High levels of serum hyaluronan is an early predictor of dengue warning signs and perturbs vascular integrity

Abstract

Background: A main pathological feature of severe dengue virus infection is endothelial hyper-permeability. The dengue virus nonstructural protein 1 (NS1) has been implicated in the vascular leakage that characterizes severe dengue virus infection, however, the molecular mechanisms involved are not known. Methods: A cohort of 250 dengue patients has been followed from the onset of symptoms to the recovery phase. Serum hyaluronan levels and several other clinical parameters were recorded. The effect of NS1 treatment of cultured fibroblasts and endothelial cells on the expressions of hyaluronan synthetic and catabolic enzymes and the hyaluronan receptor CD44, were determined, as have the effects on the formation of hyaluronan-rich matrices and endothelial permeability. Findings: Elevated serum hyaluronan levels (≥70 ng/ml) during early infection was found to be an independent predictor for occurrence of warning signs, and thus severe dengue fever. High circulating levels of the viral protein NS1, indicative of disease severity, correlated with high concentrations of serum hyaluronan. NS1 exposure decreased the expression of CD44 in differentiating endothelial cells impairing the integrity of vessel-like structures, and promoted the synthesis of hyaluronan in dermal fibroblasts and endothelial cells in synergy with dengue-induced pro-inflammatory mediators. Deposited hyaluronan-rich matrices around cells cultured in vitro recruited CD44-expressing macrophage-like cells, suggesting a mechanism for enhancement of inflammation. In cultured endothelial cells, perturbed hyaluronan-CD44 interactions enhanced endothelial permeability through modulation of VE-cadherin and cytoskeleton reorganization , and exacerbated the NS1-induced disruption of endothelial integrity. Interpretation: Pharmacological targeting of hyaluronan biosynthesis and/or its CD44-mediated signaling may limit the life-threatening vascular leakiness during moderate-to-severe dengue virus infection.

Dengue Immunopathogenesis: A Crosstalk between Host and Viral Factors Leading to Disease: PART II - DENV Infection, Adaptive Immune Responses, and NS1 Pathogenesis

“…Additional biological markers such as serum lipids [157,158], prostaglandins, leukotrienes and thromboxane [151,159], free radical compounds such as reactive oxygen and nitrogen oxide species [160,161], MPPs [162][163][164], and several components of the endothelium in the microvasculature such as the vascular cell adhesion molecule 1 (VCAM-1), Angiopoietin-1 and -2 (Ang-1, −2), endothelial-1, [5,163,[165][166][167] or carbohydrates including glycosaminoglycans (GAGs) and proteoglycans (e.g. HSPG) [168][169][170][171] have been suggested to play important roles in the pathogenesis of different viral infections, including DENV. Changes in the plasma or urine levels of these molecules have been shown to act as potential predictors for clinical outcome between patients with different stages of DHF disease severity and predictors of disease severity in animal models in vivo [168,[170][171][172][173][174].…”

“…HSPG) [168][169][170][171] have been suggested to play important roles in the pathogenesis of different viral infections, including DENV. Changes in the plasma or urine levels of these molecules have been shown to act as potential predictors for clinical outcome between patients with different stages of DHF disease severity and predictors of disease severity in animal models in vivo [168,[170][171][172][173][174].…”

“…This bioavailability feature of NS1 launched it as a diagnostic marker for acute primary and secondary DENV infections and potentially other flavivirus diseases [54,[223][224][225]. NS1 antigenemia can reach as high as 50 μg/mL during the acute phase of dengue illness correlating with the development of DHF and sometimes fatality cases [12,14,54,170,223,[226][227][228]. These observations suggest that circulating levels of NS1 in the bloodstream of patients during the clinical phase of the disease may contribute to DENV pathogenesis.…”

“…On the vascular endothelium, the EGL constitutes a network of GAGs such as heparan sulfate, chondroitin sulfate, and hyaluronic acid, and proteoglycans (e.g., syndecans, glypicans, and perlecan) that contributes to maintain the homeostasis of the endothelial barrier function [280]. Degradation of the EGL and the detection of its degradation products in cell supernatants and human plasma have been linked to virus pathogenesis and disease severity in several viral hemorrhagic fever diseases [281], including dengue, where increased levels of heparan sulfate, hyaluronic acid, sialic acid, and syndecan-1 have been found to correlate with severe dengue disease in humans and lethality in animal models [3,[168][169][170]172].…”

Dengue virus non structural protein 1 disrupts the TGF-β/Smad signaling by utilizing E3 ligase Smurf2

“…As TGF-β signaling is involved in majority of cellular processes, hence it could be a potential target for DENV. Many researchers have reported increased levels of TGF-β cytokine in DENV infection 15,16 . So far, the mechanism of TGF-β signaling during DENV infection is not well understood.…”