Abstract:Renal involvement is a major medical concern in the diabetic population, and with the global epidemic of diabetes, diabetic nephropathy (DN) became the leading cause of end-stage renal failure in the Western world. Heparanase (the only known mammalian endoglycosidase that cleaves heparan sulfate) is essentially involved in DN pathogenesis. Nevertheless, the exact mode of heparanase action in sustaining the pathology of DN remains unclear. Here we describe a previously unrecognized combinatorial circuit of hepa… Show more
“…Heparanase is the only known mammalian endoglycosidase capable of cleaving HS (28)(29)(30). It is produced as a latent 65-kDa proenzyme that is processed and activated by cathepsin L, yielding an enzymatically active heterodimer composed of 8-and 50-kDa subunits (31).…”
Porcine reproductive and respiratory syndrome virus (PRRSV) continues to cause substantial economic losses to the pig industry worldwide. Heparan sulfate (HS) is used by PRRSV for initial attachment to target cells. However, the role of HS in the late phase of PRRSV infection and the mechanism of virus release from host cells remain largely unknown. In this study, we showed that PRRSV infection caused a decrease in HS expression and upregulated heparanase, the only known enzyme capable of degrading HS. We subsequently demonstrated that the NF-B signaling pathway and cathepsin L protease were involved in regulation of PRRSV infectioninduced heparanase. In addition, we found that ablation of heparanase expression using small interfering RNA duplexes increased cell surface expression of HS and suppressed PRRSV replication and release, whereas overexpression of heparanase reduced HS surface expression and enhanced PRRSV replication and release. These data suggest that PRRSV activates NF-B and cathepsin L to upregulate and process heparanase, and then the active heparanase cleaves HS, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) causes great economic losses each year to the pig industry worldwide. The molecular mechanism of PRRSV release from host cells largely remains a mystery. In this study, we demonstrate that PRRSV activates NF-B and cathepsin L to upregulate and process heparanase, and then the active heparanase is released to the extracellular space and exerts enzymatic activity to cleave heparan sulfate, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.KEYWORDS PRRSV, heparan sulfate, heparanase, viral release, porcine reproductive and respiratory syndrome virus P orcine reproductive and respiratory syndrome (PRRS) has become one of the most important diseases of intensive pig production worldwide since its emergence in the late 1980s (1, 2). This disease is characterized by respiratory disease, weight loss, and poor growth performance, as well as by late-term abortions (3). The causative agent, PRRS virus (PRRSV), is a small, enveloped, positive-sense, single-stranded RNA virus of the genus Arterivirus, in the family Arteriviridae within the order Nidovirales (4, 5). The PRRSV genome is approximately 15 kb in length and consists of at least 12 overlapping open reading frames (6, 7). Due to the genetic and antigenic differences, PRRSV can be divided into European genotype 1 and North American genotype 2, with Lelystad and VR-2332 as prototypical strains, respectively, which share about 60% nucleotide sequence identity (8). In 2006, highly pathogenic PRRSV (HP-PRRSV)
“…Heparanase is the only known mammalian endoglycosidase capable of cleaving HS (28)(29)(30). It is produced as a latent 65-kDa proenzyme that is processed and activated by cathepsin L, yielding an enzymatically active heterodimer composed of 8-and 50-kDa subunits (31).…”
Porcine reproductive and respiratory syndrome virus (PRRSV) continues to cause substantial economic losses to the pig industry worldwide. Heparan sulfate (HS) is used by PRRSV for initial attachment to target cells. However, the role of HS in the late phase of PRRSV infection and the mechanism of virus release from host cells remain largely unknown. In this study, we showed that PRRSV infection caused a decrease in HS expression and upregulated heparanase, the only known enzyme capable of degrading HS. We subsequently demonstrated that the NF-B signaling pathway and cathepsin L protease were involved in regulation of PRRSV infectioninduced heparanase. In addition, we found that ablation of heparanase expression using small interfering RNA duplexes increased cell surface expression of HS and suppressed PRRSV replication and release, whereas overexpression of heparanase reduced HS surface expression and enhanced PRRSV replication and release. These data suggest that PRRSV activates NF-B and cathepsin L to upregulate and process heparanase, and then the active heparanase cleaves HS, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) causes great economic losses each year to the pig industry worldwide. The molecular mechanism of PRRSV release from host cells largely remains a mystery. In this study, we demonstrate that PRRSV activates NF-B and cathepsin L to upregulate and process heparanase, and then the active heparanase is released to the extracellular space and exerts enzymatic activity to cleave heparan sulfate, resulting in viral release. Our findings provide new insight into the molecular mechanism of PRRSV egress from host cells, which might help us to further understand PRRSV pathogenesis.KEYWORDS PRRSV, heparan sulfate, heparanase, viral release, porcine reproductive and respiratory syndrome virus P orcine reproductive and respiratory syndrome (PRRS) has become one of the most important diseases of intensive pig production worldwide since its emergence in the late 1980s (1, 2). This disease is characterized by respiratory disease, weight loss, and poor growth performance, as well as by late-term abortions (3). The causative agent, PRRS virus (PRRSV), is a small, enveloped, positive-sense, single-stranded RNA virus of the genus Arterivirus, in the family Arteriviridae within the order Nidovirales (4, 5). The PRRSV genome is approximately 15 kb in length and consists of at least 12 overlapping open reading frames (6, 7). Due to the genetic and antigenic differences, PRRSV can be divided into European genotype 1 and North American genotype 2, with Lelystad and VR-2332 as prototypical strains, respectively, which share about 60% nucleotide sequence identity (8). In 2006, highly pathogenic PRRSV (HP-PRRSV)
“…30 Indeed, HS has been shown to be involved in various inflammatory models, including inflammatory bowel disease 29 and diabetic nephropathy. 16 One way in which HS could be directly involved in nociception is through the sensitization of macrophages resulting in increased levels of tumor necrosis factor alpha and interleukin 1 (IL-1), both key inflammatory mediators in nociception (Fig. 1A, third panel).…”
Section: Extracellular Matrix and General Nociceptionmentioning
“…Goldberg et al [38] have also recently shown that HPSE fuels chronic inflammation in diabetic nephropathy: inactive HPSE produced by glomeruli and activated by cathepsin- l released by tubular cells sustains a persistent activation of kidney-damaging macrophages, thus creating chronic inflammatory conditions and fostering macrophage-mediated renal injury (Figure 4). Figure 4Involvement of HPSE in renal fibrosis.…”
Tubulo-interstitial fibrosis has been recognized as the hallmark of progression of chronic kidney disease, but, despite intensive research studies, there are currently no biomarkers or effective treatments for this condition. In this context, a promising candidate could be heparanase-1 (HPSE), an endoglycosidase that cleaves heparan sulfate chains and thus takes part in extracellular matrix remodeling. As largely described, it has a central role in the pathogenesis of cancer and inflammation, and it participates in the complex biological machinery involved in the onset of different renal proteinuric diseases (e.g., diabetic nephropathy, glomerulonephritis). Additionally, HPSE may significantly influence the progression of chronic kidney damage trough its major role in the biological pathway of renal fibrogenesis. Here, we briefly summarize data supporting the role of HPSE in renal damage, focusing on recent evidences that demonstrate the capability of this enzyme to modulate the signaling of pro-fibrotic factors such as FGF-2 and TGF-ÎČ and consequently to control the epithelial-mesenchymal transition in renal tubular cells. We also emphasize the need of the research community to undertake studies and clinical trials to assess the potential clinical employment of this enzyme as diagnostic and prognostic tool and/or its role as therapeutic target for new pharmacological interventions.
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