Limits...
TNFAIP3 maintains intestinal barrier function and supports epithelial cell tight junctions.

Kolodziej LE, Lodolce JP, Chang JE, Schneider JR, Grimm WA, Bartulis SJ, Zhu X, Messer JS, Murphy SF, Reddy N, Turner JR, Boone DL - PLoS ONE (2011)

Bottom Line: In cultured human intestinal epithelial cell lines, TNFAIP3 expression regulated both TNF-induced and myosin light chain kinase-regulated tight junction dynamics but did not affect myosin light chain kinase activity.We also found that TNFAIP3 deubiquitinates polyubiquitinated occludin.These in vivo and in vitro studies support the role of TNFAIP3 in promoting intestinal epithelial barrier integrity and demonstrate its novel ability to maintain intestinal homeostasis through tight junction protein regulation.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Chicago, Chicago, Illinois, United States of America.

ABSTRACT
Tight junctions between intestinal epithelial cells mediate the permeability of the intestinal barrier, and loss of intestinal barrier function mediated by TNF signaling is associated with the inflammatory pathophysiology observed in Crohn's disease and celiac disease. Thus, factors that modulate intestinal epithelial cell response to TNF may be critical for the maintenance of barrier function. TNF alpha-induced protein 3 (TNFAIP3) is a cytosolic protein that acts in a negative feedback loop to regulate cell signaling induced by Toll-like receptor ligands and TNF, suggesting that TNFAIP3 may play a role in regulating the intestinal barrier. To investigate the specific role of TNFAIP3 in intestinal barrier function we assessed barrier permeability in TNFAIP3(-/-) mice and LPS-treated villin-TNFAIP3 transgenic mice. TNFAIP3(-/-) mice had greater intestinal permeability compared to wild-type littermates, while villin-TNFAIP3 transgenic mice were protected from increases in permeability seen within LPS-treated wild-type littermates, indicating that barrier permeability is controlled by TNFAIP3. In cultured human intestinal epithelial cell lines, TNFAIP3 expression regulated both TNF-induced and myosin light chain kinase-regulated tight junction dynamics but did not affect myosin light chain kinase activity. Immunohistochemistry of mouse intestine revealed that TNFAIP3 expression inhibits LPS-induced loss of the tight junction protein occludin from the apical border of the intestinal epithelium. We also found that TNFAIP3 deubiquitinates polyubiquitinated occludin. These in vivo and in vitro studies support the role of TNFAIP3 in promoting intestinal epithelial barrier integrity and demonstrate its novel ability to maintain intestinal homeostasis through tight junction protein regulation.

Show MeSH

Related in: MedlinePlus

TNFAIP3 supports occludin localization at intestinal tight junctions.Immunohistochemistry for occludin (green), actin (red) and DNA (blue) is shown in intestines of untreated wild type (WT) and TNFAIP3−/− mice. A lack of typical perijunctional occludin localization can be observed at the apical surface of epithelial cells in the TNFAIP3 deficient mice.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3198775&req=5

pone-0026352-g001: TNFAIP3 supports occludin localization at intestinal tight junctions.Immunohistochemistry for occludin (green), actin (red) and DNA (blue) is shown in intestines of untreated wild type (WT) and TNFAIP3−/− mice. A lack of typical perijunctional occludin localization can be observed at the apical surface of epithelial cells in the TNFAIP3 deficient mice.

Mentions: Factors that modulate IEC response to TNF may be critical for the maintenance of barrier function [10]. TNFAIP3 inhibits TNF-induced signaling pathways; therefore, we examined whether TNFAIP3 plays a central role in regulating IEC barrier permeability. To investigate the role of TNFAIP3 in maintaining the intestinal barrier we assessed barrier integrity in TNFAIP3−/− mice. These mice spontaneously develop inflammation that is driven by TLR-dependent signals originating from endogenous microbiota [17], [19], [39]. Immunohistochemistry for the intestinal epithelial tight junction protein occludin revealed characteristic morphological features of epithelial tight junction disruption, including the loss of occludin localization from the apical surface in intestinal tissue taken from unperturbed TNFAIP3−/− mice (Figure 1). Further evidence for epithelial tight junction disruption was observed when measuring flux of FITC-dextran out of explanted intestinal loops from TNFAIP3−/− mice compared with that of wild-type (WT) mice. WT mice showed a minimal change in flux over time indicating an intact intestinal barrier, while TNFAIP3−/− mice had a more pronounced increase in flux indicating greater intestinal permeability in these mice (Figure 2). Thus, TNFAIP3 is required for the maintenance of intestinal barrier function in vivo. As TNFAIP3 normally restricts inflammatory TLR signals and its expression is induced in a variety of tissue types [17], [19], [39], the increased gut permeability in TNFAIP3−/− mice might reflect an indirect effect of ongoing inflammation in these mice, a direct role for TNFAIP3 in IEC TJ stability, or a combination of these two effects.


TNFAIP3 maintains intestinal barrier function and supports epithelial cell tight junctions.

Kolodziej LE, Lodolce JP, Chang JE, Schneider JR, Grimm WA, Bartulis SJ, Zhu X, Messer JS, Murphy SF, Reddy N, Turner JR, Boone DL - PLoS ONE (2011)

TNFAIP3 supports occludin localization at intestinal tight junctions.Immunohistochemistry for occludin (green), actin (red) and DNA (blue) is shown in intestines of untreated wild type (WT) and TNFAIP3−/− mice. A lack of typical perijunctional occludin localization can be observed at the apical surface of epithelial cells in the TNFAIP3 deficient mice.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198775&req=5

pone-0026352-g001: TNFAIP3 supports occludin localization at intestinal tight junctions.Immunohistochemistry for occludin (green), actin (red) and DNA (blue) is shown in intestines of untreated wild type (WT) and TNFAIP3−/− mice. A lack of typical perijunctional occludin localization can be observed at the apical surface of epithelial cells in the TNFAIP3 deficient mice.
Mentions: Factors that modulate IEC response to TNF may be critical for the maintenance of barrier function [10]. TNFAIP3 inhibits TNF-induced signaling pathways; therefore, we examined whether TNFAIP3 plays a central role in regulating IEC barrier permeability. To investigate the role of TNFAIP3 in maintaining the intestinal barrier we assessed barrier integrity in TNFAIP3−/− mice. These mice spontaneously develop inflammation that is driven by TLR-dependent signals originating from endogenous microbiota [17], [19], [39]. Immunohistochemistry for the intestinal epithelial tight junction protein occludin revealed characteristic morphological features of epithelial tight junction disruption, including the loss of occludin localization from the apical surface in intestinal tissue taken from unperturbed TNFAIP3−/− mice (Figure 1). Further evidence for epithelial tight junction disruption was observed when measuring flux of FITC-dextran out of explanted intestinal loops from TNFAIP3−/− mice compared with that of wild-type (WT) mice. WT mice showed a minimal change in flux over time indicating an intact intestinal barrier, while TNFAIP3−/− mice had a more pronounced increase in flux indicating greater intestinal permeability in these mice (Figure 2). Thus, TNFAIP3 is required for the maintenance of intestinal barrier function in vivo. As TNFAIP3 normally restricts inflammatory TLR signals and its expression is induced in a variety of tissue types [17], [19], [39], the increased gut permeability in TNFAIP3−/− mice might reflect an indirect effect of ongoing inflammation in these mice, a direct role for TNFAIP3 in IEC TJ stability, or a combination of these two effects.

Bottom Line: In cultured human intestinal epithelial cell lines, TNFAIP3 expression regulated both TNF-induced and myosin light chain kinase-regulated tight junction dynamics but did not affect myosin light chain kinase activity.We also found that TNFAIP3 deubiquitinates polyubiquitinated occludin.These in vivo and in vitro studies support the role of TNFAIP3 in promoting intestinal epithelial barrier integrity and demonstrate its novel ability to maintain intestinal homeostasis through tight junction protein regulation.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Chicago, Chicago, Illinois, United States of America.

ABSTRACT
Tight junctions between intestinal epithelial cells mediate the permeability of the intestinal barrier, and loss of intestinal barrier function mediated by TNF signaling is associated with the inflammatory pathophysiology observed in Crohn's disease and celiac disease. Thus, factors that modulate intestinal epithelial cell response to TNF may be critical for the maintenance of barrier function. TNF alpha-induced protein 3 (TNFAIP3) is a cytosolic protein that acts in a negative feedback loop to regulate cell signaling induced by Toll-like receptor ligands and TNF, suggesting that TNFAIP3 may play a role in regulating the intestinal barrier. To investigate the specific role of TNFAIP3 in intestinal barrier function we assessed barrier permeability in TNFAIP3(-/-) mice and LPS-treated villin-TNFAIP3 transgenic mice. TNFAIP3(-/-) mice had greater intestinal permeability compared to wild-type littermates, while villin-TNFAIP3 transgenic mice were protected from increases in permeability seen within LPS-treated wild-type littermates, indicating that barrier permeability is controlled by TNFAIP3. In cultured human intestinal epithelial cell lines, TNFAIP3 expression regulated both TNF-induced and myosin light chain kinase-regulated tight junction dynamics but did not affect myosin light chain kinase activity. Immunohistochemistry of mouse intestine revealed that TNFAIP3 expression inhibits LPS-induced loss of the tight junction protein occludin from the apical border of the intestinal epithelium. We also found that TNFAIP3 deubiquitinates polyubiquitinated occludin. These in vivo and in vitro studies support the role of TNFAIP3 in promoting intestinal epithelial barrier integrity and demonstrate its novel ability to maintain intestinal homeostasis through tight junction protein regulation.

Show MeSH
Related in: MedlinePlus