scholarly journals Intestinal Bacteroides Modulates Systemic Inflammation and the Microbial Ecology in a Mouse Model of CF: Evidence for Propionate and other Short Chain Fatty Acids Reducing Systemic Inflammatory Cytokines

2022 ◽  
Author(s):  
Courtney Price ◽  
Rebecca Valls ◽  
Alexis Ramsey ◽  
Nicole Loeven ◽  
Jane Jones ◽  
...  

Persons with cystic fibrosis, starting in early life, have intestinal microbiome dysbiosis characterized in part by a decreased relative abundance of the genus Bacteroides. Bacteroides is a major producer of the intestinal short chain fatty acid (SCFA) propionate. We demonstrate here that CFTR-/- Caco-2 intestinal epithelial cells are responsive to the anti-inflammatory effects of propionate. Furthermore, Bacteroides isolates inhibit the IL-1β-induced inflammatory response of CFTR-/- Caco-2 intestinal epithelial cells and do so in a propionate-dependent manner. Bacteroides isolates also produce low levels of butyrate; this SCFA is positively correlated with inhibition of the inflammatory response. Finally, the introduction of Bacteroides-supplemented stool from infants with CF into the gut of CftrF508del mice results in an increase in propionate in the stool as well as the reduction in several systemic pro-inflammatory cytokines. Bacteroides supplementation also reduced the fecal relative abundance of E. coli, indicating a potential interaction between these two microbes, consistent with previous clinical studies. Together, our data indicate the important role of Bacteroides and Bacteroides-derived propionate in the context of the developing microbiome in infants and children with CF, which could help explain the observed gut-lung axis in CF.

1998 ◽  
Vol 275 (1) ◽  
pp. E55-E63 ◽  
Author(s):  
Akiyoshi Nishimura ◽  
Mika Fujimoto ◽  
Satoshi Oguchi ◽  
Robert D. Fusunyan ◽  
Richard P. MacDermott ◽  
...  

Gastrointestinal epithelial cells secrete insulin-like growth factor (IGF)-binding proteins (IGFBPs), which modulate the actions of IGFs on cell proliferation and differentiation. Short-chain fatty acids are bacterial metabolites from unabsorbed carbohydrate (including fiber). We hypothesized that they may alter the pattern of IGFBPs secreted by epithelial cells as part of a wider phenomenon by which luminal molecules regulate gastrointestinal epithelial cell signaling. The intestinal epithelial cell line, Caco-2, predominantly secretes IGFBP-3; however, butyrate increased the secretion of IGFBP-2 in a dose-dependent and reversible manner. Butyrate decreased the secretion of IGFBP-3. Butyrate altered only the synthesis and not the cell sorting of IGFBPs because 1) the secretion of IGFBPs remained polarized despite changes in their rates of production, and 2) IGFBP secretion corresponded to mRNA accumulation. The ability of short-chain fatty acids or the fungicide trichostatin A to stimulate IGFBP-2 correlated with their actions on histone acetylation. In conclusion, intestinal epithelial cells respond to short-chain fatty acids by altering secretion of IGFBPs.


2016 ◽  
Vol 310 (7) ◽  
pp. C542-C557 ◽  
Author(s):  
Jia Wang ◽  
Liang Han ◽  
James Sinnett-Smith ◽  
Li-Li Han ◽  
Jan V. Stevens ◽  
...  

Given the fundamental role of β-catenin signaling in intestinal epithelial cell proliferation and the growth-promoting function of protein kinase D1 (PKD1) in these cells, we hypothesized that PKDs mediate cross talk with β-catenin signaling. The results presented here provide several lines of evidence supporting this hypothesis. We found that stimulation of intestinal epithelial IEC-18 cells with the G protein-coupled receptor (GPCR) agonist angiotensin II (ANG II), a potent inducer of PKD activation, promoted endogenous β-catenin nuclear localization in a time-dependent manner. A significant increase was evident within 1 h of ANG II stimulation ( P < 0.01), peaked at 4 h ( P < 0.001), and declined afterwards. GPCR stimulation also induced a marked increase in β-catenin-regulated genes and phosphorylation at Ser552 in intestinal epithelial cells. Exposure to preferential inhibitors of the PKD family (CRT006610 or kb NB 142-70) or knockdown of the isoforms of the PKD family prevented the increase in β-catenin nuclear localization and phosphorylation at Ser552 in response to ANG II. GPCR stimulation also induced the formation of a complex between PKD1 and β-catenin, as shown by coimmunoprecipitation that depended on PKD1 catalytic activation, as it was abrogated by cell treatment with PKD family inhibitors. Using transgenic mice that express elevated PKD1 protein in the intestinal epithelium, we detected a marked increase in the localization of β-catenin in the nucleus of crypt epithelial cells in the ileum of PKD1 transgenic mice, compared with nontransgenic littermates. Collectively, our results identify a novel cross talk between PKD and β-catenin in intestinal epithelial cells, both in vitro and in vivo.


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