Treinamento de força e o envelhecimento alteram a atividade das metalopeptidases de matriz (MMPs) em músculos esqueléticos e em soro de ratos

Dissertação (mestrado) — Universidade de Brasília, Faculdade de Ceilândia, Programa de Pós-graduação em Ciências e Tecnologias em Saúde, 2016.O envelhecimento é um processo multifatorial complexo, no qual as propriedades mecânicas do músculo se deterioram o que contribui para perda de função e independência dos idosos, essa deterioração é principalmente devido à perda de massa muscular. É possível que as alterações no músculo esquelético também possam estar relacionadas a matriz extracelular. O objetivo deste estudo foi investigar os efeitos do TF sobre a atividade das MMP-2 e MMP-9 em músculos esqueléticos e soro de ratos jovens e velhos. Vinte e oito ratos Wistar foram divididos aleatoriamente em quatro grupos (n = 7 por grupo): jovem (J); jovens que realizam o treinamento (TJ); velho (V); velho que realizam o treinamento (TV). Foi realizado um período de treinamento de força de 12 semanas, durante o qual os animais subiram uma escada vertical 1.1- usando pesos fixados em suas caudas. As sessões foram realizadas 3 vezes por semana, com 8-12 movimentos dinâmicos por escalada. A atividade da MMP-2 e MMP-9 foram analisadas por zimografia. Houve maior atividade de MMP-2 no gastrocnêmio lateral e músculo flexor profundo dos dedos no grupo TV comparado com o V, J e TJ (p ≤ 0,001). Além disso, houve maior atividade da MMP-2 no músculo gastrocnêmio medial no grupo TV em comparação com o J e TJ (p ≤ 0,001). O grupo J apresentou menor atividade de MMP-2 no músculo sóleo do que o TJ, V e TV (p ≤ 0,001). Com relação à MMP 2/9 no soro, o grupo TV apresentou atividade significativamente reduzida (p ≤ 0,001) em comparação com J e TJ. Estes resultados sugerem que o TF promove um aumento do conteúdo de MMP-2 no músculo envelhecido, enquanto demonstrou uma redução do conteúdo de MMP-2 e MMP-9 na circulação de animais jovens, o que pode favorecer a manutenção de tecido saudável e a imunidade, concluindo assim que o TF é um mecanismo importante para a adaptação do músculo e pode ser fundamental para atenuar os efeitos deletérios associados à idade.Aging is a complex multifactorial process characterized by accumulation of deleterious, including extracellular matrix. The aim of this study was to investigate the effects of twelve weeks of RT on MMP-2 and MMP-9 activity in skeletal muscles and serum of young and old rats. Twenty eight Wistar rats were randomly divided into four groups (n=7 per group): young (J); young that perform the training (JT); old (O); old that perform the training (OT). A 12-week resistance training period, during which the animals climbed a 1.1-m vertical ladder with weights secured to their tails, was used. The sessions were performed once every 3 days, with 8–12 dynamic movements per climb. The MMP-2 and and MMP-9 activity was analyzed by zymography. There was higher active MMP-2 activity in lateral gastrocnemius and flexor digitorum profundos muscle in the OT group compared with the O, Y and YT (p ≤ 0.001). Moreover, there was higher active MMP-2 activity in medial gastrocnemius muscle in the OT group compared with the Y and YT (p ≤ 0.001). The Y group presented lower active MMP-2 activity in solues muscle than the YT, O, OT (p ≤ 0.001). With respect to serum active MMP- 2/9 activity, OT group was significantly reduced (p ≤ 0.001) compared to Y and YT. These results suggest that RT up-regulates MMP-2 activity in aging muscle, while down regulating MMP-2 and MMP-9 in the circulation, which can favor to the maintenance of healthy tissue and immunity

Paternal resistance training modulates calcaneal tendon proteome in the offspring exposed to high-fat diet

The increase in high-energy dietary intakes is a well-known risk factor for many diseases, and can also negatively impact the tendon. Ancestral lifestyle can mitigate the metabolic harmful effects of offspring exposed to high-fat diet (HF). However, the influence of paternal exercise on molecular pathways associated to offspring tendon remodeling remains to be determined. We investigated the effects of 8 weeks of paternal resistance training (RT) on offspring tendon proteome exposed to standard diet or HF diet. Wistar rats were randomly divided into two groups: sedentary fathers and trained fathers (8 weeks, three times per week, with 8–12 dynamic movements per climb in a stair climbing apparatus). The offspring were obtained by mating with sedentary females. Upon weaning, male offspring were divided into four groups (five animals per group): offspring from sedentary fathers were exposed either to control diet (SFO-C), or to high-fat diet (SFO-HF); offspring from trained fathers were exposed to control diet (TFO-C) or to a high-fat diet (TFO-HF). The Nano-LC-MS/MS analysis revealed 383 regulated proteins among offspring groups. HF diet induced a decrease of abundance in tendon proteins related to extracellular matrix organization, transport, immune response and translation. On the other hand, the changes in the offspring tendon proteome in response to paternal RT were more pronounced when the offspring were exposed to HF diet, resulting in positive regulation of proteins essential for the maintenance of tendon integrity. Most of the modulated proteins are associated to biological pathways related to tendon protection and damage recovery, such as extracellular matrix organization and transport. The present study demonstrated that the father’s lifestyle could be crucial for tendon homeostasis in the first generation. Our results provide important insights into the molecular mechanisms involved in paternal intergenerational effects and potential protective outcomes of paternal RT