissue, and liver. Mucin high molecular weight glycoproteins (HMG), released in response to LPS, were isolated and separated into mucins, i) attached to the colonic epithelium (EM) and ii) mixed to the luminal content (LM), respectively. Subsequently, the binding capacity of both mucin fractions for various lectins and for type-1 pili expressing E. coli was determined. RESULTS: Ingesta and tissue had maximal LPS concentrations on days 3 (jejunum) and 5 (colon). Maximal EM secretion was found on day 3, release of LM further increased to day 5. Both mucin fractions had altered glycosylation patterns: augmentation of beta-galactose, alpha-N-acetyl galactosamine, and mannose coincided with a decrease in alpha-fucose. Compared with the controls, attachment of E. coli to EM increased slightly on day 1 only; the binding capacity of LM increased continuously up to day 5. CONCLUSION: Results suggest that mucins, released in response to LPS, in addition to the epithelial protection, support the gut microbial clearance system.
Authors: J Petersson; O Schreiber; G C Hansson; S J Gendler; A Velcich; J O Lundberg; S Roos; L Holm; M Phillipson Journal: Am J Physiol Gastrointest Liver Physiol Date: 2010-11-25 Impact factor: 4.052
Authors: Kirk S B Bergstrom; Vanessa Kissoon-Singh; Deanna L Gibson; Caixia Ma; Marinieve Montero; Ho Pan Sham; Natasha Ryz; Tina Huang; Anna Velcich; B Brett Finlay; Kris Chadee; Bruce A Vallance Journal: PLoS Pathog Date: 2010-05-13 Impact factor: 6.823
Authors: Kyo-Sang Yoo; Ho Soon Choi; Dae Won Jun; Hang Lak Lee; Oh Young Lee; Byung Chul Yoon; Kyeong Geun Lee; Seung Sam Paik; Yong Seok Kim; Jin Lee Journal: Gut Liver Date: 2016-09-15 Impact factor: 4.519