RESUMO
AIMS: The consumption of highly refined carbohydrates increases systemic inflammatory markers, but its potential to exert direct myocardial inflammation is uncertain. Herein, we addressed the impact of a high-refined carbohydrate (HC) diet on mice heart and local inflammation over time. MAIN METHODS: BALB/c mice were fed with a standard chow (control) or an isocaloric HC diet for 2, 4, or 8 weeks (HC groups), in which the morphometry of heart sections and contractile analyses by invasive catheterization and Langendorff-perfused hearts were assessed. Cytokines levels by ELISA, matrix metalloproteinase (MMP) activity by zymography, in situ reactive oxygen species (ROS) staining and lipid peroxidation-induced TBARS levels, were also determined. KEY FINDINGS: HC diet fed mice displayed left ventricular hypertrophy and interstitial fibrosis in all times analyzed, which was confirmed by echocardiographic analyses of 8HC group. Impaired contractility indices of HC groups were observed by left ventricular catheterization, whereas ex vivo and in vitro indices of contraction under isoprenaline-stimulation were higher in HC-fed mice compared with controls. Peak levels of TNF-α, TGF-ß, ROS, TBARS, and MMP-2 occur independently of HC diet time. However, a long-lasting local reduction of the anti-inflammatory cytokine IL-10 was found, which was linearly correlated to the decline of systolic function in vivo. SIGNIFICANCE: Altogether, the results indicate that short-term consumption of HC diet negatively impacts the balance of anti-inflammatory defenses and proinflammatory/profibrotic mediators in the heart, which can contribute to HC diet-induced morphofunctional cardiac alterations.
Assuntos
Tecido Adiposo , Citocinas , Animais , Camundongos , Carboidratos da Dieta , Espécies Reativas de Oxigênio , Substâncias Reativas com Ácido Tiobarbitúrico , Dieta , InflamaçãoRESUMO
SummaryPrevious studies have established a model of atresia in preovulatory follicles after stimulation of immature rats with equine chorionic gonadotropin (eCG). This gonadotropin recruits a follicular pool and the deprivation of preovulatory luteinizing hormone (LH) surge induces the atresia in preovulatory follicles. The present study investigated the occurrence of ovulation and provided some morphological features of granulosa cell (GC) apoptosis of atretic follicles at 0, 48, 72 and 120 h after eCG stimulation. Histological sections of ovaries from untreated animals (0 h) showed primordial, primary, secondary and early antral follicles. After 48 h ovaries showed large antral follicles. Preovulatory follicles were observed at 72 h, and two out of five rats displayed cumulus-oocyte complexes (COCs) in the oviducts. All animals exhibited corpora lutea after 120 h. We observed increased estradiol (E2) levels 48 h after eCG treatment that might trigger an endogenous preovulatory gonadotropin surge. Higher progesterone (P4) level, which is the hallmark of a functional corpus luteum, was observed at 120 h. Atresia in secondary and antral follicles was observed by pyknotic granulosa cell nuclei in histology and positive immunolabelling for cleaved caspase 3. We also observed macrophages in secondary and antral follicles in atresia. Transmission electron microscopy revealed GCs with compacted chromatin against the nuclear envelope, nuclear fragmentation, cell shrinkage and fragmentation. No preovulatory follicles showed apoptosis of GCs. In conclusion, our results suggested the occurrence of an endogenous gonadotropin surge, promoting ovulation and preventing atresia of preovulatory follicles.
Assuntos
Apoptose , Atresia Folicular/fisiologia , Células da Granulosa/patologia , Folículo Ovariano/patologia , Ovulação , Animais , Células Cultivadas , Feminino , Células da Granulosa/metabolismo , Folículo Ovariano/metabolismo , Ratos , Ratos WistarRESUMO
Increased energy intake from carbohydrates has been associated with major cardiovascular outcomes. Mice fed a highly-refined carbohydrate (HC) diet develop cardiac hypertrophy and inflammation. During cardiac injury, NLRP3 inflammasome is activated which results in a local inflammatory response. In this study, we hypothesized that a nom-hypoglycemic dose of glibenclamide may reverses sugar diet-induced cardiac damage by NRLP3 inflammasome inhibition. Mice were fed the HC diet for eight weeks and divided into a group treated with glibenclamide (20 mg/kg, gavage) and another with vehicle for four weeks. Afterward, hearts were excised for morphometric analysis and ex vivo function determination. NLRP3 inflammasome activation was investigated by western blotting and in situ fluorescent detection of reactive oxygen species (ROS) and active caspase-1. The HC diet promotes heart hypertrophy and collagen deposition, which were reverted by glibenclamide without ameliorating HC diet-induced insulin resistance. Changes in cardiac performance were observed in vivo by invasive catheterization and in Langendorff-perfused hearts due to the HC diet, which were prevented by glibenclamide. Hearts from HC diet mice had increased levels of NLRP3 and cleaved IL-1ß. Glibenclamide reversed ROS production and caspase-1 activity induced by HC diet. These findings suggest glibenclamide's cardioprotective effects on heart damage caused by the HC diet are related to its inhibitory action on the NLRP3 inflammasome.