Evaluation of systemic and tissue-specific inflammation as risk factor for atherosclerosis in pigs fed with high-fat diet

Background and Aims: It has been established that the inflammatory component represents a significant contribution in the background of clinically recognizable risk factors of atherosclerosis, for example, hypertension, hyperglycemia, dyslipidemia, obesity. The aim of this study was to evaluate systemic and tissue-specific inflammation in pigs fed with high-fat diet. Methods: 21 pigs were kept for 16 weeks on a standard diet (SD; 3.6% lipids; n = 7) or a high-fat diet (HFD; 22% lipids, 5% cholesterol; n = 14). Seven HFD fed pigs received high-dose atorvastatin (80 mg/die) starting after 8 weeks of hypercholesterolemic diet until the end of the experimental procedure. Results: HFD administration significantly raised the number of circulating leukocytes, leading to a “hypercholesterolemia-associated monocytosis” and promoting the synthesis of several pro-inflammatory molecules. Hypercholesterolemia induced adipocytes hypertrophy and T-lymphocytes infiltration in abdominal white adipose tissue (WAT). HFD-fed pigs displayed liver inflammation, hepatic stellate cells activation with a concomitant increased infiltration of macrophages, T- and B-lymphocytes. Inflammation extended beyond liver and WAT with increased macrophage content in lung parenchyma. Atorvastatin abolished WAT inflammation by reducing adipocyte area and the number of infiltrating T-lymphocytes. In the liver, atorvastatin decreased hepatic stellate cells activation and the inflammatory infiltrate and lowered the amount of macrophages in lung parenchima of HFD-fed pigs. Conclusion: Hypercholesterolemia significantly raised the amount of circulating leukocytes and exacerbated the inflammatory response in WAT, liver and lung. Atorvastatin treatment markedly decreased systemic and tissue-specific inflammatory markers by preventing the development of an inflammatory milieu and the accumulation of infiltrating leukocytes