RNA Cloning and Visualization in Human Atherosclerosis

Clinical Trial Summary

The research objectives of this project are as follows:

1. Obtain high-quality human atherosclerotic arterial samples from diseased donors.

2. Perform biochemical analysis to determine the abundance, localization and activity of Dicer and double-stranded RNAs in these diseased tissues.

Participants enrolled in to this pilot study will not be randomized and will not receive any investigation medication.

In collaboration with Dr. Sibu Saha, Professor of Surgery, University of Kentucky, the investigator will obtain freshly isolated human atherosclerotic tissue from patients undergoing carotid endarterectomy. The surgical process by which the tissue is obtained is not part of this research project. These tissues are surgically removed from patients as a treatment for atherosclerosis of the carotid arteries and typically sent for pathological examination.

After the the clinical pathology has been completed, the investigator will obtain and analyze a small amount of discarded (200mg) tissue. Subsequent analyses will be performed on the basis of the pathological grading provided by UK Pathology (e.g do readouts of the Dicer pathway correlate with pathological plaque characteristics). Tissue will be anonymized, with only information with respect to drug history, age, gender and pathological grade of the tissue.

The will extract protein and RNA. Dicer abundance will be assessed by western blot, quantitative RT-PCR and northern blot. Dicer related RNAs will be measured by quantitative RT-PCR and northern blot. The invesigator will inspect the tissue for evidence of altered Dicer activity by measuring the relative levels of abundant canonical Dicer substrates/enzymatic products (i.e. the ratio of pre- to mature micro-RNA) via northern blot. The investigator predicts that Dicer levels and activity are reduced in human atherosclerotic tissue compared to healthy arteries.

Next, the investigator will assess whether downstream mediators of Dicer dysregulation are activated in these tissue samples by comparing levels and activation of the inflammasome (caspase-1, NLRP3, ASC), cytokines (IL-1β, IL-18) and signaling intermediates (MyD88, IRAK1/4) between healthy and diseased tissues. The investigator predicts that atherosclerotic plaques will exhibit evidence of Dicer dysregulation.

Next, the investigator will co-stain tissue sections with antibodies recognizing Dicer as well as cell-specific markers (CD31 for endothelium, SMA for smooth muscle, MAC-1 for macrophages) to assess whether Dicer dysregulation displays cell type-specific patterns. ;

Study Design

Related Conditions & MeSH terms

• Atherosclerosis