Análise dos receptores esteroidais (AR e ERβ) e da sinalização ERK na próstata ventral de camundongos tratados com dieta rica em lipídeos e/ou submetidos exercício físico

Abstract

The prostate is an accessory gland part of the male reproduction system; together, the prostate, seminal vesicle and the testicles are responsible for the semen production. The prostate cancer is the second most frequent cancer among men worldwide. It is known that obesity is able of promoting metabolic dysfunction that affects prostate microenvironment. The objective of this research was to elucidate the prostate response to high-fat diet and the role of physical exercise. We used 20 male adult Swiss mice and they were separated in 2 groups: fed with normal diet (DN – 4% fat), fed with hiperlipidic diet (DH – 40% fat), and within this groups the animals were sedentary (-S) or exercised (E), swimming 1hour per day and 5 days per week. The duration of the diet and the exercised were 16 weeks. Biometric and metabolic parameters of the animals were evaluated and the prostate was analyzed by immunoreactions (PCNA and estrogen receptor-ERβ), western blotting (ERK1 / 2 and androgen receptor-AR) and caspase-3 activity. We found that the fat uptake promoted the weight gain, higher fat-mass (up to 3,7x) and hyperglycemia (average of 200%), besides reducing the testosterone levels. Also, DH stimulated the prostatic cellular proliferation through higher activation of ERK signaling. In addition, the diet promoted a reduction by half of the ERβ content and increased those of AR. Physical exercise per se promoted an anabolic effect by increasing testosterone and stimulating cell proliferation in the prostate of sedentary group. However, exercise was able to reverse all prostate changes caused by the hyperlipid diet. In summary, the association of a hyperlipidic diet and a sedentary lifestyle promotes insults to the prostate stimulating pathways that could trigger proliferative diseases, such as hyperplasia and cancer and physical exercise is an interesting strategy to reverse such effects