Impact of exercise training on white adipose tissue remodeling in cancer cachexia

• Autor(a) principal: Figueiredo, José Alexandre Cosme
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/25634
• topic: Cancer; Cancer cachexia; White adipose tissue browning; White adipose tissue remodeling; Endurance exercise; UCP1; PGC-1α; Adipocytes morphological analysis

Exercise training has been claimed for its capability of inducing several beneficial adaptations, not only on healthy individuals, but also on a large range of pathologies, cancer included. In the cancer cachexia (CC) set, however, exercise may represent a “double-edged sword”. If by one hand patients may benefit from the many healthy effects induced by exercise training, by other hand, some evidences are pointing exercise as a promoter of the browning that occurs in white adipose tissue (WAT). Indeed, exercise seems to be capable of upregulate the expression of UCP1 and PGC-1α, which can contribute to further enhance the energy expenditure experienced by subjects with CC. This apparent dichotomy makes exercise an interesting and crucial variable to be studied on adipose tissue remodeling level in the cancer cachexia set. The aim of the present study was to evaluate the impact of endurance exercise on the WAT remodeling taking place on cancer-related cachexia. To do it so, a treadmill exercise protocol was implemented in two pre-clinical models, of mammary and prostate cancer using female Sprague-Dawley rats and male Wistar Unilever rats, respectively. Retroperitoneal tissue samples were collected and its protein content, regarding some selected markers of browning and metabolism, were analyzed. In addition, a histological evaluation, aiming to analyze the cross-sectional area and adipocytes number, as well as other remodeling process occurring on WAT, was performed on rats bearing prostate cancer. The obtained results suggested that endurance exercise does not worsen or ameliorates the energy expenditure and the metabolic impairment scenario taking over WAT in cancer cachexia, once no alterations were detected in the expression levels of the analyzed markers. Nevertheless, alterations regarding adipocytes morphology, characterized by a significant decrease of adipocytes areas, was notice for the animals subjected to the endurance exercise protocol. These findings highlight exercise capacity in inducing adaptations on the adipose tissue and evidence exercise practice as a potential beneficial tool on the managing of cancer cachexia.