@article{8f22dabc286a4b0abbc0c5ee6c320ab4,
title = "Small Bowel Resection Increases Paracellular Gut Barrier Permeability via Alterations of Tight Junction Complexes Mediated by Intestinal TLR4",
abstract = "Background: Short bowel syndrome resulting from small bowel resection (SBR) is associated with significant morbidity and mortality. Many adverse sequelae including steatohepatitis and bacterial overgrowth are thought to be related to increased bacterial translocation, suggesting alterations in gut permeability. We hypothesized that after intestinal resection, the intestinal barrier is altered via toll-like receptor 4 (TLR4) signaling at the intestinal level. Methods: B6 and intestinal-specific TLR4 knockout (iTLR4 KO) mice underwent 50% SBR or sham operation. Transcellular permeability was evaluated by measuring goblet cell associated antigen passages via two-photon microscopy. Fluorimetry and electron microscopy evaluation of tight junctions (TJ) were used to assess paracellular permeability. In parallel experiments, single-cell RNA sequencing measured expression of intestinal integral TJ proteins. Western blot and immunohistochemistry confirmed the results of the single-cell RNA sequencing. Results: There were similar number of goblet cell associated antigen passages after both SBR and sham operation (4.5 versus 5.0, P > 0.05). Fluorescein isothiocyanate–dextran uptake into the serum after massive SBR was significantly increased compared with sham mice (2.13 ± 0.39 ng/μL versus 1.62 ± 0.23 ng/μL, P < 0.001). SBR mice demonstrated obscured TJ complexes on electron microscopy. Single-cell RNA sequencing revealed a decrease in TJ protein occludin (21%) after SBR (P < 0.05), confirmed with immunostaining and western blot analysis. The KO of iTLR4 mitigated the alterations in permeability after SBR. Conclusions: Permeability after SBR is increased via changes at the paracellular level. However, these alterations were prevented in iTLR4 mice. These findings suggest potential protein targets for restoring the intestinal barrier and obviating the adverse sequelae of short bowel syndrome.",
keywords = "Gut permeability, Intestinal barrier, Intestinal resection, Mice, Short gut, TLR4, Tight junction",
author = "Courtney, {Cathleen M.} and Onufer, {Emily J.} and McDonald, {Keely G.} and Steinberger, {Allie E.} and Sescleifer, {Anne M.} and Seiler, {Kristen M.} and Tecos, {Maria E.} and Newberry, {Rodney D.} and Warner, {Brad W.}",
note = "Funding Information: The authors thank Jun Guo from the Warner laboratory for his assistance in planning the methodology for paracellular permeability, Karen Green at the electron microscopy core for her assistance in providing fixative and embedding the specimens, Keely McDonald from the Newberry laboratory for providing the protocol and quantification of goblet cell associated antigen passages, and the Washington University developmental biology core and digestive diseases research core for the processing and staining of histological samples. Authors' contributions, C.M.C. contributed to experimental design, mouse resections/animal care, transgenic induction, permeability studies, intestinal harvest/isolation, EM analysis, RNA/protein expression analysis, and MRI analysis. E.J.O. contributed to mouse resections/animal care. K.G.McD. contributed to transcellular GAPS imaging. A.E.S. contributed to intestinal harvest/isolation and MRI analysis. A.M.S. contributed to permeability studies, RNA/protein extraction and expression analysis. K.M.S. contributed to RNA sequencing. M.E.T contributed to intestinal harvest. R.D.N. contributed to transcellular GAPS quantification. Funding sources, C.M.C. received funding from Children's Hope Foundation–Marion and Van Black Research Scholar. E.J.O, A.E.S. and A.M.S. received funding from NIH 5T32DK077653. K.M.S received funding from NIH 5T32HD043010. M.E.T received funding from NIH T32DK007120. R.D.N. received funding from NIH 5R01AI136515. B.W.W. received funding from NIH 5R01DK119147, Children's Surgical Sciences Research Institute of the St. Louis Children's Hospital Foundation, Marion, and Van Black Research Scholarship. Funding Information: C.M.C. received funding from Children's Hope Foundation–Marion and Van Black Research Scholar . E.J.O, A.E.S., and A.M.S. received funding from NIH 5T32DK077653 . K.M.S received funding from NIH 5T32HD043010. M.E.T received funding from NIH T32DK007120. R.D.N. received funding from NIH 5R01AI136515. B.W.W. received funding from NIH 5R01DK119147, Children's Surgical Sciences Research Institute of the St. Louis Children's Hospital Foundation, Marion, and Van Black Research Scholarship. Publisher Copyright: {\textcopyright} 2020 Elsevier Inc.",
year = "2021",
month = feb,
doi = "10.1016/j.jss.2020.08.049",
language = "English",
volume = "258",
pages = "73--81",
journal = "Journal of Surgical Research",
issn = "0022-4804",
}