J. Evan Sadler, M.D., Ph.D.

Evan Sadler
  • Professor
    • Department of Medicine
      • Hematology Division
    • Department of Biochemistry & Molecular Biophysics
  • Clinical interests
    • Hemostasis
  • Research interests
    • Blood coagulation
    • Serine proteases
    • von Willebrand disease
    • Enteropeptidase

Research

My laboratory studies the pathophysiology of hemorrhage and thrombosis, focusing on the mechanisms that promote and inhibit platelet adhesion. Von Willebrand factor (VWF) is a multimeric protein that mediates platelet adhesion to sites of vascular injury and stabilizes blood coagulation factor VIII; these interactions are essential for hemostasis. Von Willebrand disease (VWD) is caused by deficiency of VWF, and is the most common inherited bleeding disorder. Specific domains of VWF interact with platelet receptor proteins, and binding is regulated allosterically. A single VWF multimer can be enormous, up to 100 micrometers in length, and the largest multimers are the most hemostatically active. We are investigating the mechanism of VWF multimer assembly and the regulation of VWF binding to its receptors on platelets. VWF assembly into large multimers is required to prevent bleeding and, conversely, the proteolytic cleavage of VWF multimers is required to prevent thrombosis. We recently cloned a metalloprotease with a complex multidomain structure, ADAMTS13, which participates in the feedback inhibition of VWF function by cleaving a Tyr-Met bond in the center of the VWF subunit. Interestingly, VWF cleavage by ADAMTS13 is regulated by tensile stress, so that VWF only becomes susceptible when it is stretched at the site of a growing platelet thrombus. We are determining how various domains of ADAMTS13 cooperate to recognize and cleave VWF. Congenital or acquired deficiency of ADAMTS13 causes life-threatening microvascular thrombosis (thrombotic thrombocytopenic purpura), and we are investigating the clinical utility of ADAMTS13 assays in the diagnosis and treatment of thrombotic thrombocyotpenic purpura.

vWF assembly

Model for the assembly, tubular packing, and secretion of VWF multimers

(A and B) In the ER, proVWF subunits dimerize through disulfide bonds between C-terminal CK domains (small gray spheres). The propeptide consists of domains D1 ("1," yellow) and D2 ("2," orange) and is linked to D'D3 of the mature subunit ("3," blue) by a furin cleavage site (green). Two potential orientations of the propeptide are distinguished by whether homodimer contacts involve domain D1 (A) or D2 (B). In either case, pH-dependent interactions bring two D′D3 domains together and facilitate intersubunit disulfide bond formation.
(C) The propeptide (yellow) and dimeric D′D3 domains (blue) pack into a helix surrounded by the C-terminal remainder of the VWF subunits (gray).
(D) Secretion exposes the tubules to blood at pH 7.4, which destabilizes the contacts between propeptide and D′D3 domains and allows extension of the multimer.

From: Huang RH, Wang Y, Roth R, Yu X, Purvis AR, Heuser JE, Egelman EH, Sadler JE
Assembly of Weibel-Palade body-like tubules from N-terminal domains of von Willebrand factor.
Proc Natl Acad Sci U S A 2008 Jan 15;105(2):482-7

Biographical Sketch

Education

1969-1973 A.B. in Chemistry (summa cum laude), Princeton University, Princeton, NJ
1973-1979 Duke University Medical Center, Durham, NC
1978 - Ph.D. in Biochemistry, Robert L. Hill, advisor
1979 - M.D.

Post-graduate Training

1979-1981 Duke University Medical Center, Durham, NC
1979 - Research Associate, Department of Biochemistry
1979-1980 - Intern in Medicine
1980-1981 - Junior Assistant Resident in Medicine
1981-1984 University of Washington, Seattle, WA
1981-1984 - Fellow in Hematology, Department of Medicine
1982-1984 - Associate, Department of Pharmacology
1982-1984 - Associate, Howard Hughes Medical Institute at Seattle

Academic Positions

1984-1996 Associate Investigator, Howard Hughes Medical Institute at St. Louis
1984-1989 Assistant Professor of Medicine, Washington University School of Medicine, St. Louis, MO
1989-1993 Associate Professor of Medicine, Washington University School of Medicine, St. Louis, MO
1985-1993 Assistant Professor of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
1993-present Professor of Medicine, Hematology Division, Washington University School of Medicine, St. Louis, MO
1993-present Professor of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
1996-2008 Investigator, Howard Hughes Medical Institute at St. Louis
2009-present Chief, Division of Hematology, Department of Medicine, Washington University School of Medicine, St. Louis, MO

University & Hospital Appointments

1990-1991 Molecular Biology Steering Committee, Division of Biology and Biomedical Sciences
1989-1991 Metabolic Regulation Preliminary Examination Committee, Division of Biology and Biomedical Sciences
1991 - Chairman
1989-1993 MA/MD Program Committee, Division of Biology and Biomedical Sciences
1991 Ad Hoc Committee to Examine the Biomedical Research Computing Facility Services
1992-1999 Molecular Cell Biology Steering Committee, Division of Biology and Biomedical Sciences
1992-1995 Transfusion Review Committee, The Jewish Hospital of St. Louis
1996-present Transfusion Review Committee, Barnes-Jewish Hospital
2003-2006 Academic Freedom and Tenure Hearing Committee
2007-2010 Co-director, Hematology-Oncology Fellowship Program

Board Certification

1982 Diplomate, American Board of Internal Medicine

Honors & Awards

1973 Everett S. Wallis Prize in Organic Chemistry, Princeton University
1973 Robert Thornton McCay Prize (Physical Chemistry), Princeton University
1973 Phi Beta Kappa
1976 Alpha Omega Alpha
1988 American Society for Clinical Investigation
1993 Association of American Physicians
1995 Investigator Recognition Award, Seventh Biennial Awards for Contributions to Hemostasis, ISTH, Jerusalem, Israel
1997 Investigator Recognition Award, Eighth Biennial Awards for Contributions to Hemostasis, ISTH, Florence, Italy
1998 William Dameshek Prize, American Society of Hematology
1998 Fellow, American Association for the Advancement of Science, Medical Sciences (N)
2001 Distinguished Career Award, Tenth Biennial Awards for Contributions to Hemostasis, ISTH, Paris, France
2001 Fellow, American Heart Association

Editorial Responsibilities

1988-1992 Editorial Board, Blood
1989-1993 Editorial Board, The Journal of Biological Chemistry
1993-2002 Associate Editor, Blood
1993-present Editorial Advisory Board, Biochemistry
1998-2010 Board of Consulting Editors, Journal of Clinical Investigation
1999-2002 Advisory Board, Thrombosis and Haemostasis
2003-2006 Advisory Board, Journal of Thrombosis and Haemostasis
2003-2007 Editorial Advisory Board, ASBMB Today
2005-2007 Faculty of 1000 Medicine Project
2006-2007 Editorial Board, Arteriosclerosis Thrombosis and Vascular Biology
2007-2013 Editorial Board, Journal of Thrombosis and Haemostasis
2008-present Editorial Board, Blood
2012-present Board of Consulting Editors, Journal of Clinical Investigation

Professional Societies & Organizations

1978-present Sigma Xi
1981-present American Association for the Advancement of Science
1985-present American Society for Biochemistry and Molecular Biology
1985-present American Society of Hematology
1989-1992 - Scientific Subcommittee on Hemostasis
1994-1996 - Scientific Subcommittee on Hemostasis
1994 - Program Committee
1995 - Co-Chair, Scientific Program Committee
1996 - Program Committee
1997 - Chair, Scientific Program Committee
1998-2002 - Councillor, Executive Committee
2003-2006 - Treasurer
2004-2006 - Ad Hoc Minority Committee
2008 - Co-Chair, Committee on Investment and Audit
2008 - Co-Chair, Scientific Program Committee
2009 - Vice President
2010 - President-Elect
2011 - President
1986-present The Protein Society
1987-present American Federation for Medical Research
1987-present International Society on Thrombosis and Haemostasis
1988-2006 - Subcommittee on von Willebrand Factor, Scientific and Standardization Committee
   1988-1989 - Co-Chairman
   1992-1994 - Co-Chairman
   1994-1997 - Chairman
   2003-2006 - Chair, Working Party on von Willebrand Disease Classification
1992-1998 - Scientific and Standardization Committee Class of 1998
1996-1997 - Member-at-large, Executive Committee, Scientific and Standardization Committee
1996-2002 - Executive Council Class of 2002
1998-present - Senior Advisory Council, Scientific and Standardization Committee
1998-2003 - Chairman, Standing Committee on Publications
2007 - Scientific Program Committee, XXI ISTH Congress, Geneva
2009 - International Scientific Advisory Board, XXII ISTH Congress, Boston
2011 - Scientific Program Committee, XXIII ISTH Congress, Kyoto
1987-present American Heart Association
1987-1997 - Member, Council on Thrombosis
1997-present - Fellow, Council on Arteriosclerosis, Thrombosis, and Vascular Biology
1988-1990 - Executive Committee, Council on Thrombosis
1998-2000 - Executive Committee, Council on Arteriosclerosis, Thrombosis, and Vascular Biology
1998-1999 - Vice Chairman, Program Committee (Thrombosis Section), Council on Arteriosclerosis, Thrombosis, and Vascular Biology
1999-2000 - Chairman, Program Committee (Thrombosis Section), Council on Arteriosclerosis, Thrombosis, and Vascular Biology
1988-present American Society for Clinical Investigation
1993-present Association of American Physicians
1993-1997 NIH Hematology Study Section 1
1995-1997 - Chairman
1995-present Molecular Medicine Society
1996 Vice-Chair, Gordon Conference on Hemostasis
1998 Chair, Gordon Conference on Hemostasis
2004-2008 NIH NHLBI von Willebrand Disease Working Group
2006-2008 NCRR Protocol Review Committee for the Rare Diseases Clinical Research Network
2006 NIH NHLBI Strategic Planning Level 1 Working Group on Diagnosis and Treatment of Thrombotic Disorders
2009 NIH NHLBI State of the Science Symposium in Transfusion Medicine and Hemostasis/Thrombosis, September 14-15, 2009, Thrombosis/Hemostasis External Panel