Browsing by Author "Viana, Sofia"
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- Blueberry juice as a nutraceutical approach to prevent prediabetes progression in an animal model: focus on hepatic steatosisPublication . Nunes, Sara; Viana, Sofia; Rolo, Anabela; Palmeira, Carlos; André, Alexandra; Cavadas, Claudia; Pintado, Manuela; Reis, Flávio
- Crescent-like lesions as an early signature of nephropathy in a rat model of prediabetes induced by a hypercaloric dietPublication . Nunes, Sara; Alves, André; Preguiça, Inês; Barbosa, Adelaide; Vieira, Pedro; Mendes, Fernando; Martins, Diana; Viana, Sofia; Reis, FlávioDiabetic nephropathy (DN) is a major microvascular complication of diabetes. Obesity and hyperlipidemia, fueled by unhealthy food habits, are risk factors to glomerular filtration rate (GFR) decline and DN progression. Several studies recommend that diabetic patients should be screened early (in prediabetes) for kidney disease, in order to prevent advanced stages, for whom the current interventions are clearly inefficient. This ambition greatly depends on the existence of accurate early biomarkers and novel molecular targets, which only may arise with a more thorough knowledge of disease pathophysiology. We used a rat model of prediabetes induced by 23 weeks of high-sugar/high-fat (HSuHF) diet to characterize the phenotype of early renal dysfunction and injury. When compared with the control animals, HSuHF-treated rats displayed a metabolic phenotype compatible with obese prediabetes, displaying impaired glucose tolerance and insulin sensitivity, along with hypertriglyceridemia, and lipid peroxidation. Despite unchanged creatinine levels, the prediabetic animals presented glomerular crescent-like lesions, accompanied by increased kidney Oil-Red-O staining, triglycerides content and mRNA expression of IL-6 and iNOS. This model of HSuHF-induced prediabetes can be a useful tool to study early features of DN, namely crescent-like lesions, an early signature that deserves in-depth elucidation.
- Effects of statins therapy on LDL subfractions and inflammation in end-stage renal disease patients on dialysisPublication . Coimbra, Susana; Reis, Flávio; Nunes, Sara; Viana, Sofia; Valente, Maria João; Rocha, Susana; Catarino, Cristina; Rocha-Pereira, Petronila; Bronze-da-Rocha, Elsa; Oliveira, José Gerardo; Madureira, José; Fernandes, João Carlos; Do Sameiro-Faria, Maria; Miranda, Vasco; Belo, Luís; Santos-Silva, Alice
- Impact of dietary sugars on gut microbiota and metabolic healthPublication . Garcia, Karina; Ferreira, Gonçalo; Reis, Flávio; Viana, SofiaExcessive sugar consumption is a risk factor for the development of several disorders, including metabolic, cardiovascular, neurological conditions and even some cancers, and has been linked to increased morbidity and mortality. The popularization of the typical Western diet, featured by an excessive intake of saturated fats and added sugars and a low consumption of unprocessed fruits, vegetables and fiber, may directly affect the composition and functionality of the gut microbiota, staggering the balance of the intestinal microbiome that ultimately culminates into gut dysbiosis. Although added sugars in the form of nutritive and non-nutritive sweeteners are generally considered as safe, a growing body of evidence correlate their consumption with adverse effects on gut microbial ecosystem; namely an abnormal synthesis of short-chain fatty acids, altered intestinal barrier integrity and chronic inflammation that often fuel a panoply of metabolic conditions. Accordingly, this work revisited the available preclinical evidence concerning the impact of different types of dietary sugars—nutritive and non-nutritive sweeteners—on gut microbiota and metabolic health. Future research should consider gender and species vulnerability when the impact of such substances on GM community and metabolic health is scrutinized in order to guide their adequate use at doses relevant to human use.
- A novel semi-solid pill for stress-free voluntary oral drug administration in experimental rodentsPublication . Viana, Sofia; Martins, B.; Nunes, S.; Palavra, F.; Preguiça, I.; Alves, A.; Nóbrega, C.; Fernandes, R.; Silva, S.; Barbosa Moreira, Zélia; Lima, D.L.D.; Fontes-Ribeiro, Carlos; Reis, FlávioDuring compound screening and drug development, long-term oral drug administration to experimental rodents is often required. Oral gavage, a straightforward drug dosing technique, is not suitable for extended treatments considering the recurrent traumatic complications (gastroesophageal injury) and physiological distress (corticosterone levels alterations) that frequently bias experimental design outcomes. These reasons create a challenge for preclinical drug assays and stress-free/metabolic-inert alternatives of oral drug administration are warranted. Herein, it is presented an innovative semi-solid pill optimized to overcome aforementioned drawbacks. After a brief training period, C57BL/6 mice submitted to a chronic oral administration protocol (50 days) displayed a high index of voluntary acceptance of emptyand drug- (e.g. sitagliptin) incorporated vehicle in both healthy and CNS-diseased states. This protocol operates in a pair-housed animal housing fashion, allowing animal socialization throughout entire protocol. At the end of experiments, a normal neurobehavioral phenotype (anxiolytic, memory, locomotion parameters) was recorded. Moreover, this new methodology proved to be safe, preserving serum metabolic (glucose, triglycerides, total cholesterol), hepatic (albumin, total proteins) and renal (urea, creatinine, uric acid) parameters along with normal ileum contractility. Remarkably, coherent sitagliptin ( 10 mg/ml) plasma levels were detected, along with a robust decrease ( 80%) on the activity of its target (dipeptidyl peptidase- 4), unequivocally proving in vivo drug efficacy. Overall, this innovative approach may enclose a breakthrough advance for translational studies in scientific and pharmaceutical fields, providing a reproducible, efficient, metabolic inert and stress-free alternative for voluntary oral drug administration, with expected improvement on the data feasibility.
- The protective role of adiponectin for lipoproteins in end-stage renal disease patients: relationship with diabetes and body mass indexPublication . Coimbra, Susana; Reis, Flávio; Nunes, Sara; Viana, Sofia; Valente, Maria João; Rocha, Susana; Catarino, Cristina; Rocha-Pereira, Petronila; Bronze-da-Rocha, Elsa; Sameiro-Faria, Maria; Oliveira, José Gerardo; Madureira, José; Fernandes, João Carlos; Miranda, Vasco; Belo, Luís; Santos-Silva, AliceCardiovascular disease (CVD) events are the main causes of death in end-stage renal disease (ESRD) patients on dialysis. The number and severity of CVD events remain inappropriate and difficult to explain by considering only the classic CVD risk factors. Our aim was to clarify the changes and the relationship of lipoprotein subfractions with other CVD risk factors, namely, body mass index (BMI) and adipokines, inflammation and low-density lipoprotein (LDL) oxidation, and the burden of the most prevalent comorbidities, diabetes mellitus (DM) and hypertension (HT). We studied 194 ESRD patients on dialysis and 22 controls; lipid profile, including lipoprotein subpopulations and oxidized LDL (oxLDL), C-reactive protein (CRP), adiponectin, leptin, and paraoxonase 1 activity were evaluated. Compared to controls, patients presented significantly lower levels of cholesterol, high-density lipoprotein cholesterol (HDLc), LDLc, oxLDL, and intermediate and small HDL and higher triglycerides, CRP, adiponectin, large HDL, very-low-density lipoprotein (VLDL), and intermediate-density lipoprotein- (IDL) B. Adiponectin levels correlated positively with large HDL and negatively with intermediate and small HDL, oxLDL/LDLc, and BMI; patients with DM (n = 17) and with DM+HT (n = 70), as compared to patients without DM or HT (n = 69) or only with HT (n = 38), presented significantly higher oxLDL, oxLDL/LDLc, and leptin and lower adiponectin. Obese patients (n = 45), as compared to normoponderal patients (n = 81), showed lower HDLc, adiponectin, and large HDL and significantly higher leptin, VLDL, and intermediate and small HDL. In ESRD, the higher adiponectin seems to favor atheroprotective HDL modifications and protect LDL particles from oxidative atherogenic changes. However, in diabetic and obese patients, adiponectin presents the lowest values, oxLDL/LDLc present the highest ones, and the HDL profile is the more atherogenic. Our data suggest that the coexistence of DM and adiposity in ESRD patients on dialysis contributes to a higher CVD risk, as showed by their lipid and adipokine profiles.