Table 1.
Overview on mechanistic approaches to prevent or counteract damage of the endothelial glycocalyx.
| First Author | Year | Model | Methods | Protection/Rescue strategy |
|---|---|---|---|---|
| X. Du [6] | 2021 | - cell culture | - immunofluorescence - FITC-dextran permeability assay |
Anisodamine Hydrobromide prevents LPS-induced loss of HS and reduces cell barrier permeability. |
| A. Lukasz [19] | 2019 | - C57BL/6J mice - cell culture |
- IVM (SDF, back skin) - Miles assay - AFM - immunofluorescence - heparanase activity |
Angpt-2 leads to PBR increase in vivo and causes heparanase-dependent eGC decline in vitro. NAH reduces Angpt-2 induced leakage. Angpt-1, L1-10 (Angpt-2 inhibition) and NAH prevent Angpt-2 induced eGC decline. |
| A.A. Constantinescu [24] | 2011 | - male C57BL/6J mice - transgenic ApoE3-Leiden mice |
- IVM (M. cremaster) | High-fat cholesterol-enriched diets lead to subendothelial lipid deposits and decrease eGC in these areas. |
| H. Vink [26] | 2000 | - male golden hamster | - IVM (M. cremaster) | Bolus of oxidized LDL leads to transient reduction of eGC and increased platelet adhesion. Super-oxide dismutase + catalase treatment prevents eGC reduction and platelet adhesion. |
| E.P. Schmidt [31] | 2012 | - male C57BL/6 mice - Hpse−/− mice - Tnfrsf1atm1Imx mice - cell culture |
- IVM (FITC-dextran 150kDa, lung, M. cremaster) - HS degradation activity - Western blot |
In wild type mice LPS-induced eGC loss is heparanase-dependent and can be prevented with NAH or heparin administration. Neutrophil adhesion is attenuated and survival improved in Hpse−/− mice. TNFR1-knockout and Hpse-/- mice show no loss of eGC upon treatment with LPS. |
| X. Yang [32] | 2018 | - ADAM15-/- mice - wild-type mice - human lungs ex vivo |
- IVM (FITC-albumin, -dextran 150kDa, cremaster, mesentery) - electron microscopy - ELISA |
LPS-induced eGC damage and vascular leakage is significantly reduced in ADAM15-/- mice. In CLP ADAM15-/- mice show less increase of soluble CD44, mechanistically suggesting ADAM15-dependent shedding of CD44. |
| C.B.S. Henry [33] | 2000 | - male Syrian golden hamsters | - IVM (FITC-dextran 40, 70, 580, or 2,000, FITC-albumin, M. cremaster) | Fucoidan leads to reduction of TNFα-induced leukocyte adherence but does not change FITC penetration to the eGC. |
| R. Ramnath [34] | 2014 | - cell culture | - immunofluorescence - Alcian blue dye binding assay - TaqMan low-density array |
TNFα induces shedding of HS and SDC-4 which can be counteracted by pretreatment with batimastat (MMP inhibitor) or MMP9 siRNA. |
| Y. Zeng [35] | 2014 | - cell culture | - immunofluorescence - DMMB assay |
S1P prevents loss of CS, HS and SDC-1 coverage in FBS and BSA free medium and reduces MMP activity (which can be counteracted by S1P inhibitor W146). Specific inhibition of MMP-9 and MMP13 prevents loss of CS. |
| A. Wiesinger [38] | 2013 | - Lewis-Brown Norway rats - male C57BL/6 mice - cell culture |
- AFM, (cells, aorta ex vivo) - electron microscopy |
TNFα, LPS, thrombin or heparinase I induce eGC decline. Heparin preserves eGC upon treatment with heparinase I. |
| D. Chappell [40] | 2009 | - isolated guinea pig hearts | - ELISA - electron microscopy |
Hydrocortisone and antithrombin III prevent TNFα-induced eGC decline. Both prevent increase of shed SDC-1 and HS (for HS stronger effect of hydrocortisone). |
| K. Stahl [55] | 2020 | - cell culture | - immunofluorescence | COVID-19 serum induces eGC damage in vitro but not in case of transgenic overexpression of heparanase 2. |
| N. Cui [56] | 2015 | - male Sprague-Dawley rats | - gelatin zymogram -immunohistochemistry - ELISA |
Dexamethasone and doxycycline both significantly suppress LPS-induced MMP-2 and -9 expression and both partially inhibit decline of SDC-1. |
| M. Nieuwdorp [57] | 2009 | - human male volunteers | - IVM (orthogonal polarization spectroscopy imaging, sublingual) - ELISA |
Etanercept reduces LPS-induced decline in eGC thickness and attenuates increase in hyaluronan. |
| C.C. Drost [59] | 2019 | - cell culture | - AFM - immunofluorescence |
Sepsis serum induces eGC decline which can be counteracted with administration of NAH, VT (Tie2 activation), or L1-10 (Angpt-2 inhibition). VT restores eGC damage in case of delayed administration and reduces heparanase activity. Delayed VT and Angpt-1 administration attenuate heparinase I induced eGC damage. |
| S. Chen [60] | 2017 | - male C57BL/6 mice | - immunohistochemistry - ELISA - Western blot |
NAH attenuates CLP-induced eGC damage, inhibits leukocyte infiltration and reduces heparanase serum levels, heparanase expression and loss of SDC-1, potentially via MMP-9 and uPA reduction. NAH further suppresses production of inflammatory cytokines. |
| X. Huang [61] | 2019 | - male Sprague-Dawley rats | - ELISA - heparanase activity assay - immunofluorescence - wet/dry ratio - histologic examination |
UFH and NAH similarly prevent LPS-induced increase of HS, SDC-1 and heparanase activity. Both attenuate lung tissue injury and reduce production of inflammatory cytokines. |
| S. Yini [63] | 2015 | - adult beagle dogs | - ELISA | UFH significantly prevents decline of SDC-1 and HS upon infusion of E. coli compared to basic treatment (ceftriaxone + fluid resuscitation). Survival between both groups was not significantly different. |
| L. Wang [65] | 2016 | - C57BL/6 mice - cell culture |
- ELISA - heparanase activity assay - immunofluorescence - Evans blue dye extravasation technique |
Ulinastatin prevents LPS-induced HS increase, reduces heparanase activity and expression and attenuates vascular permeability. |
| V. Masola [69] | 2012 | - cell culture | - heparanase activity assay - mRNA expression analysis |
Sulodexide reduces FGF-2-mediated heparanase overexpression and SDC-1 downregulation. |
| J.W. Song [70] | 2017 | - C57/BL6 mice - cell culture |
- distribution of FITC-dextran 40, 70, 500kDa - Evans blue dye extravasation technique - immunofluorescence - AFM |
Sulodexide restores FIP- (feces-induced peritonitis) or LPS-induced loss of eGC volume, reduces vascular permeability and improves survival. |
| T. Li [71] | 2017 | - male Sprague-Dawley rats | - electron microscopy - immunohistochemistry - immunofluorescence |
Sulodexide leads to recovery of eGC and normal eNOS levels, reduces CD31 and ICAM-1 and decreases inflammatory cell infiltration after carotid artery balloon-injury. |
| D. Chappell [75] | 2007 | - isolated guinea pig hearts | - electron microscopy - ELISA |
Hydrocortisone preserves eGC with less tissue edema and reduces HS, hyaluronan and SDC-1 shedding in an ischemia-reperfusion model. |
| S.L. Gao [76] | 2015 | - male Sprague-Dawley rats | - electron microscopy - ELISA |
Hydrocortisone stabilizes eGC and reduces HS and SDC-1 levels and improves intestinal perfusion in severe acute pancreatitis. |
| T. Iba [79] | 2021 | - rats (Wistar) | - IVM (leukocyte adhesion, SDF) - ELISA |
AT-γ ameliorates LPS-induced impairment of microcirculation with decrease of PBR and reduction of SDC-1 and hyaluronan levels. |
| S. Han [87] | 2016 | - C57BL/6J mice - Ang1flox/flox mice - Ang2flox/flox mice - Tie2flox/flox mice - cell culture |
- IVM (FITC-dextran 40kDa) - immunofluorescence - Evans blue dye extravasation technique |
Administration of ABTAA (Angpt-2 binding and Tie2 activating antibody) improves survival in LPS, CLP and S. aureus sepsis model, reduces leakage and production of inflammatory cytokines, prevents shedding of HS and perlecan and reduces heparanase density in lung and kidney tissue. Thickness of the eGC improves upon ABTAA treatment with reduced leukocyte adhesion and improved vascular perfusion. |
| A.H.J. Salmon [88] | 2009 | - adult frog - rats (Wistar) - cell culture |
- perfusion (Landis–Michel technique, oncopressive permeability technique) - electron microscopy - Alcian Blue assay |
Angpt-1 restores direct contact of eGC to plasmalemma after separation upon pronase perfusion. Angpt-1 decreases water permeability of the endothelium and increases depth of eGC as well as GAG turnover in healthy vessels. |
Abbreviations: ADAM (a disintegrin and metalloproteinase), AFM (atomic force microscopy), Angpt-1 (angiopoietin-1), Angpt-2 (angiopoietin-2), AT-γ (newly developed recombinant non-fucosylated antithrombin), BSA (bovine serum albumin), CLP (cecal ligation and puncture), CS (chondroitin sulfate), E. coli (Escherichia coli), eGC (endothelial glycocalyx), ELISA (enzyme-linked immunosorbent assay), eNOS (endothelial nitric oxide synthase), FBS (fetal bovine serum), FGF-2 (fibroblastic growth factor 2), FIP (feces-induced peritonitis), FITC (fluorescein isothiocyanate), GAG (glycosaminoglycan), HS (heparan sulfate), Hpse (heparanase), ICAM-1 (intercellular adhesion molecule 1), IF (immunofluorescence), IVM (intravital microscopy), LDL (low-density lipoprotein), LPS (lipopolysaccharide), MMP (matrix metalloproteinase), NAH (N-desulfated/re-N-acetylated heparin), PBR (perfused boundary region), S. aureus (Staphylococcus aureus), SDC (syndecan), SDF (side-stream darkfield), siRNA (short interfering ribonucleic acid), S1P (sphingosine-1-phosphate), TNFα (tumor necrosis factor α), UFH (unfractionated heparin), uPA (urokinase-type plasminogen activator), VT (Vasculotide™)