Graduation Year

2015

Graduation Month

May

Document Type

Thesis

Degree Name

Bachelor of Arts

School or Department

Biological Sciences, Division of

Major

Biology – Human Biological Sciences

Faculty Mentor

Dr. Elizabeth A. Putnam

Faculty Mentor Department

Biomedical and Pharmaceutical Sciences

Keywords

SPARC, asbestos, pulmonary fibrosis, RNA interference, shRNA, gene knockdown

Subject Categories

Biological Phenomena, Cell Phenomena, and Immunity | Medical Cell Biology | Medical Molecular Biology | Pharmacology, Toxicology and Environmental Health

Abstract

The adverse health effects of exposure to asbestos are widely known and have been well documented. When a person is diagnosed with asbestosis, a chronic lung disease caused by inhaling asbestos fibers, few treatment options exist, none of which halt or reverse the progression of the disease. The rapidly growing field of gene therapy offers new avenues for potential treatments worthy of investigation. The detrimental effects of asbestos exposure are due to the physiological response of the lungs to asbestos fibers in the form of fibrosis, a result of excess extracellular collagen deposition. A protein called SPARC (Secreted Protein Acidic and Rich in Cysteine) has been identified in previous studies as being a matricellular protein involved in the fibrotic response following asbestos exposure. Using the principle of RNA interference, we aimed to knock down the expression of SPARC in our studies, hypothesizing that a reduction in SPARC expression would yield a reduction in fibrosis. In our in vitro experiments, we prepared several viral constructs containing a SPARC-specific short hairpin RNA (shRNA), and identified the most effective construct using primary mouse lung fibroblasts. The most effective construct was used to infect asbestos-exposed and control mice. The presence of fibrosis was measured in three distinct ways:

  1. Histologically to visually observe the presence of fibrosis,
  2. Using RT-PCR to measure the presence of SPARC mRNA,
  3. Using a Western Blot to measure the presence of collagen.

We expected to observe that the mice treated with the SPARC shRNA containing virus experienced less fibrosis, and had less SPARC mRNA and collagen present in their lungs than control mice. Unfortunately, none of the mice in our study developed fibrosis after asbestos exposure, as had been previously demonstrated. We intend to reevaluate our instillation method, among other procedures, before proceeding with future studies.

Honors College Research Project

Yes

 

© Copyright 2015 Sarah Kinsey