Heparan sulfate and syndecan-1 are essential in maintaining murine and human intestinal epithelial barrier function
Lars Bode, … , Simon Murch, Hudson H. Freeze
Lars Bode, … , Simon Murch, Hudson H. Freeze
Published December 6, 2007
Citation Information: J Clin Invest. 2008;118(1):229-238. https://doi.org/10.1172/JCI32335.
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Research Article Gastroenterology

Heparan sulfate and syndecan-1 are essential in maintaining murine and human intestinal epithelial barrier function

Abstract

Patients with protein-losing enteropathy (PLE) fail to maintain intestinal epithelial barrier function and develop an excessive and potentially fatal efflux of plasma proteins. PLE occurs in ostensibly unrelated diseases, but emerging commonalities in clinical observations recently led us to identify key players in PLE pathogenesis. These include elevated IFN-γ, TNF-α, venous hypertension, and the specific loss of heparan sulfate proteoglycans from the basolateral surface of intestinal epithelial cells during PLE episodes. Here we show that heparan sulfate and syndecan-1, the predominant intestinal epithelial heparan sulfate proteoglycan, are essential in maintaining intestinal epithelial barrier function. Heparan sulfate– or syndecan-1–deficient mice and mice with intestinal-specific loss of heparan sulfate had increased basal protein leakage and were far more susceptible to protein loss induced by combinations of IFN-γ, TNF-α, and increased venous pressure. Similarly, knockdown of syndecan-1 in human epithelial cells resulted in increased basal and cytokine-induced protein leakage. Clinical application of heparin has been known to alleviate PLE in some patients but its unknown mechanism and severe side effects due to its anticoagulant activity limit its usefulness. We demonstrate here that non-anticoagulant 2,3-de-O-sulfated heparin could prevent intestinal protein leakage in syndecan-deficient mice, suggesting that this may be a safe and effective therapy for PLE patients.

Authors

Lars Bode, Camilla Salvestrini, Pyong Woo Park, Jin-Ping Li, Jeffrey D. Esko, Yu Yamaguchi, Simon Murch, Hudson H. Freeze

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Figure 6

Heparin and 2/3-DS-H alleviate protein leakage in vitro and in mice.

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Heparin and 2/3-DS-H alleviate protein leakage in vitro and in mice. (A)...
(A) Albumin leakage (mean ± SD) through HT29 monolayers relative to untreated cells. Maximum leakage (white bar) was induced by incubating cells with heparinase (HS loss), IFN-γ (10 ng/ml, 24 h), and TNF-α (2 ng/ml, 12 h). Cytokines were coincubated with heparin-like compounds or other GAG derivatives at 2.5 μg/ml or 25.0 μg/ml. Heparin (lane 2) and 2/3-DS-H (lane 9) were most effective in alleviating cytokine-induced protein leakage (arrows). Lane 1, HS; lane 2, high-molecular-weight heparin (unfractionated); lane 3, low-molecular-weight heparin; lane 4, sized heparin, dp 2; lane 5, sized heparin, dp 8; lane 6, sized heparin, dp 14; lane 7, sized heparin, dp 20; lane 8, 2,6-de-O-sulfated heparin; lane 9, 2/3-DS-H; lane 10, 6-O-desulfated heparin (chemical desulfation); lane 11, 6-O-desulfated heparin (enzymatic desulfation with endosulfatase [HSulf2]); lane 12, carboxyl-reduced heparin; lane 13, fully N-acetylated heparin; lane 14, fully O-sulfated N-acetylated heparin; lane 15, chondroitin sulfate; lane 16, fully O-sulfated chondroitin sulfate; lane 17, dermatan sulfate; lane 18, fully O-sulfated dermatan sulfate; lane 19, fully O-sulfated hyaluronic acid; lane 20, archaran sulfate; lane 21, sulfated cyclodextran; lane 22, sucrose octasulfate. (B–G) Intestinal protein leakage in Sdc1+/+ (B, C, E, and F) and Sdc1–/– mice (D and G) assessed by in vivo 51Cr labeling. Mice were injected daily with low (100 U/kg, 0.7 mg/kg) (B and E) or high doses (500 U/kg, 3.5 mg/kg) of heparin (C and F), 2/3-DS-H (C, D, F, and G), or PBS as control. Three days following the first injections (t = 0), intestinal protein leakage was induced by injection of either TNF-α (i.v., 0.1 mg/kg) (B–D) or IFN-γ (i.v., 0.2 mg/kg) and TNF-α (i.v., 0.1 mg/kg, 12 h after IFN-γ) (E–G). PBS was used as a control. All data represent assessment in a minimum of n = 4 mice (mean ± SD).