TABLE 1.

The function, shedding enzyme and protection strategies of glycocalyx in cerebrovascular.

(A) Functions	Regulation of vascular permeability	Mechanical barrier and charge barrier	Deen et al., 2001; Kutuzov et al., 2018; Zhu et al., 2018
	Regulation of vascular tone	Inducing and transmitting the shear stress change signal to the endothelial cells to synthesize and release nitric oxide	Ebong et al., 2014; Yen et al., 2015; Bartosch et al., 2017
	Attenuation of leukocyte adhesion	Reducing leukocyte contact with ICAM-1,ICAM-2, and VCAM-1	Van den Berg et al., 2006; Kim et al., 2013
	Attenuation of platelet adhesion	Reducing platelet contact with PECAM-1	Bell et al., 2017; Lupu et al., 2020
(B) Major shedding enzyme	MMPs	Cleaving core protein backbone of glycocalyx, directly	Endo et al., 2003; Song et al., 2015; Reine et al., 2019; Ali et al., 2019
	HPSE	Cutting HS	Shteper et al., 2003; Baraz et al., 2006; Qu et al., 2016; Zheng et al., 2016
	HAase	Cutting HA	Nieuwdorp et al., 2007; Becker et al., 2015
(C) Protection strategies of glycocalyx	Glucocorticoid	Stabilizing mast cells	Cui et al., 2015; Yu et al., 2019
	Antithrombin agents	Stabilizing glycocalyx structure by combining with it	Chappell et al., 2009a,b
	Abumin	Similar to that of antithrombin	Becker et al., 2015; Aldecoa et al., 2020
	Etanercept	TNF-α inhibitor	Nieuwdorp et al., 2009
	Sulodexide	Inhibiting HPSE and MMPs activities	Mannello and Raffetto, 2011; van Haare et al., 2017
	Doxycycline and batimastat	Inhibitors of MMPs	Lipowsky et al., 2011; Lipowsky and Lescanic, 2013
	Sevoflurane	Reduce MMPs production	Annecke et al., 2010; Fang et al., 2021

ICAM, intercellular adhesion molecules; VCAM, vascular cell adhesion molecule; PECAM, platelet/endothelial cell adhesion molecule; HPSE, heparinase; HAase, hyaluronidase; MMPs, matrix metalloproteinases; TIMPs tissue inhibitor of matrix metalloproteinases; HDAC, histone deacetylase; HA, hyaluronic acid; HS, heparan sulfate.