title: Platelet-Associated Matrix Metalloproteinases Regulate Thrombus Formation and Exert Local Collagenolytic Activity.
abstract: OBJECTIVE
  Platelets are increasingly implicated in processes beyond hemostasis and thrombosis, such as vascular remodeling. Members of the matrix metalloproteinase (MMP) family not only remodel the extracellular matrix but also modulate platelet function. Here, we made a systematic comparison of the roles of MMP family members in acute thrombus formation under flow conditions and assessed platelet-dependent collagenolytic activity over time.
  
  
  RESULTS
  Pharmacological inhibition of MMP-1 or MMP-2 (human) or deficiency in MMP-2 (mouse) suppressed collagen-dependent platelet activation and thrombus formation under flow, whereas MMP-9 inhibition/deficiency stimulated these processes. The absence of MMP-3 was without effect. Interestingly, MMP-14 inhibition led to the formation of larger thrombi, which occurred independently of its capacity to activate MMP-2. Platelet thrombi exerted local collagenolytic activity capable of cleaving immobilized dye-quenched collagen and fibrillar collagen fibers within hours, with loss of the majority of the platelet adhesive properties of collagen as a consequence. This collagenolytic activity was redundantly mediated by platelet-associated MMP-1, MMP-2, MMP-9, and MMP-14 but occurred independently of platelet α-granule release (Nbeal2(-/-) mice). The latter was in line with subcellular localization experiments, which indicated a granular distribution of MMP-1 and MMP-2 in platelets, distinct from α-granules. Whereas MMP-9 protein could not be detected inside platelets, activated platelets did bind plasma-derived MMP-9 to their plasma membrane. Overall, platelet MMP activity was predominantly membrane-associated and influenced by platelet activation status.
  
  
  CONCLUSIONS
  Platelet-associated MMP-1, MMP-2, MMP-9, and MMP-14 differentially modulate acute thrombus formation and at later time points limit thrombus formation by exerting collagenolytic activity.
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Tom G
authors.initials: TG
authors.lastname: Mastenbroek
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Marion A H
authors.initials: MA
authors.lastname: Feijge
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Romy M W
authors.initials: RM
authors.lastname: Kremers
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Marion T J
authors.initials: MT
authors.lastname: van den Bosch
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Frauke
authors.initials: F
authors.lastname: Swieringa
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Lies
authors.initials: L
authors.lastname: De Groef
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Lieve
authors.initials: L
authors.lastname: Moons
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Cavan
authors.initials: C
authors.lastname: Bennett
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Cedric
authors.initials: C
authors.lastname: Ghevaert
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Jason L
authors.initials: JL
authors.lastname: Johnson
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.).
authors.forename: Paola E J
authors.initials: PE
authors.lastname: van der Meijden
authors.affiliation: From the Department of Biochemistry (T.G.M., M.A.H.F., R.M.W.K., M.T.J.v.d.B., F.S., P.E.J.v.d.M., J.M.E.M.C.) and Synapse BV (R.M.W.K.), Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; School of Physiology and Pharmacology (M.T.J.v.d.B.) and School of Clinical Sciences (J.L.J.), University of Bristol, Bristol, United Kingdom; Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium (L.D.G., L.M.); Department of Haematology, University of Cambridge, Cambridge, United Kingdom (C.B., C.G.); and National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom (C.B., C.G.). judith.cosemans@maastrichtuniversity.nl.
authors.forename: Judith M E M
authors.initials: JM
authors.lastname: Cosemans
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology*; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism; D003094:Collagen / Q000378:metabolism*; D017364:Collagenases / Q000097:blood* / Q000172:deficiency / Q000235:genetics; D004195:Disease Models, Animal; D006801:Humans; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015539:Platelet Activation; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism; D059748:Proteolysis; D013927:Thrombosis / Q000097:blood / Q000201:enzymology* / Q000235:genetics; D013997:Time Factors
chemical_list: D001798:Blood Proteins; D061965:Matrix Metalloproteinase Inhibitors; C585423:Nbeal2 protein, mouse; D010980:Platelet Membrane Glycoproteins; C098341:platelet membrane glycoprotein VI; D003094:Collagen; D017364:Collagenases
keywords: blood platelets; collagen; matrix metalloproteinases; thrombosis; vascular remodeling