Sally Twining, PhDSally Twining, PhD

Professor of Biochemistry
Professor of Ophthalmology

(414) 456-8431
(414) 456-6510 (fax)

Medical College of Wisconsin
Department of Biochemistry
8701 Watertown Plank Road
Milwaukee, WI 53226

Sally Twining, PhD is interested in the mechanism of corneal ulceration and means for controlling corneal degradation. Corneal ulceration can be induced by bacteria, viruses, autoimmune reactions, nutritional deficiencies, chemical injuries and genetic deficiencies. Degradation of the cornea occurs when there is an imbalance between proteinases, enzymes that degrade the cornea, and proteinase inhibitors. This imbalance can occur due to over synthesis of proteinases or inhibition of synthesis of proteinase inhibitors by the cornea or release of proteinase from bacteria or inflammatory cells. Dr. Twining's research centers around corneal ulceration due to Pseudomonas aeruginosa and vitamin A deficiency. As part of this research, the mechanisms by the cornea defends itself against degradation are studied. Understanding the molecular basis of corneal ulceration and how the normal cornea protects itself will lead to better ways of treating corneal ulceration.

Recently Dr. Twining's laboratory characterized a more active form of Pseudomonas elastase that is synthesized by 85% of the Pseudomonas aeruginosa organisms recovered from ulcerating corneas. Her laboratory also showed that the cornea can synthesize molecules that usually are synthesized by the liver and distributed to the tissues through the circulatory system. These include the proteinase that degrades fibrin, plasmin, and the proteinase inhibitors, (1-proteinase inhibitor ((1-antitrypsin), (1-antichymotrypsin and (2-macroglobulin. Plasmin is required for remodeling of the cornea following injury and inflammation. The proteinase inhibitors protect the cornea from degradation by proteinases are synthesized by the cornea and those released by inflammatory cells. In collaboration with Dr. Beatrice Yue at the University of Illinois School of Medicine, the pathogenesis of keratoconus, a corneal thinning disease, was shown to involve an imbalance between proteinases and inhibitors.


  • PhD, Physiological Chemistry, Ohio State University

Post Doctoral Training

  • Immunology, Mayo Clinic Foundation

  • Biochemistry, Medical College of Wisconsin

Current Research Interests

  • Role of Proteinases in Corneal Ulceration

  • Effects of Vitamin A on the Cornea

  • Mechanism of Action of Proteinase Inhibitors

Honors and Society Memberships

  • Member, Visual Science A, NIH Study Section (1994-1998)

  • Grant Reviewer, USDA, NSF (1991-present)

  • American Association for Advancement of Science

  • American Chemical Society

  • American Society for Biochemistry and Molecular Biology

  • Association for Research in Vision and Ophthalmology

  • Sigma Xi

Recent Publications


Medical College of Wisconsin
8701 Watertown Plank Road
Milwaukee, WI 53226
(414) 955-8296
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