Platelet-Derived Hyaluronidase 2 Cleaves Hyaluronan into Fragments that Trigger Monocyte-Mediated Production of Proinflammatory Cytokines
AMERICAN JOURNAL OF PATHOLOGY
Authors: de la Motte, Carol; Nigro, Julie; Vasanji, Amit; Rho, Hyunjin; Kessler, Sean; Bandyopadhyay, Sudip; Danese, Silvio; Fiocchi, Claudio; Stern, Robert
Abstract
Hyaluronan (RA) occurs in the body as a large, hydrating, space-filling, carbohydrate polymer in the extracellular matrix; it has both anti-angiogenic and immunosuppressive properties. Cleavage of HA results in the generation of variably sized fragments that stimulate multiple angiogenic and inflammatory responses in a size-specific manner. in this study, we report that platelets, as well as their megakaryocyte precursors, are unusual among somatic cells in that they contain only hyaluronidase 2 (HYAL2) but not HYAL1. Platelet HYAL2 is sufficient to cleave HA into fragments that are specific for inflammatory and angiogenic signaling; this process occurs in the absence of HYAL1, which is necessary in all other tissues to perform further HA degradation. Platelets can bind to RA, some of which derives from the stressed microvessel endothelial cell surface. Platelet-derived HYAL2 cleaves RA into fragments that stimulate mononuclear leukocytes in the immediate microenvironment to produce proinflammatory cytokines, including interleukin-6 and interleukin-8. Platelets, thus, are not only involved in hemostasis, the earliest step in wound healing, but are also important in the signaling of subsequent inflammatory and angiogenic steps. We hypothesize that aberrations in these sequential steps can promote chronic inflammation, as found in inflammatory bowel disease. The platelet may thus provide an interface between acute and chronic inflammation, wound healing, and their subsequent fibrotic responses. (Am J Pathol 2009, 174:2254-2264; DOI: 10.2353/ajpath.2009.080831)
Hyaluronidase splice variants are associated with histology and outcome in adenocarcinoma and squamous cell carcinoma of the lung
HUMAN PATHOLOGY
Authors: de Sa, Vanessa Karen; Olivieri, Eloisa; Parra, Edwin Roger; Ab'Saber, Alexandre Muxfeldt; Takagaki, Teresa; Soares, Fernando Augusto; Carraro, Dirce; Carvalho, Lina; Capelozzi, Vera Luiza
Abstract
Heterogeneity of hyaluronidase (HYAL) expression has been identified in tumors and shows promise as an indicator of disease progression. The expression profile of alternatively spliced forms of HYAL was evaluated in tumors and normal lung tissue from 69 resected tumors of patients with adenocarcinomas and squamous cell carcinomas. HYAL1-wild-type (wt) and variants 1 to 5, HYAL2-wt, and HYAL3-wt, and variants 1 to 3 were identified by polymerase chain reaction and direct sequencing. Different proportions of the 3 HYAL-wt and variants were expressed in tumor and normal lung tissues. HYAL1-wt was associated with a poorer prognosis and HYAL3-vl with a better prognosis. HYAL splice variants are associated with histology and outcome, suggesting that strategies aimed at modulating their levels may be effective for lung cancer treatment. (C) 2012 Elsevier Inc. All rights reserved.