Animals

Wild-type (WT) and Nlrp3^−/− C57BL/6 mice were purchased respectively from Charles River Laboratories International, Inc. (Wilmington, MA, USA) and Jackson Laboratory (Bar Harbor, ME, USA). Eight weeks-old male mice were assigned to a chow or an high-fat-high-carbohydrate diet (HFHC). Mice were provided ad libitum access for 12 weeks to chow (3.1 kcal/g, 18% from fat, 24% from proteins, and 58% from carbohydrates) or HFHC (5.6 kcal/g, 58% from fat, 18% from proteins, and 24% from carbohydrates; Laboratorio Piccioni, Milan, Italy) with drinking water enriched with high-fructose corn syrup equivalent (42 g/L of carbohydrates mixed in water at a ratio of 55% fructose and 45% sucrose)⁴⁹. A group of HFHC mice were also treated for 12 weeks with antibiotics to prevent growth of intestinal bacteria²⁴. Mice were housed accordingly to their treatment and genotype. Caloric intake was expressed as calories intake/body weight ratio that was calculated from the estimated quantity of calories consumed by each mouse divided by its body weight. Animal work has been conducted according to the local committee for care and use of laboratory animals. The study protocol was approved by the Ethical Committee of the “Università Politecnica delle Marche” under the protocol named FIRB07/2011GE.