Curbing High‐Fat Induced Perturbations in Aortic Perivascular Adipose Tissue in Adolescent Male Sprague‐Dawley Rats: Soil as Therapy?

Abstract

Directly attached to the outer wall of blood vessels, perivascular adipose tissue (PVAT) is a unique variant of fat that is an important paracrine modulator of vascular physiology. Due to the proximity and endocrine‐like characteristics of this tissue, PVAT can contribute to the regulation vascular contractility and endothelial function. PVAT can also assume several properties of brown adipose tissue, including increased vascularization, small lipid droplet formation, mitochondrial density, and production of cardiometabolic signaling intermediates. Importantly, these properties promote the metabolic activity of this tissue which appear to be associated with improved vascular health. However, such properties may be diminished by chronic deleterious stimuli such as a high‐fat diet (HFD) and disease conditions like metabolic syndrome. Under such pressures, PVAT may serve a more insidious role in vascular dysfunction and promote the development of cardiovascular disease. Chronic diet‐induced changes in the vasculature and associated tissues like PVAT may be occurring early in the life cycle, promoting degeneration and disease‐associated remodeling. Currently, examination of these tissues early in life remain relatively unexplored and may offer important insight into the identification of prevention strategies and therapeutic targets. Previously, our lab identified increased expression of genes in the aorta of HFD fed adolescent Sprague‐Dawley rats, highlighting potential pathways and signaling intermediates that may impact the development of early vascular dysfunction. Moreover, we have demonstrated that an organic mineral complex (OMC) derived from plant and soil fractions prevented symptoms of metabolic syndrome in these animals. OMC is a complex of minerals, trace elements, organic acids (particularly fulvic acid), nitrates, and various microbial degradation products from plant and animal origins. The objective of the current study is to investigate the effects of a HFD and OMC on the expression of key proteins in aortic PVAT that play a role in adipose beiging, metabolism, and mitochondrial biogenesis, and are thus expected to provide critical insight into early mitigation of vascular disease progression. Six‐week‐old male Sprague‐Dawley rats (n = 36) were divided into two dietary groups: Chow or HFD fed for 10 weeks. Animals were further divided (n = 6/group) and administered 0, 0.6, or 3.0 mg/mL OMC in their drinking water. After the 10‐week intervention PVAT surrounding the aorta was extracted from the animals and Western blot analyses were performed using antibodies for the proteins UCP1, SDHA, PI3K, GLUT4, and b‐actin (as a loading control). Overall, we hypothesize that OMC supplementation will minimize decreases in these key proteins involved in health associated PVAT metabolism and function.