Colon transcriptome is modified by a dietary pattern/atorvastatin interaction in the Ossabaw pig

Optimizing diet quality in conjunction with statin therapy is currently the most common approach for coronary artery disease (CAD) risk management. Although effects on the cardiovascular system have been extensively investigated, little is known about the effect of these interventions in the colon and subsequent associations with CAD progression. To address this gap, Ossabaw pigs were randomly allocated to receive, for a six-month period, isocaloric amounts of either a heart healthy-type diet (HHD; high in unrefined carbohydrate, unsaturated fat, fiber, supplemented with fish oil, and low in cholesterol) or a Western-type diet (WD; high in refined carbohydrate, saturated fat and cholesterol, and low in fiber), without or with atorvastatin therapy. At the end of the intervention period, colon samples were harvested, mucosa fraction isolated, and RNA sequenced. Gene differential expression and enrichment analyses indicated that dietary patterns and atorvastatin therapy differentially altered gene expression, with diet-statin interactions. Atorvastatin had a more profound effect on differential gene expression than diet. In pigs not receiving atorvastatin, the WD upregulated “LXR/RXR Activation” pathway compared to pigs fed the HHD. Enrichment analysis indicated that atorvastatin therapy lowered inflammatory status in the HHD-fed pigs, whereas it induced a colitis-like gene expression phenotype in the WD-fed pigs. No significant association was identified between gene expression phenotypes and severity of atherosclerotic lesions in the left anterior descending-left circumflex bifurcation artery. These data suggested diet quality modulated the response to atorvastatin therapy in colonic mucosa, and these effects were unrelated to atherosclerotic lesion development.

Western and heart healthy dietary patterns differentially affect the expression of genes associated with lipid metabolism, interferon signaling and inflammation in the jejunum of Ossabaw pigs

Diet quality and statin therapy are established modulators of coronary artery disease (CAD) progression, but their effect on the gastrointestinal tract and subsequent sequelae that could affect CAD progression are relatively unexplored. To address this gap, Ossabaw pigs (N = 32) were randomly assigned to receive isocaloric amounts of a Western-type diet (WD; high in saturated fat, refined carbohydrate, and cholesterol, and low in fiber) or a heart healthy-type diet (HHD; high in unsaturated fat, whole grains, fruits and vegetables, supplemented with fish oil, and low in cholesterol), with or without atorvastatin, for 6 months. At the end of the study, RNA sequencing with 100 base pair single end reads on NextSeq 500 platform was conducted in isolated pig jejunal mucosa. A two-factor edgeR analysis revealed that the dietary patterns resulted in three differentially expressed genes related to lipid metabolism (SCD, FADS1, and SQLE). The expression of these genes was associated with cardiometabolic risk factors and atherosclerotic lesion severity. Subsequent gene enrichment analysis indicated the WD, compared to the HHD, resulted in higher interferon signaling and inflammation, with some of these genes being significantly associated with serum TNF-α and/or hsCRP concentrations, but not atherosclerotic lesion severity. No significant effect of atorvastatin therapy on gene expression, nor its interaction with dietary patterns, was identified. In conclusion, Western and heart healthy-type dietary patterns differentially affect the expression of genes associated with lipid metabolism, interferon signaling, and inflammation in the jejunum of Ossabaw pigs.

A Case for Porcine Respiratory Coronavirus and the Obese Ossabaw Pig

The ongoing COVID-19 pandemic caused by infection with SARS-CoV-2 has created an urgent need for animal models to enable study of basic infection and disease mechanisms and for development of vaccines, therapeutics, and diagnostics. Most research on animal models for COVID-19 has been directed toward rodents, transgenic rodents, and non-human primates. The primary focus has been on the angiotensin-converting enzyme 2 (ACE2), which is a host cell receptor for SARS-CoV-2. Among investigated species, irrespective of ACE2 spike protein binding, only mild (or no) disease has occurred following infection with SARS-CoV-2, suggesting that ACE2 may be necessary for infection but is not sufficient to determine the outcome of infection. The common trait of all species investigated as COVID models is their healthy status prior to virus challenge. In contrast, the vast majority of severe COVID-19 cases occur in people with chronic comorbidities such as diabetes, obesity, and/or cardiovascular disease. Healthy pigs express ACE2 protein that binds the viral spike protein but they are not susceptible to infection with SARS-CoV-2. However, certain pig breeds, such as the Ossabaw pig, can reproducibly be made obese and show most aspects of the metabolic syndrome, thus resembling the more than 80% of the critically ill COVID-19 patients admitted to hospitals. We urge considering infection with porcine respiratory coronavirus of metabolic syndrome pigs, such as the obese Ossabaw pig, as a highly relevant animal model of severe COVID-19.

A Western-Type Dietary Pattern Induces an Atherogenic Gene Expression Profile in the Coronary Arteries of the Ossabaw Pig

BACKGROUND

Current cardiovascular risk reduction guidance focuses on shifts in dietary patterns, rather than single foods or nutrients. Experimental studies are needed to identify the mechanisms by which food-based diets affect the development and progression of atherosclerosis.

OBJECTIVES

The aim of this study was to investigate the effect of 2 food-based dietary patterns and statin therapy on the transcriptome of the left anterior descending coronary artery of the Ossabaw pig.

METHODS

Pigs were randomly assigned to 1 of 4 groups and fed isocaloric diets for 6 mo; Heart Healthy-style diet (HHD) (high in unsaturated fat, unrefined grain, fruits/vegetables) or Western-style diet (WD) (high in saturated fat, cholesterol, refined grain), with or without atorvastatin. A 2-factor edge R analysis was used to determine differential gene expression in the left anterior descending coronary artery.

RESULTS

Relative to the HHD, the WD resulted in the differential expression of 143 genes, of which 139 genes were upregulated and 4 genes were downregulated (all log fold change ≥0.6, false discovery rate <0.10). The WD, compared with the HHD, resulted in the statistically significant upregulation of 8 atherosclerosis-associated pathways implicated in immune and inflammatory processes. There were no genes with significant differential expression attributable to statin therapy.

CONCLUSIONS

These data suggest that a WD induces alterations in the transcriptome of the coronary artery consistent with an inflammatory atherogenic phenotype in the Ossabaw pig with no significant modification by concurrent statin therapy.

A Western-type dietary pattern and atorvastatin induce epicardial adipose tissue interferon signaling in the Ossabaw pig

Epicardial adipose tissue (EAT) inflammation is thought to potentiate the development of coronary artery disease (CAD). Overall diet quality and statin therapy are important modulators of inflammation and CAD progression. Our objective was to examine the effects and interaction of dietary patterns and statin therapy on EAT gene expression in the Ossabaw pig. Pigs were randomized to 1 of 4 groups; Heart Healthy diet (high in unsaturated fat, unrefined grain, fruits/vegetables [HHD]) or Western diet (high in saturated fat, cholesterol, refined grain [WD]), with or without atorvastatin. Diets were fed in isocaloric amounts for 6 months. A two-factor edge R analysis identified the differential expression of 21 genes. Relative to the HHD, the WD resulted in a significant 12-fold increase of radical s-adenosyl methionine domain containing 2 (RSAD2), a gene induced by interferon signaling. Atorvastatin led to the significant differential expression of 17 genes predominately involved in interferon signaling. Results were similar using the Porcine Translational Research Database. Pathway analysis confirmed the up-regulation of interferon signaling in response to the WD and atorvastatin independently. An expression signature of the largely interferon related differentially expressed genes had no predictive capability on a histological assessment of atherosclerosis in the underlying coronary artery. These results suggest that a WD and atorvastatin evoke an interferon mediated immune response in EAT of the Ossabaw pig, which is not associated with the presence of atherosclerosis.