Deficiency in mouse hyaluronidase 2: a new mechanism of chronic thrombotic microangiopathy.
Hyaluronan is a major component of the extracellular matrix and glycocalyx. Its main somatic degrading enzymes are hyaluronidases 1 and 2, neither of which is active in the bloodstream. We generated hyaluronidase 2-deficient mice. These animals suffer from chronic, mild anemia and thrombocytopenia, in parallel with a 10-fold increase in plasma hyaluronan concentration. In this study we explored the mechanism of these hematologic anomalies. The decreased erythrocyte and platelet counts were attributed to peripheral consumption. The erythrocyte half-life was reduced from 25 to 8 days without signs of premature aging. Hyaluronidase 2-deficient platelets were functional. Major intrinsic defects in erythrocyte membrane or stability, as well as detrimental effects of high hyaluronan levels on erythrocytes, were ruled out in vitro. Normal erythrocytes transfused into hyaluronidase 2-deficient mice were quickly destroyed but neither splenectomy nor anti-C5 administration prevented chronic hemolysis. Schistocytes were present in blood smears from hyaluronidase 2-deficient mice at a level of 1% to 6%, while virtually absent in control mice. Hyaluronidase 2-deficient mice had increased markers of endothelial damage and microvascular fibrin deposition, without renal failure, accumulation of ultra-large multimers of von Willebrand factor, deficiency of A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motifs, member 13 (ADAMTS13), or hypertension. There was no sign of structural damage in hepatic or splenic sinusoids, or in any other microvessels. We conclude that hyaluronidase 2 deficiency induces chronic thrombotic microangiopathy with hemolytic anemia in mice. The link between this uncommon condition and hyaluronidase 2 remains to be explored in humans.
Molecular Physiology Research Unit, NARILIS, University of Namur, Belgium.
Cécile
C
Onclinx
Molecular Physiology Research Unit, NARILIS, University of Namur, Belgium.
Sophie
S
Dogne
Molecular Physiology Research Unit, NARILIS, University of Namur, Belgium.
Laurence
L
Jadin
Laboratoire d'Immunobiologie, Institut de Biologie et de Médecine Moléculaire, Université Libre de Bruxelles, Belgium.
Fabienne
F
Andris
Interfacultary Research Centre of Biomaterials (CEIB), University of Liège, Belgium.
Christian
C
Grandfils
Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA), Cardiovascular Sciences, University of Liège, Quartier Hôpital, Avenue Hippocrate, Belgium.
François
F
Jouret
Hematology Laboratory, Namur Thrombosis and Hemostasis Center, CHU Dinant Godinne UCL Namur, Belgium.
François
F
Mullier
Molecular Physiology Research Unit, NARILIS, University of Namur, Belgium bruno.flamion@unamur.be.
Bruno
B
Flamion
D000071120:ADAMTS13 Protein; D000748:Anemia, Macrocytic / Q000097:blood / Q000235:genetics; D000818:Animals; D001809:Blood Viscosity / Q000235:genetics; D016026:Bone Marrow Transplantation; D002470:Cell Survival / Q000235:genetics; D016922:Cellular Senescence / Q000235:genetics; D004195:Disease Models, Animal; D004909:Erythrocyte Indices; D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism; D004913:Erythrocytes, Abnormal / Q000378:metabolism; D058851:GPI-Linked Proteins / Q000172:deficiency; D006820:Hyaluronic Acid / Q000097:blood; D006821:Hyaluronoglucosaminidase / Q000172:deficiency*; D007668:Kidney / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008666:Metalloendopeptidases / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D013921:Thrombocytopenia / Q000097:blood / Q000235:genetics; D057049:Thrombotic Microangiopathies / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy
D058851:GPI-Linked Proteins; D006820:Hyaluronic Acid; C469221:Hyal2 protein, mouse; D006821:Hyaluronoglucosaminidase; C502939:ADAMTS13 protein, mouse; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein