Mechanisms of Resistance to Apoptosis in Scleroderma Skin Fibroblasts

Thomas Jefferson University, Philadelphia PA

Investigators

Abstract

[unreadable] DESCRIPTION (provided by applicant): Dr. Sandorfi is a rheumatologist with keen interest in clinical and basic research specifically related to systemic sclerosis (SSc). She obtained her basic research and clinical training at the Thomas Jefferson University, Scleroderma Research Center. She has a very strong commitment to continuing scholarly and academic activities in SSc research and eventually become an independent investigator. The Career Development Award would provide her the opportunity to obtain in-depth training and conduct studies that will enable her to become an independent researcher. Thomas Jefferson University provides an outstanding research environment and high quality training opportunities. The outlined research plan is novel and has a great potential to provide a strong foundation for further investigations. SSc is associated with increased deposition of certain matrix proteins in the skin and internal organs. Apoptosis and its regulating intracellular proteins have not been a major focus of interest in SSc despite several indications of the role they may play in the development of the disease. It has recently been recognized that: SSc fibroblasts are resistant to Fas-mediated apoptosis; SSc fibroblasts are resistant to anti- Fas antibody-induced apoptosis following sustained exposure to TGF-/3 a higher proportion of skin fibroblasts are p-Akt positive in biopsies from SSc. These results indicate that elements of the intracellular signaling pathways of apoptosis should be further explored. Our hypothesis is that dysregulation of elements of the intracellular signaling pathways plays an important role in the attenuated apoptosis of skin fibroblasts in SSc, which in turn may cause the exaggerated collagen production. In this project we propose to perform a step-by-step analysis of the extrinsic apoptotic pathway in the presence and absence of TGF-/2 we will study caspase-8 activation, mitochondrial membrane permeabilization induced by tBid, ceramide/calcium, and Akt aktivity. The studies will be carried out on live SSc fibroblasts employing fluorescent microscopy, fluorescent single cell analysis, and basic biochemical methods. Relevance: SSc is a devastating disease still of unknown origin and without effective treatment. Investigating the mechanisms why SSc skin cells die slower may provide a deeper understanding of how this disease develops. These studies may provide valuable information for the development of novel and successful treatment. [unreadable] [unreadable] [unreadable] [unreadable]