Untitled

Funder

Organizational Unit

Publications

Energy restriction, exercise and atorvastatin treatment improve endothelial dysfunction and inhibit miRNA-155 in the erectile tissue of the aged rat

Publication . Rocha, B.; Rodrigues, A. R.; Tomada, I.; Martins, M. J.; Guimarães, J. T.; Gouveia, A. M.; Almeida, H.; Neves, D.

Background: Endothelial dysfunction underlies cardiovascular disease that frequently affects aged individuals. Characterized by local decrease in nitric oxide, it results from down-regulation of endothelial nitric oxide synthase (eNOS) expression/activity. Aiming to elucidate the molecular mechanisms involved in age-related endothelial dysfunction and to unveil potential therapeutic targets, we tested how diet pattern, exercise and atorvastatin modulate the expression of eNOS, inducible NOS (iNOS), endothelin-1, sirtuins (SIRT) and microRNA-155 in the erectile tissue of high-fat fed aged rats. Methods: Sprague-Dawley male rats fed with high-fat diet until they completed 12 months were grouped and subjected to energy restriction (ER), ER and atorvastatin, or, ER, atorvastatin and physical exercise. Controls were fed with standard rodent chow. The blood pressure was measured using the tail-cuff method before sacrifice at 18 months. Glucose, total cholesterol, HDL, triglyceride and CRP were assessed in blood and eNOS, endothelin-1, iNOS and sirtuins were detected by immunofluorescence in the penis sections; eNOS, endothelin-1, iNOS, SIRT2–4 and SIRT6–7 were semi-quantified by western blotting in tissue homogenates. MicroRNA-155 was quantified using RT-PCR in formalin-fixed paraffin embedded sections. To compare the studied variables, two-tail student t test was used. Results: Atorvastatin promotes eNOS expression and is more efficient than ER or exercise in the control of hyperlipidemia and inflammation. Among the studied sirtuins, detected for the first time in the erectile tissue of the aged rat, SIRT2 aligns with eNOS expression. Both proteins exhibit over-expression in animals with combined exercise, atorvastatin and ER. Analysis of microRNA-155 expression also suggests its intervention in the regulation of eNOS expression. ER, particularly when combined with atorvastatin, was able to reverse the increase of iNOS and endothelin-1 in high-fat fed rats. Conclusions: The present results indicate that the association of ER, atorvastatin and exercise is more efficient than isolated interventions in the prevention of endothelial dysfunction.

2018Journal article

Open access

Characterization of TGF-β expression and signaling profile in the adipose tissue of rats fed with high-fat and energy-restricted diets

Publication . Sousa-Pinto, Bernardo; Gonçalves, Laura; Rodrigues, Adriana R.; Tomada, Inês; Almeida, Henrique; Neves, Delminda; Gouveia, Alexandra M.

Transforming growth factor beta (TGF-β) plays an important role in the pathogenesis of obesity, influencing the release of inflammation mediators and promoting remodeling and collagen deposition in the adipose tissue (AT). In this context, this work aims to elucidate whether TGF-β and Smad-dependent or Smad-independent signaling pathways contribute to regional differentiation of AT in high-fat diet (HFD) and energy-restricted (ER) rat models. For this, TGF-β, TGF-β receptors I and II, PAI-1 and GLUT4 mRNA levels were quantified by real-time PCR, and western blotting assays allowed the semiquantification of TGF-β and proteins from Smad3, ERK1/2 and Akt signaling pathways in subcutaneous and visceral (epididymal, retroperitoneal and mesenteric) fat depots from control, HFD and ER-treated rats. HFD was associated to increased levels of TGF-β and PAI-1 mRNA in epididymal and retroperitoneal visceral fat depots, while ER diet induced a reduction of TGF-β mRNA levels in mesenteric, but surprisingly an increase in retroperitoneal fat. Regarding the different signaling pathways, contrarily to what was found for Smad3, activation of ERK1/2 and Akt in response to HFD was detected in all the visceral but not in subcutaneous fat depots. ER-treated rats presented a more heterogeneous signaling response, as well as decreased TGF-β receptors expression, in the different visceral fat depots. In conclusion, subcutaneous and visceral AT respond differently to distinct diet patterns regarding TGF-β expression and activated signaling pathways. Furthermore, the present study points that visceral AT should not be understood as a homogeneous entity since that response also varied in the different fat depots.

2016Journal article

Restricted access