Molecular Histology of EphrinA1 Expression in Mouse Heart Visualized Molecular Histology of EphrinA1 Expression in Mouse Heart Visualized with MALDI-MSI

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Justin C Parks (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: EphrinA1 is a tyrosine kinase receptor localized in the cellular membrane of healthy cardiomyocytes , the expression of which is lost upon myocardial infarction (MI). Intra-cardiac injection of the recombinant form of ephrinA1 (ephrinA1-Fc) at the time of ischemic injury in mice has shown beneficial effects by reducing tissue injury and resultant infarct size post-MI. To date , immunohistochemistry and Western blotting comprise the only experimental approaches utilized to localize and quantify relative changes of ephrinA1 in tissue sections and homogenates of whole left ventricle , respectively. Herein , we used matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) coupled with a time-of-flight mass spectrometer (MALDI/TOF MS) to identify intact ephrinA1 in cardiac tissue as well as ephrinA1 fragments that have undergone tryptic digestion. The next step for the characterization and understanding of ephrinA1's role in cardiac tissue was to develop an integrated quantitative method using MALDI-MSI technologies. For this thesis , an optimized a protocol for relative quantitation of endogenous tryptic ephrinA1 peptides detected in the healthy murine myocardium was developed using a standard curve generated with analytical standards. In healthy myocardium , there was approximately 50 ng of endogenous ephrinA1 per tissue section of 9.43 mm2 average area. MALDI-MSI thus provided a tool for the determination of not only anatomical distribution , but also relative quantitation of endogenous ephrinA1 in cardiac tissue , advancing our understanding of ephrinA1 expression profile in cardiac tissue. In order to further study ephrinA1 in cardiac tissue , MALDI-MSI was used to study the effects of ephrinA1-Fc treatment 1 , 2 , 4 , and 7 days post-MI. In addition to studying the effects of ephrinA1-Fc on endogenous expression levels of ephrinA1 post-MI , we also inquired about the possibility of gender differences in response to injury as well as EphrinA1-Fc treatment.

Additional Information

Publication

Thesis

Language: English

Date: 2018

Keywords

MALDI-MSI EphrinA1 Myocardial Infarction

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