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A Gene Expression Profile of Metabolic Dysfunction in the Aorta of Male Sprague‐Dawley Rats Following a Short‐Term High‐Fat Diet
Author(s) -
Mohr Alex E.,
Reiss Rebecca A.,
Sena Johnny,
Naik Jay S.,
Walker Benjimen R.,
Sweazea Karen L.
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.06178
Subject(s) - biology , endocrinology , medicine , gene expression , gene , diabetes mellitus , aorta , candidate gene , genetics
Diet‐induced metabolic dysfunction precedes multiple disease states, including diabetes, heart disease, and atherosclerosis. The critical role of the vasculature in disease progression is established, yet the details of gene expression remain an enigma. The objective of the current project was to demonstrate that a quantitative assessment of gene expression within the vascular wall (aorta) of healthy rats compared to those exhibiting metabolic dysfunction symptoms could reveal potential mediators of vascular dysfunction. RNA was extracted from the aorta of four rats from a larger experiment; two animals that were maintained on a high‐fat diet (HFD) exhibited symptoms of metabolic dysfunction (including hypertension, weight gain, glucose intolerance, and insulin insensitivity) and two healthy animals that were fed a standard chow diet (CHOW) served as age‐matched controls. Poly‐A libraries were constructed and subjected to Illumina sequencing protocols. The post‐sequencing workflow was conducted with the software package Lumenogix® and sequencing reads were mapped to the Rat Genome Assembly version Rnor_5.0 using the Genomic Mapping and Alignment Program (GMAP). The program Empirical Analysis of Digital Gene Expression data in R (EdgeR) was used to evaluate statistical significance. Genes with a P adjusted value of ≤ 0.05 were passed to Cytoscape App ClueGO/CluePedia for enrichment analysis using Gene Ontology (GO) Biological Process terms, network construction and visualization. Preliminary analyses indicated 93 genes were significantly differentially expressed in the aorta of HFD rats. Enrichment analysis and the resulting network contained 54 genes relevant to physiological processes including fat and protein metabolism, oxygen transport, hormone regulation, vascular regulation, thermoregulation, and circadian rhythm. The majority of differentially regulated genes were downregulated (82.5%) including Nicotinamide Phosphoribosyltransferase (visfatin), which plays a role in the modulation of the circadian clock function. In contrast, Leptin and 3‐hydroxy‐3‐methylglutaryl‐CoA synthase 2 (Hmgcs2) were notably upregulated. Leptin is involved in several major energy balance signaling pathways and Hmgcs2 is a mitochondrial enzyme that catalyzes the first reaction of ketogenesis. Together, these data describe the changes in gene expression within the aortic wall of HFD rats with early metabolic dysfunction and highlight potential pathways and signaling intermediates that impact vascular disease.