Efeito do peptídeo Bj-PRO-7a no remodelamento cardíaco em ratos hipertensos

• Autor(a) principal: Jesus, Érika Fernandes de
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/00130000094kw
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/8676
• topic: Bj-PRO-7a; Remodelamento cardíaco; Hipertensão arterial; Hipertrofia cardíaca; Fibrose; Bj-PRO-7a; Cardiac remodeling; Hypertension; Cardiac hypertrophy; Fibrosis; CIENCIAS BIOLOGICAS::FISIOLOGIA

Bj-PRO-7a, a proline-rich oligopeptide isolated from Bothrops jararaca snake venom, was able to reduce blood pressure and heart rate in hypertensive animals. However, it is not yet known whether this peptide may have beneficial effects on cardiac remodeling. Herein, we evaluate the effect of the Bj-PRO-7a in spontaneously hypertensive rats. Normotensive (Wistar) and spontaneously hypertensive (SHR) rats were divided into 3 groups: 1) Wistar treated with 0.9% saline, s.c.; 2) SHR treated with 0.9% saline, s.c.; and 3) SHR treated with BjPRO-7a (71 nmol/Kg/day, s.c.). The animals were treated during 28 days. The systolic blood pressure was weekly measured by tail-cuff plethysmography. At the end of the treatment, cardiac function was evaluated in isolated perfused heart preparation. The ventricular mass index was calculated by the ratio between the left ventricular weight and tibia length. The cardiomyocyte diameter and interstitial and perivascular fibrosis of the left ventricle were evaluated using the Picrossirius staining. The detection of collagen III deposition was evaluated by immunofluorescence. Fibroblast proliferation were assessed by immunohistochemistry to detect proliferating cell nuclear antigen (PCNA). The expression of catalase, SOD and ERK1/2, MMP-2 and MMP-9 was assessed by Western Blot. In our protocol, the Bj-PRO-7a was unable to reduce the systolic blood pressure of the SHRs. However, this peptide attenuated the development of the cardiomyocyte hypertrophy in these animals. Additionally, the deposition of the interstitial and perivascular fibrosis in SHR was significantly reduced by the treatment with Bj-PRO-7a. This peptide did not alter the collagen III deposition in hypertensive rat hearts. The Bj-PRO-7a reduced positive PCNA-labeled fibroblasts. The expression of catalase, SOD and ERK1/2 was significantly increased in SHR, but the Bj-PRO-7a attenuates this increase. The expression of MMP-2 and MMP-9 was not different in SHR hearts, but the Bj-PRO-7a increased the expression of the MMP-2 in the heart of these animals. Our findings demonstrate that the Bj-PRO-7a reduced the pathological cardiac remodeling through mechanism mediated by inhibition of the ERK1/2 and increasing MMP-2 expression. This data suggest that the Bj- xxiii PRO-7a could have a potential therapeutic for the treatment of cardiac diseases.