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John Hassell, Ph.D.


Professor, Molecular Medicine

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Email: jhassell@health.usf.edu
Phone: (813) 974-7881
Office: MDC, 3014
Mailing address University of South Florida 12901 Bruce B Downs Blvd., MDC 7
Tampa, FL 33612-4799
  • PHD, BIOLOGY, University Of Connecticut, STORRS, United States - 1972.
  • BA, Biology, Central Connecticut State, USA - 1966.
Interdisciplinary & Emerging Signature Programs
Biomedical Engineering & Nanomedicine.
Research Summary

My research has focused on identifying the proteoglycans present in cartilage, basement membrane and cornea and determining their role in disease and development. My current research interest is in the extra cellular matrix (ECM) made by keratocytes during wound healing. The corneal stroma consists of an extensive extra cellular ECM interspersed with keratocytes. This ECM is uniquely transparent due to the small uniform diameter and spacing of the collagen fibrils. Wounds to the cornea readily heal but the stomal keratocytes can often produce opaque scars that cause blindness. Stromal wound healing is currently thought to consist of three major phases. First, the injured keratocytes as well as some keratocytes flanking the wound undergo apoptosis. Second, some of the surviving keratocytes are activated to proliferate and become hypercellular myofibroblasts (myofibroblasts that produce little ECM, resulting in densely packed cells). The hypercellular myofibroblasts can remain as such and produce a hypercellular scar, or they can be stimulated to produce one of two kinds of ECM: 1) a normal collagenous matrix that restores transparency, 2) a fibrocollagenous matrix that produces an opaque scar. We have found, by using keratocytes in culture that the hypercellular and collagenous phases of wound healing can be reproduced in vitro by specific growth factors. FGF-2 and TGF-beta together would produce the hypercellular phase, IGF-1 alone would produce the collagenous phase and TGF-beta alone would produce the fibrocollagenous phase. We are now using these growth factors in tissue engineering studies to produce a stromal construct for use in corneal transplantation.


Selected Publications

Positions Held
  • Professor (Biochemistry and Molecular Biology, University of South Florida 1997 - 2006)
  • Director of Research (Research Department, Shriners Hospitals for Children 1997 - 2006)
  • Professor (Secondary Appointment) (Cell Biology and Physiology, University of Pittsburgh 1997 - 1997)
  • Professor (Ophthalmology, University of Pittsburgh 1988 - 1997)
  • Professor (Secondary Appointment) (Molecular Genetics and Biochemistry, University of Pittsburgh 1988 - 1996)
  • Research Biologist (National Institute of Dental Research, NIH 1980 - 1988)
  • Research Biologist (National Eye Institute, NIH 1978 - 1980)
  • Staff Fellow (National Institute of Dental Research, NIH 1972 - 1978)

  • American Society for Biological Chemists (Member, 1987 - Present)
  • Association for Research in Vision and Ophthalmology (Member, 1979 - Present)
  • American Society for Cell Biology (Member, 1974 - Present)

  • Burroughs Wellcome Visiting Professor (University of North Dakota - 1999)
  • Berry Endowed Chair (University of South Florida - 1997)
  • Merit Award for R01 EY08104 (NIH - 1994)
  • Research Institute Award (Alcon - 1991)
  • Jules Stein Professorship (University of Pittsburgh - 1988)
  • The NIH Directors Award (NIH - 1985)
  • NIH Fellowship (University of Connecticut - 1970)
  • UCONN Fellowship (University of Connecticut - 1968)
  • Charles O'Hara Scholarship (Marquette University - 1968)
  • NDEA Title IV (Marquette University - 1967)
  • NIH Trainee (Marquette University - 1966)

Profile last modified on 03/20/2012