Role of physical activity on gene expression of proliferative and angiogenic pathways on prostate, and their implications on prevention of prostatic benign hyperplasia: experimental study

Author(s)

Fernando Mello Fróes da Fonseca

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2017-12-13

Examining board members

Alberto Azoubel Antunes; Fernando Gonçalves de Almeida; Alexandre Iscaife; Miguel Srougi

• Advisor: Alberto Azoubel Antunes

Abstract

Introduction: Sedentarism and obesity have been reported as relevant risk factors for the development of benign prostatic hyperplasia (BPH). In the present work we investigated the role of physical activity in proliferative and angiogenic pathways on prostate and implications for BPH prevention. Methods: Male Wistar rats with eight weeks old were used in this experiment, randomly divided into four groups: 1. physical activity (PA) and normal diet; 2. PA and high fat diet; 3. sedentary (S) and normal diet; 4. S and high fat diet. Food and water were provided ad libitum. The rats in the Groups 1 and 2 were submitted to a swimming training protocol for 10 weeks, executed five times a week with duration of 60 minutes per day. At the end of the protocol, prostate glands were dissected, weighted and stored. We measured prostatic gene expression levels of insulin-like growth factor 1 (IGF1), IGF1/PI3K/Akt proliferative axis and genes related to angiogenesis through the quantitative real-time polymerase chain reaction (qRT-PCR) method, and apoptotic index (TUNEL). Results: After 10 weeks, groups 1 and 2 had less visceral fat when compared to the groups 3 (29,4 vs 37,96 grams; p < 0,05) and 4 (31,87 vs 41,96 grams; p < 0,05), respectively. According to prostate weight, PA decreased prostate growth in normal fed rats (group 1 vs group 3, p < 0,05), but this finding was not shown in high fat fed rats (group 2 vs group 4). When comparing normal fed rats (group 1 vs group 3), IGF1, IRS1 and Akt genes were less expressed in prostate of rats submitted to PA (means 0.22, 0.04 and 0.27 respectively). Those patterns of expressions were also shown when we compared high fat fed rats (group 2 vs group 4), but the IGF1 downregulation was less pronounced (p < 0,001). PA increased the expression of angiogenic related genes (HIF-1alpha, VEGF, VEGFR and mTOR) when comparing rats submitted to high fat diet. Apoptotic index (number of apoptosis per 10 HPF) was higher in rats submitted to PA (9,0 vs 2,0; group 1 vs group 3; p=0,07), (9,0 vs 1,43; group 1 vs group 4; p < 0,05). Conclusion: PA seems to inhibit IGF1/Akt proliferative axis on prostate in both normal and high fat fed rats, stimulates angiogenesis in high fed rats, and increase prostatic apoptosis. These findings can be related to BPH prevention (AU)

• FAPESP's process: 15/02335-5 - Role of physical activity in benign prostatic hyperplasia and vesical dysfunction in rats with metabolic syndrome
• Grantee: Fernando Mello Fróes da Fonseca
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)