Diet-induced obesity in C57BL/6 mice triggers common features of human metabolic syndrome (MetS). The purpose is to assess the suitability of a diet-induced obesity model for investigating non-alcoholic fatty pancreatic disease (NAFPD), fatty liver and insulin resistance. Adult C57BL/6 mice were fed either high-fat chow (HFC, 60% fat) or standard chow (SC, 10% fat) during a 16-week period. We evaluated in both groups: hepatopancreatic injuries, pancreatic islets size, alpha and beta-cell immunodensities, intraperitoneal insulin tolerance test (IPITT) and oral glucose tolerance test (OGTT). The HFC mice displayed greater mass gain (p<0.0001) and total visceral fat pads (p<0.001). OGTT showed impairment of glucose clearance in HFC mice (p<0.0001). IPITT revealed insulin resistance in HFC mice (p<0.0001). The HFC mice showed larger pancreatic islet size and significantly greater alpha and beta-cell immunodensities than SC mice. Pancreas and liver from HFC were heavier and contained higher fat concentration. In conclusion, C57BL/6 mice fed a high-fat diet develop features of NAFPD. Insulin resistance and ectopic accumulation of hepatic fat are well known to occur in MetS. Additionally, the importance of fat accumulation in the pancreas has been recently highlighted. Therefore, this model could help to elucidate target organ alterations associated with metabolic syndrome.

Dengue is a mosquito-borne viral disease caused by the dengue virus (DENV1-4). The clinical manifestations range from asymptomatic to life-threatening dengue hemorrhagic fever (DHF) and/or Dengue Shock Syndrome (DSS). Viral and host factors are related to the clinical outcome of dengue, although the disease pathogenesis remains uncertain. The innate antiviral response to DENV is implemented by a variety of immune cells and inflammatory mediators. Blood monocytes, dendritic cells (DCs) and tissue macrophages are the main target cells of DENV infection. These cells recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs). Pathogen recognition is a critical step in eliciting the innate immune response. Toll-like receptors (TLRs) are responsible for the innate recognition of pathogens and represent an essential component of the innate and adaptive immune response. Ten different TLRs are described in humans, which are expressed in many different immune cells. The engagement of TLRs with viral PAMPs triggers downstream signaling pathways leading to the production of inflammatory cytokines, interferons (IFNs) and other molecules essential for the prevention of viral replication. Here, we summarize the crucial TLRs’ roles in the antiviral innate immune response to DENV and their association with viral pathogenesis.

Metabolic syndrome (MS) is a constellation of risk factors that raise the risk for heart disease and other health problems, such as obesity. The clustering of metabolic abnormality is closely related to oxidative stress and inflammation, as well as the progression of atherosclerosis. Antioxidants are reducing agents which inhibit the oxidation of other molecules and can be used not only to prevent but also to treat health complications of MS and atherosclerosis. They can be ingested in the normal diet, since they are found in many food sources, or in supplement formulations. Herein, we aim to review the literature concerning the effect of antioxidants on MS. We focus on antioxidants with some evidence of action on this condition, like flavonoids, arginine, vitamin C, vitamin E, carotenoids, resveratrol and selenium. Experimental and clinical studies show that most of the above-mentioned antioxidants exhibit a wide range of effects in protecting the human body, especially in MS patients. However, the underlying mechanisms are not fully elucidated for most of these compounds. Also, some of them should be used with caution because their excess can be toxic to the body. In general, antioxidants (especially those present in foods) can be used by MS individuals because of their direct effect on oxidative stress. Additionally, they should be encouraged as part of a nutritional lifestyle change, since this is part of the therapy for all diseases involved in metabolic disorders.