Defense Date

2020

Document Type

Thesis

Degree Name

Master of Science

Department

Physiology and Biophysics

First Advisor

Martin Mangino

Abstract

Organ transplants are a necessary intervention for many diseases that result in end stage organ failure. The donation pool cannot match the demands of the transplant list, so expanding the pool to include donation after cardiac death (DCD) is desired. However, there are increased odds of graft failure and ischemic cholangiopathy leading to inferior outcomes when DCD livers are used. Ischemic cholangiopathy consists of multiple diffuse strictures and fibrosis of the bile ducts leading to a loss of epithelialization and fibrosis. The cellular mechanism is proposed to be epithelial-to-mesenchymal transition (EMT). TGF-𝛽 is seen as a key initiator of EMT, especially following ischemic reperfusion injury. To determine if TGF-𝛽 is an inducer of EMT, cell migration assays were performed with human cholangiocytes exposed to warm and cold ischemia (DCD conditions) and tested for TGF-𝛽 expression using western blots, RT-PCR and immunocytochemistry. An inhibitor of TGF-𝛽 was also used to show causation. The human cholangiocytes displayed migratory behavior following exposure to DCD conditions as well as an increase in TGF-𝛽 expression. Cell morphology also transitioned with a loss of epithelial, cuboidal, characteristics and a gain of mesenchymal, spindle shaped, characteristics. Prior exposure to the TGF-𝛽 receptor antagonist prevented increased migration of the cells and retention of the epithelial appearance. Our findings indicate TGF-𝛽 plays a major and causative role in the transition of cholangiocytes into mesenchymal cells.

Rights

Β© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

8-4-2020

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