Histidine‐rich glycoprotein ameliorates endothelial barrier dysfunction through regulation of NF‐κB and MAPK signal pathway

Abstract

Background and Purpose Microvascular barrier breakdown is a hallmark of sepsis that is associated with sepsis‐induced multiorgan failure. Histidine‐rich glycoprotein (HRG) is a 75‐kDa plasma protein that was demonstrated to improve the survival of septic mice through regulation of cell shape, spontaneous ROS production in neutrophils, and adhesion of neutrophils to vascular endothelial cells. We investigated HRG's role in the LPS/TNF‐α‐induced barrier dysfunction of endothelial cells in vitro and in vivo and the possible mechanism, to clarify the definitive roles of HRG in sepsis. Experimental Approach EA.hy 926 endothelial cells were pretreated with HRG or human serum albumin before stimulation with LPS/TNF‐α. A variety of biochemical assays were applied to explore the underlying molecular mechanisms on how HRG protected the barrier function of vascular endothelium. Key Results Immunostaining results showed that HRG maintains the endothelial monolayer integrity by inhibiting cytoskeleton reorganization, losses of VE‐cadherin and β‐catenin, focal adhesion kinase degradation, and cell detachment induced by LPS/TNF‐α. HRG also inhibited the cytokine secretion from endothelial cells induced by LPS/TNF‐α, which was associated with reduced NF‐κB activation. Moreover, HRG effectively prevented the LPS/TNF‐α‐induced increase in capillary permeability in vitro and in vivo. Finally, Western blot results demonstrated that HRG prevented the phosphorylation of MAPK family and RhoA activation, which are involved mainly in the regulation of cytoskeleton reorganization and barrier permeability. Conclusions and Implications Taken together, our results demonstrate that HRG has protective effects on vascular barrier function in vitro and in vivo, which may be due to the inhibition of MAPK family and Rho activation.

P53 in the impaired lungs

“…The cellular cytoskeleton and glycocalyx regulate the morphology of the metabolically active endothelial cells [ [23] , [24] , [25] ]. The endothelium disruption may be due to the cytoskeletal reorganization and pathogen recognition by cellular receptors [ [26] , [27] , [28] , [29] ]. Lung endothelial hyperpermeability is the cause and consequence of inflammatory lung disease, including ALI or ARDS [ 30 , 31 ].…”

An Evaluation of the Activity of Histidine-Rich Glycoprotein on Differentiated Neutrophil-Like Cells from Human Cell Lines

“…Notably, the effective concentrations of HRG on human vascular endothelial cells were within the same range (Gao et al, 2019). HRG inhibited the PMA-induced upregulation of the expression of the activation epitope on CD11b on NLCs as observed in neutrophils (Wake et al, 2016).…”

“…Additionally, it repeatedly yielded a considerable number of NLCs. In previous studies (Gao et al, 2019;Wake et al, 2016), HRG was observed to induce the round shape of neutrophils, their smooth surface, and few microvilli. These neutrophils could easily pass through the microchannels and cause the lowest levels of spontaneous ROS production and less adhesion to the vascular endothelial cells and the artificial polystyrene wear.…”

“…HRG is a 75-kDa glycoprotein characterized by many histidine residues and GHHPH repeat sequences, synthesized in and secreted from the liver (Borza, Tatum, & Morgan, 1996;Koide, Foster, Yoshitake, & Davie, 1986;Poon, Patel, Davis, Parish, & Hulett, 2011). It exists in healthy human plasma at 60-100 µg/mL (approximately 1 µM) (Poon et al, 2011) and is reported to possess a variety of physiological activities, including the suppression of erythrocyte aggregation (Zhong et al, 2018), vascular endothelium protection (Gao et al, 2019;Gao et al, 2020), and regulation of blood cell adhesion (Wake et al, 2016). In the animal experiments, we reported that serum HRG levels in septic mice with cecal ligation and puncture (CLP) markedly dcerased while their survival rate increased after HRG supplementation, thus HRG was identified as an effective therapeutic strategy for sepsis (Wake et al, 2016).…”

Use of Tripterygium wilfordii Hook F for immune-mediated inflammatory diseases: progress and future prospects

“…When endothelial cells are damaged, there is an increase in capillary permeability and plasma exudation, which results in swelling of the joint (Middleton et al, 2004). Breakdown of the endothelial barrier function can also promote the adhesion of neutrophils to vascular endothelial cells, resulting in abnormal coagulation function, microvascular leakage, tissue hypoperfusion, and ultimately multiple organ failure (Opal and van der Poll, 2015;Gao et al, 2019). The permeability of endothelial cells increases with lipopolysaccharide and interferon-γ stimulation.…”