title: Deficiency in the serum-derived hyaluronan-associated protein-hyaluronan complex enhances airway hyperresponsiveness in a murine model of asthma.
abstract: BACKGROUND
  Serum-derived hyaluronan (HA)-associated proteins (SHAPs), the heavy chains of inter-α-trypsin inhibitor, covalently bind to HA to form the SHAP-HA complex. The SHAP-HA complex is involved in the pathophysiology of inflammatory diseases, including rheumatoid arthritis. We investigated whether this complex is also involved in airway allergy.
  
  
  METHODS
  SHAP-HA-deficient (bikunin knockout, KO) mice and wild-type (WT) mice were immunized twice by intraperitoneal injection of ovalbumin (OVA) and exposed to aerosol OVA for 30 min each day for 2 weeks. Twenty-four hours after the final OVA challenge, airway responsiveness to inhaled methacholine (MCh) was measured, and analysis of bronchoalveolar lavage fluid (BALF) and lung histological studies were done.
  
  
  RESULTS
  Compared to WT mice, KO mice showed higher airway hyperresponsiveness to inhaled MCh and higher late-phase responses to OVA whereas the early-phase responses were similar. Cell differentials of BALF showed an increased number of macrophages and neutrophils in KO mice. Furthermore, decreased concentrations of soluble tumor necrosis factor receptor-1 (sTNFR1) were found in BALF from KO mice whereas the levels of Th1 and Th2 cytokines were not different from WT mice. Immunochemical study of the lung tissues revealed stronger staining of sTNFR1 in KO than in WT mice.
  
  
  CONCLUSIONS
  Our results suggest that in this murine asthma model, the SHAP-HA complex has an inhibitory role in the development of airway hyperresponsiveness and allergic airway inflammation which may be attributed, at least in part, to negative feedback mechanisms exerted by sTNFR1, the shedding of which from the cell surface might also be promoted by the SHAP-HA complex.
authors.affiliation: Institute for Molecular Science of Medicine, Aichi Medical University School of Medicine, Yazako, Nagakute, Japan.
authors.forename: Long
authors.initials: L
authors.lastname: Zhu
authors.forename: Lisheng
authors.initials: L
authors.lastname: Zhuo
authors.forename: Koji
authors.initials: K
authors.lastname: Kimata
authors.forename: Etsuro
authors.initials: E
authors.lastname: Yamaguchi
authors.forename: Hideto
authors.initials: H
authors.lastname: Watanabe
authors.forename: Mark A
authors.initials: MA
authors.lastname: Aronica
authors.forename: Vincent C
authors.initials: VC
authors.lastname: Hascall
authors.forename: Kenji
authors.initials: K
authors.lastname: Baba
mesh_terms: D000818:Animals; D001249:Asthma / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000503:physiopathology*; D004195:Disease Models, Animal; D006820:Hyaluronic Acid / Q000097:blood / Q000737:chemistry / Q000172:deficiency*; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008168:Lung / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D012712:Serum Globulins / Q000737:chemistry / Q000172:deficiency
chemical_list: D007074:Immunoglobulin G; D012712:Serum Globulins; D007073:Immunoglobulin E; D006820:Hyaluronic Acid